6.2
Insect Pests in NY State
There are some 17 insects that can cause serious injury to turfgrass in NY State and these belong to six general complexes: white grubs, weevils, chinch bugs, caterpillars, leatherjackets and ants. White grubs are scarab beetle larvae that live in the soil where they prune grass roots or
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Most damaging life stage1 |
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Group |
Common name |
Scientific name |
Name |
Habitat |
Origin |
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White grubs |
Asiatic garden beetle |
Maladera castanea |
Grub |
Root zone |
Exotic |
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Black turfgrass ataenius |
Ataenius spretulus |
Grub |
Root zone |
Native |
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European chafer |
Amphimallon majale |
Grub |
Root zone |
Exotic |
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Green June beetle |
Cotinis nitida |
Grub |
Root zone |
Native |
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Japanese beetle |
Popillia japonica |
Grub |
Root zone |
Exotic |
|
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May and June beetles |
Phyllophaga anxia, others |
Grub |
Root zone |
Native |
|
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Northern masked chafer |
Cyclocephala borealis |
Grub |
Root zone |
Native |
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Oriental beetle |
Anomala orientalis |
Grub |
Root zone |
Exotic |
|
Weevils |
Annual bluegrass weevil |
Listronotus maculicollis |
Grub |
Soil surface |
Native |
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Bluegrass billbug |
Sphenophorus parvulus |
Grub |
Soil surface |
Native |
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Chinch bugs |
Hairy chinch bug |
Blissus leucopterus |
Nymph, Adult |
Soil surface |
Native |
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Caterpillars |
Black cutworm |
Agrotis ipsilon |
Caterpillar |
Soil surface |
Native |
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Fall armyworm |
Spodoptera frugiperda |
Caterpillar |
Foliar |
Native |
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Sod webworms |
Various |
Caterpillar |
Soil surface |
Native |
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Leatherjackets |
European crane flies |
Tipula paludosa, Tipula oleracea |
Maggot |
Root zone, Soil surface |
Exotic |
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Ants |
Mound-building ants |
Lasius neoniger, others |
Adult |
Soil surface |
Native |
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1Grub, caterpillar, nymph and maggot are terms for the immature life stage of different insect groups |
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otherwise disrupt the rooting zone. Weevil larvae begin as stem borers, then crown feeders, and then as adults they become foliage feeders. Chinch bugs are small, fast-moving sucking insects that live at the soil surface. Caterpillars include black cutworms that dwell in burrows at the soil surface, and fall armyworms that move aboveground as foliage feeders. Leatherjackets are the soil-dwelling larvae of crane flies that injure grass both above- and below-ground. Ants are also of relevance because their nests can disrupt the surface of the ground. The injury caused by many of these insects may initially be difficult to differentiate from each other and from certain plant diseases. Nevertheless, control decisions must be based on correct identification of the insect pest, which means recognizing the injury and knowing how to identify the insect complex and insect species involved. This is important because the timing and type of control tactics will depend on the particular species, and also because chemical control products have labels specific to particular groups of insects. To be in full compliance, applicators cannot misdiagnose.
6.2.1 White Grubs
Description. White grubs are the immature stages of scarab beetles and constitute the most diverse, widespread and damaging group of turf pests in the Northeast. In NY these include four native species (black turfgrass ataenius, green June beetle, May or June beetles, northern masked chafer) and four introduced species (Asiatic garden beetle, European chafer, Japanese beetle, Oriental beetle). This pest complex largely occurs throughout the state, with the exception of the green June beetle (largely limited to southeastern NY). The most prevalent species at any one site, however, will depend on local conditions due to diverging habitat preferences. But as many as two to four species might occupy the same patch of turf.
Natural history. Larvae have well-developed mandibles for chewing on grass roots. The younger larvae may ingest a high proportion of organic material in addition to feeding on fibrous roots. All cool season grasses are susceptible, as well as some species of forage, field and nursery crops. While the adults of some species feed and are damaging to ornamentals in their own right (e.g. Japanese beetle, Asiatic garden beetle), the adults of other species do not feed (e.g. European chafer). No adults feed directly on turfgrass.
Larvae are truly subterranean, moving horizontally through the soil to track food resources and moving vertically in response to drought and cold temperatures. Adults are generally strong fliers, mobilizing to locate mates and egg-laying sites. Because of this, many adults does not necessarily translate to many grubs. Local control of adult populations will not solve grub problems, nor will local control of grub populations solve adult problems (e.g. Japanese beetle).
Adults of most species rely on female-produced pheromones to attract males for mating. In the case of European chafer, however, males and females aggregate at dusk around prominent trees, vegetation or structures to find mates; they apparently do not use long-distance pheromones. Adult females lays eggs below ground, either singly or in small groups. After egg hatch, development proceeds through three larval instars, prepupa, pupa and adult.
In NY, most species complete one generation a year and overwinter as third instars. As winter approaches, larvae descend to stay below the frost line, ascending in spring as the frost line recedes. They descend once more for pupation. It is the prepupa that fashions the earthen cell in which the pupa resides until the adult emerges and crawls to the surface. Corresponding to its small size, the black turfgrass ataenius can complete two generations a year and overwinters as an adult. The inverse is true for the large May or June beetle grubs, which may require 2-3 years to complete a single generation.
Most damage is attributed to the large third instar due to extensive pruning (chewing) of the roots at the soil-thatch interface. This damage disrupts water and nutrient flow and, if accompanied by drought stress, the grass will quickly die. High populations can kill extensive areas of turf. Unlike other species, larvae of the green June beetle cause damage by their active tunneling through the root zone, not by direct feeding on roots. Most other nutrition is obtained by the ingestion of soil organic matter rather than living roots.
Diagnosis. Larvae are “C”-shaped, with six legs, and well-developed mandibles. The eight species that occur in NY can be differentiated based on two characters of the abdomen: the raster pattern and the anal slit. The raster pattern is the specific arrangement of hairs, spines and bare patches on the ventral surface of last abdominal segment. The anal slit can be “C”-shaped or straight. With practice and the help of a hand lens, these features in third instars can be distinguished in the field. This is a definitive character for the diagnosis of any white grubs. More information can be found at http://ohioline.osu.edu/hyg-fact/2000/2510.html.
Heavily damaged turf may peel back from the soil like a carpet because the root system has been disrupted or devoured. The soil surface will feel spongy, not firm, underfoot. Above ground, there will be thinning, increased susceptibility to drought and ultimately increased susceptibility to weed invasion. If grub populations do not cause visible damage, then their predators might. The grubbing activities of vertebrates like raccoons, skunks and moles can be highly problematic. It is common that indirect grubbing damage is more troublesome than direct grub damage.
If your goal is to monitor the activity of adults in anticipation of a preventive application around the time of egg hatch, Japanese beetles can be monitored with vane traps (baited with a pheromone and floral lure), European chafer by observing mating swarms, and Asiatic garden beetle by nocturnal sweeping of the grass with an insect net or by its attraction to lights or light traps. More often, however, it is the damaging larval stage that has to be monitored in support of decision-making. To assess larvae, you have to dig. Unlike certain other turf insects such as caterpillars, disclosing solutions will not force white grubs to the surface. Use a golf course cup cutter, bulb planter, or shovel to examine soil cores for grubs in the root zone. Depending on the size of the species, eggs and first instars are relatively difficult to find, while second and third instars are relatively easy to pick out of the soil and assess.
Decision-making. Damage can be predicted by sampling for grubs that have not yet caused significant injury. The best time to sample is early August in southeastern NY and mid-August upstate. Egg hatch and grub development, however, may be delayed by cool or dry weather and may also vary from species to species. A sampling scheme should be based on identified problem areas, susceptible areas, and areas that otherwise require better protection (e.g. front lawns, fairways). High priority and high risk areas should be sampled more completely to reduce the chances of overlooking a damaging infestation.
Thresholds have been established as general guidelines for treatment (Table 6.2.2). If several areas are at or above the threshold, intervention may be warranted. Remember, turfgrass that receives sufficient water and has a healthy root system will tolerate higher numbers of grubs than the suggested thresholds. Extensive research in upstate NY shows that insecticide treatments are needed only 20% of the time on home lawns and golf course fairways. In other words, if the decision-making process is bypassed by the consistent use of an early season preventive insecticide, the application may have been unnecessary four times out of five.
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Number of grubs per |
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Species |
sq. ft |
core1 |
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Asiatic garden beetle |
18-20 |
2 |
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Black turfgrass ataenius |
30-50 |
3-5 |
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European chafer |
5-8 |
Any |
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Green June beetle |
5 |
Any |
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Japanese beetle |
8-10 |
Any |
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Oriental beetle |
8 |
Any |
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Northern masked chafer |
8-12 |
Any |
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May and June beetle |
3-4 |
Any |
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14.25-inch diameter soil core of the standard golf course cup cutter |
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Intervention – Cultural control. There is no specific host plant resistance among turf grasses to white grubs. Kentucky bluegrass and creeping bentgrass, however, have a spreading growth habit that is beneficial for filling in bare patches caused by grubs. Endophyte-enhanced grasses (e.g. some perennial ryegrass and tall fescue) may be more tolerant of drought stress and recover more quickly from grub damage even though they do not confer resistance per se. Soil moisture and fertility affect the expression of damage by white grubs. Actively growing turf with a good root system may tolerate populations up to 50% higher than treatment thresholds without showing signs of injury. The recovery of grub-damaged turf can be hastened with fall fertilization. A high-nitrogen application in the spring, however, is detrimental because it weakens the grass by encouraging shoot development without a good root system. Counteract root loss with regular watering and counteract thinning of the stand with overseeding.
Intervention – Chemical control. There are two basic insecticidal approaches to managing white grubs. One is to wait until problems develop in the fall, and then spot treat with a fast-acting material like trichlorfon. The second is to make a summer application of a slow-acting and long-lasting material, like *imidacloprid, that will prevent subsequent infestations. The dilemma is that the most easily monitored life stage, third instar, is the most tolerant of chemical controls.
The use of a preventive insecticide may be warranted in areas that consistently suffer damaging grub populations, or in risk-adverse situations with high value or high priority turf. One drawback of this approach is that applications are made too early in the season to scout for grubs. Contrary to best IPM practices, this means that thresholds cannot be assessed and that there is no nonarbitrary way to decide to withhold an insecticide intervention. A second drawback is that insecticides with longer residuals will also have longer windows of exposure to nontarget fauna, which have a role in the natural regulation of pest populations and other beneficial processes
In contrast, use of a curative insecticide can be based on thresholds and a decision-making process. While these products will offer some control of large larvae, they will still be most effective if applied when grubs are less than full size and still active near the surface. Aside from the labor and cost of scouting, a main drawback of this approach is that there is usually no second chance if the application fails. Spring treatments are not recommended. At that time of year grubs are feeding vigorously between overwintering and pupation, but they are as large as they are going to get and very tolerant of insecticides. In addition, the spring flush in grass growth can usually compensate for grub damage. Regardless of approach, the goal of treatment is never to eradicate completely, but to reduce the population below damage thresholds.
*Imidacloprid is a broad-spectrum, long-residual insecticide. This compound has become the overwhelming product of choice for white grub control in commercial turfgrass. It mostly functions as a systemic so it should be well watered in to reach the roots where it will be taken up by the plant after an activation period. The optimal time to use imidacloprid is at the time of egg laying and egg hatch. Nevertheless, its long-residual gives it a relatively forgiving window of application, from June to the first half of August. While largely used preventively, before scouting is possible, recent research shows that it may be effective against Japanese beetle as late as second instar. Because this developmental stage can be scouted, it opens opportunities to use imidacloprid as a curative. This approach might be suitable if scouting reveals an undetected and widespread infestation that is predominately second instar Japanese beetle; imidacloprid would be an option to pursue before a widespread application of a curative alternative. But unless a manager has a good understanding of the timing and potential asynchrony of population development (e.g. Japanese beetle can lay eggs over a period of more than two months), caution should prevail.
As of 2005, all commercial applications of *imidacloprid products became restricted-use statewide in NY. In addition, the sale, use, and distribution of consumer products are no longer allowed in Nassau, Suffolk, Kings or Queens Counties.
*†Halofenozide has a similar window of opportunity, although it is most effective against the first and second instars of Japanese beetle and less effective against other grub species. It acts as an insect growth regulator that mimics the action of a natural hormone, disrupting the metamorphosis of larvae. Grubs must ingest the chemical for it to be effective and may take several days to die. The product can be applied from just before egg hatch through early grub development; once grubs reach third instar this product no longer has an effect. The manufacturer recommends application in late June or July to allow time for the chemical to penetrate the soil. It is best to minimize thatch because heavy thatch will prevent the insecticide from penetrating to the area where the insects are feeding. *†Halofenozide does not require irrigation for activation, but it is best to delay mowing until the product has been washed from the grass into the soil.
Trichlorfon is a fast-acting, short-residual insecticide recommended for curative spot treatments. Trichlorfon is highly soluble and penetrates the thatch layer better than most products. It has an extremely short period of residual activity (7-10 days) and a reduced half-life in alkaline soils. This product is recommended as a late-season curative and should be applied after the grubs have been located, up to as late as mid September.
Intervention - Biological control. Three biological control agents are commercially available for management of white grubs in turf: entomopathogenic nematodes, entomopathogenic fungi, and the bacteria that cause milky spore disease. Nevertheless, all alternatives have had poor or inconsistent results in the field. Therefore, while turfgrass managers might experiment with these products, they should not rely on them for grub management in high-priority areas. They may also be better than nothing in areas where cultural management is insufficient and chemical treatments are not allowed.
Entomopathogenic nematodes. Entomopathogenic nematodes can be effective parasites of white grubs. Although they are sometimes as effective as chemical insecticides in laboratory trials, field results have been very inconsistent and failures are common. Reasons for poor field results include insufficient water at time of application, improper selection of nematode species, improper storage and handling of the nematodes, and unsuitable environmental conditions.
Nematodes work in concert with a mutualistic bacterium that they carry in their intestines. The infective juvenile stage of nematodes lives freely in the soil; when the juveniles encounter a suitable insect host, they enter through natural openings (e.g. mouth, spiracle or anus) or are sometimes able to penetrate the insect's cuticle. Inside the host, the nematodes travel to the gut and deliver the lethal bacteria that they vectored inside. The bacteria multiply rapidly, releasing a toxin that kills the host in 1-2 days. The nematodes also multiply inside the host until resources are depleted. At that point, a new generation of infective juveniles exits the cadaver to search for another host in the soil.
Among the available commercial isolates of nematodes, Heterorhabditis bacteriophora is the species recommended for the management of white grubs. They should be applied while grubs are still young and most susceptible and before they have caused significant damage. Follow sampling suggestions above, and apply nematodes in areas where high populations have been confirmed. Many types of pesticide sprayers can be used. Use low pressure (< 300 psi), and remove any screens finer than 50 mesh. A hose-end sprayer or watering can is ideal for small-scale applications. Apply a minimum rate of 1 billion nematodes per acre, regardless of the manufacturer’s directions.
Because nematodes are harmed by ultraviolet light, they should be applied at dusk or on a cloudy, rainy day. The nematodes use the thin film of water surrounding soil particles for movement. Irrigation (1/4 inch) after a nematode application is thereby suggested to optimize soil conditions and to help move nematodes through the thatch. A light irrigation before the application will also reduce the chances of nematodes sticking to grass blades on the surface. Users are advised to check viability by examining nematodes for movement with a hand lens before application and again in a sample collected from the sprayer output.
Fungal entomopathogens. Beauveria bassiana (the “white muscardine” fungus) is a common soil-borne fungus that has been selected for its virulence to certain insect pests. When conidia attach to the insect cuticle, they germinate, penetrate with the growing hyphae, and proliferate within the insect’s body. Moist conditions favor germination, followed by infection of the insect host 1-2 days later, and ultimately death. The white appearance of the cadaver’s surface is due to the conidia produced by the mature reproductive structures of the fungus as they reemerge from the host. These infected cadavers serve as inocula for secondary spread of the pathogen in the environment.
The commercial product of Beauveria bassiana is produced through fermentation. Conidia (spores) are harvested and formulated into a sprayable liquid. Younger white grubs should be targeted because they are more susceptible than third instars. After application, the area should be kept wet to promote germination and subsequent infection. Speed and efficacy of the product will depend on the number of spores contacting the insect, the age and susceptibility of the grub and the environmental conditions. Another fungal entomopathogen product, Met F52, has been approved by the EPA. This is a commercial product based on the fungus Metarhizium anisopliae. A decision on the pending registration in New York is due at the end of 2008, so while this product is not yet available to practitioners in New York, it may be on the horizon.
Milky spore disease. Milky spore disease powder is produced by grinding up living, diseased Japanese beetle grubs infected with Paenibacillus popilliae (formerly known as Bacillus). Commercial preparations of milky spore powder are widely used for the biological control of Japanese beetle. Nevertheless, the efficacy of current formulations has not been scientifically substantiated in the field, leading to questions about the usefulness of this biological control agent for white grub management. Users must also be aware that the bacteria in formulated products have been selected for infectivity to Japanese beetle grubs and are of no value against other common grub species infesting turfgrass in NY. This host specificity is highlighted on the product label. While Asiatic garden beetle, European chafer and Oriental beetle harbor the bacteria in natural populations, the commercial variety is specific to Japanese beetle.
While scouting, you may find milky grubs that are naturally infected with local strains of bacteria. The widespread occurrence of this pathogen under natural conditions means it does have prospects for biological control of white grubs. But, this will depend on further research and development to transfer laboratory virulence into field efficacy, as well as selecting more virulent bacteria that act against more species of scarabs under broad climate conditions. Practitioners seeking alternatives to chemical insecticides should try this product, but they should not count on it.
More information online:
White grub control:
http://www.nysipm.cornell.edu/publications/grubs
http://www.omafra.gov.on.ca/english/crops/facts/08-023w.htm
http://www.pmra-arla.gc.ca/english/consum/whitegrubs-e.html
http://ohioline.osu.edu/hyg-fact/2000/2500.html
Japanese beetles:
http://www.omafra.gov.on.ca/english/crops/facts/92-105.htm
http://ohioline.osu.edu/hyg-fact/2000/2504.html
Asiatic garden beetle:
http://bugs.osu.edu/~bugdoc/Shetlar/factsheet/turf/Asiaticgardenbeetle.htm
Masked chafers:
http://ohioline.osu.edu/hyg-fact/2000/2505.html
Biological control:
http://www.oardc.ohio-state.edu/nematodes
6.2.2 Weevils
Description. The bluegrass billbug (BGB, Sphenophorus parvulus) and the annual bluegrass weevil (ABW, Listronotus maculicollis) are native weevil species. BGB is most injurious in high-cut, lower maintenance turf including home lawns, athletic fields and golf course. It impacts turf throughout the northern U.S. ABW is most injurious in low-cut, high maintenance turf such as golf course greens, tees and fairways. Until approximately 20 years ago, outbreaks were largely limited to southeastern NY, but now the area of impact has expanded throughout New England, into Canada and south to the Mid-Atlantic.
Natural history. For BGB and ABW, females chew holes into the grass stem and insert eggs. Young larvae live as stem borers, chewing and consuming tissue within the relative protection of the stem and filling it up with sawdust-like frass. When they outgrow the stem, older larvae will drop down to the soil surface where they forage out to chew on surface roots and crowns. Adults feed on grass blades but cause little damage. Both species develop through five larval instars, prepupa, pupa and adult. Pupation takes place in the top layer of the soil. BGB has only one generation a year, while ABW has two to three and maybe up to four in southeastern NY.
Adults of both species are relatively active walkers, and largely disperse on foot even though they are capable of flight. In fall, they mobilize to overwintering sites away from developmental areas. BGB adults, for instance, may settle into where sidewalks meet the lawn. ABW will seek out the relative protection of tree litter and tall grass, and may be most prevalent along defined tree lines or hedgerows bordering fairways.
Diagnosis. Adults have long snouts that are the hallmark of the weevils. ABW adults measure ~3/16 in. long, about half the size of BGB (~1/4 in). In addition to overall size, ABW adults can be differentiated from BGB because their antennae arise from the tip of the snout, rather than the base, and because the hind margin of the eye is convex rather than concave. Newly emerged adults, known as “callows” or “tenerals,” are chestnut to brown in color, making the young adults distinguishable from mature adults that are dark grey to black.
Unlike most beetles, weevil larvae are legless with bodies that are straight to slightly curved. Therefore they are easily distinguished from white grubs, which have six legs and a “C”-shape. Their bodies are creamy white in color with a well-defined brown head capsule.
Injury caused by the stem boring and tunneling activities of younger larvae can be revealed through the “tug-test.” Brittle or weakened stems are easily pulled up by hand; unlike white-grub injury, the soil and root zone remain firm and not spongy. BGB damaged turf appears wilted but will not respond to watering. Damage is ultimately expressed as growing brown patches, especially near drought-prone edges such as pavement where grass may be more susceptible to heat or water stress. To distinguish BGB from drought stress, look for the frass in the form of little pockets of sawdust in the thatch or inside grass stems. BGB is most prevalent and damaging in Kentucky bluegrass. Damage will be most apparent from late June into August.
ABW injury is usually expressed as growing areas of yellow and brown spots first noticed around the collar and perimeter of the greens, tees or fairways. Early ABW damage has anthracnose-like symptoms and is frequently confused with this pathogen. Damage will be most prevalent in annual bluegrass, the favored host. It is unknown whether ABW can actually complete its life cycle on other hosts, even though it is capable of feeding on creeping bentgrass and perennial ryegrass. High populations of ABW will cause substantial areas of dead turf in highly visible and prominent areas of golf course playing surfaces.
BGB – Decision-making. In the spring, BGB adults are most active from mid May to June. It is common to see adults strolling across paved areas, in the mid to late afternoon. One way to monitor them at this time of year is with pitfall traps. Make a hole with a standard golf course cup cutter, insert a plastic cup that fills the hole and is submerged to the rim, and add an inch of water with some dish detergent. If 7-10 billbugs fall in over a 2-3 week period, injury can be expected. Another option is to observe adults walking on paved surfaces adjacent to turf in the spring. Injury can be expected if >2 are observed per minute. For the larvae, tolerance thresholds are about 8-12 per sq. ft.
BGB – Intervention. If potentially damaging populations are detected, chemical control applications should be made between mid May and late June. This window targets adults once they have emerged from overwintering sites and before they lay eggs. It is best to mow before the application and irrigate lightly afterwards. This should prevent severe damage by larvae in July and August. If more precision is required, degree day models have been developed to optimize the timing of application.
In areas with persistent problems, host plant selection should be considered. Kentucky bluegrass is one of the most susceptible cool season grasses and should be avoided in favor of more tolerant alternatives. Endophytic cultivars of tall fescue and perennial ryegrass are good options because they reduce BGB survival.
ABW – Decision-making. ABW is challenging to monitor due to its small size. In the spring, mower baskets can be monitored for adults because they are picked up along with clippings. This can be a useful way to stay abreast of when adults are appearing in spring, and, with more careful monitoring, on which areas of the course they are most prevalent. Some areas of the course may always harbor ABW so it is a good idea to monitor consistently those historically affected areas from year to year. Adult ABW reinvade short-mown turf soon after snow melt and soil thaw, from late March to April. A more site-specific approach to monitor adults is to pour a soapy disclosing solution on the turf. This irritant forces adults to emerge from the thatch and ascend to the surface where they can be counted. Shallow soil core sampling or simply digging around at the soil surface/thatch interface will reveal older larvae and pupae. Older larvae look like grains of rice with brown heads; pupae resemble adults but are creamy white until their color darkens before adult emergence. If more detailed information is desired, larvae of all sizes (even stem boring stages) will float to the surface when an infested core is submerged and agitated in a saturated salt solution. This is a good way to confirm that your adult controls were adequate; if too many larvae are found, the application may have been poorly timed to suppress adults and another application against adults of the developing population may be necessary.
Damage thresholds are considered to be 30-80 larvae/sq. ft for the spring generation. Given summer heat stress, thresholds drop to 10-40 larvae/sq. ft. for the summer generation. Nevertheless, field experience indicates that action may have to be taken at thresholds as low as 5-10 larvae/sq. ft in order to avoid injury and minimize the threat of the subsequent generation.
ABW – Intervention. Best control is achieved by targeting early spring adult populations that represent overwintering insects returning to the short mowed turf. A preventive insecticide application is then made to suppress adult populations before the insects begin to lay eggs. The timing of spring applications can be based on a plant phenological indicator. The most widely used is the period that occurs between Forsythia full bloom and flowering dogwood full bract. It is better to make the spring application a little late than a little early, so aim for the time when Forsythia is in full bloom and has already acquired many new leaves (i.e. “half gold/half green”).
Choose a relatively insoluble insecticide that stays in the thatch where adults are active. Chlorpyrifos and pyrethroids are the best options. Water in the application lightly, enough to move the material off the leaves. Widespread fairway applications are usually not necessary. It should be sufficient to limit applications to periphery sprays along historically susceptible greens, collars, tees and fairway perimeters. If this control fails, second generation adults can be targeted again sometime around July 4.
While there are products labeled for larvae, their efficacy is generally inferior to products that target adults. ABW has recently been added to the label of trichlorfon and spinosad and initial research has shown that these products, as well as indoxacarb, may be acceptable alternatives for suppressing larvae when they are outside the stem. Otherwise, if larval thresholds are surpassed, withhold applications and monitor those areas to track development as the population matures from small to large larvae and to pupae. If sampling reveals a preponderance of pupae, delay an application for one week to effectively target the adults. No insecticidal products have activity against the pupae.
With respect to cultural control, minimizing stress (e.g. due to water deficit or traffic) on annual bluegrass might mitigate the effects of ABW. Other than that, reducing the amount of annual bluegrass is the only other option. Overwintering adults are sometimes very abundant in white pine litter, leading some golf courses to remove pine litter or even remove stands of white pine trees. Tree removal is not recommended, however, because these sites are not actually preferred locations for overwintering. Weevils will overwinter elsewhere. We may ultimately be able to define control practices based on managing adults in their overwintering habitats or by intercepting them as they return to developmental sites, but these opportunities have not yet been advanced.
More information online:
Annual bluegrass weevil:
http://www.nysipm.cornell.edu/factsheets/turfgrass/default.asp
http://www.usga.org/turf/green_section_record/2006/jan_feb/the_annual.html
Billbug:
http://www.ento.psu.edu/extension/factsheets/billbugsLawns.htm
http://ohioline.osu.edu/hyg-fact/2000/2502.html
http://www.uri.edu/ce/factsheets/sheets/billbug.html
6.2.3 Caterpillars
Description. Three groups of caterpillars damage turf in NY: cutworms, sod webworms and armyworms. Cutworms and armyworms largely refer to diverging habits of these moth larvae. Cutworms are solitary and tend to chew through and sever the grass stem at ground level, and then move on to the next plant. In contrast, armyworms are gregarious feeders, and tend to move across the turf eating all edible material in their paths. While there are a few species that can be injurious in turfgrass of NY, the main species of concern are the black cutworm (BCW, Agrotis ipsilon) and the fall armyworm (FAW, Spodoptera frugiperda). Sod webworms are a complex of species. Unlike the sod webworm, FAW and BCW do not usually overwinter in NY because they are too cold intolerant. Migratory adults reinvade the state every spring from populations that overwinter in the southern U.S.
Sod webworms. Sod webworms are only sporadic pests and the cases are actually few where the larvae become problematic, despite the large numbers of adults that may be seen. Adults have snout-like projections on their face (thereby their common name “snout moths”) and have their wings folded close to the body when at rest. They are buff-colored and 0.5 - 0.75 inches long. They hide during the day. When disturbed by mowing, or at dusk, they fly in a zigzag pattern and are easy to spot.
The larvae construct silk-lined burrows through the thatch layer and into soil. They will incorporate debris such as soil, sand and grass clippings in the tunnel walls. They forage out from burrows at night. Larvae are brown to green with darker spots and will measure 0.2 - 1 inch long. Foraging birds may indicate infestations. Habitat preferences are for sunny areas, and they can affect low to high maintenance turf (e.g. home lawns and golf course turf). Sob webworms overwinter as larvae.
Damage starts as small patches of yellowing or browning grass, or grass clipped off at ground level. Look for small piles of green frass where grass is turning brown. On low-mown turf, sod webworm damage can resemble disease, and will cause small depressed marks of brown grass that will grow in size.
The highly visible adults often concern home owners, but their presence does not indicate a pest problem. Therefore, the lawn has to be monitored for the larvae. More often than not, damage attributed to sod webworm on residential lawns is actually just drought stress—another reason it is important to scout for larvae. Scout for larvae two weeks after adult flights, when caterpillars from the new generation will be present. Caterpillars should be scouted near brown patches by spreading the grass and looking into the thatch to find the frass. Another way is to flush them to the surface using a soapy disclosing solution. The standard method is to mix 1 fluid ounce lemon-scented dish detergent in 2 gallons water and apply it over to 2-3 square feet of turf. The soap acts as an irritant, causing the larvae to emerge from hiding.
If there is enough damage and larvae to warrant control, it is best to use a less soluble insecticide such as pyrethroids that will stay in the thatch. A product should be applied as late in the day as possible because larvae are most active at night. It should be watered in lightly, just enough to wash it off the leaves and into the thatch. Spinosad and Bt are biopesticide alternatives to conventional chemical insecticides.
Black cutworm – Natural history. BCW is common in low maintenance turf, but is particularly damaging in golf course greens and tees. Adult moths reinvade NY in spring from the southern U.S. along with spring storm fronts. This species is apparently incapable of overwintering in areas where the soil freezes. BCW will achieve 2-3 generations a year in NY. Adults feed on flowers at night and then locate sites in the turf where they attach eggs to the tips of grass blades. Small larvae move and feed on the surface. Older larvae, however, fashion a protective burrow in the turf from which they foray to feed. These burrows lead into the soil and are about the size of a pencil hole.
Black cutworm – Diagnosis and Decision-making. BCW adults are dark grey and mottled with black and brown. Larvae bear a pale stripe down the back, a greasy or oily appearance, and have a surface integument that is rough or pebbly. Mature larvae will get to be 1-2 inches long. Nocturnal feeding by the larvae will scalp grass around the burrow’s entrance, leaving irregular depressions that resemble ball-marks. Low-mown bentgrass is particularly susceptible to damage. Like sod webworms, foraging birds may help to indicate the presence of larvae.
The initial spring appearance of adults in NY can be monitored using either black light or pheromone traps set out early in the season (mid-March in southeastern NY). Both traps have limitations. Pheromone traps are relatively inexpensive and simple to maintain, but catch only male moths. While black light traps capture both male and female moths (along with a wide range of other insects), they are expensive and labor intensive. Because storm-driven moths are deposited randomly, there is no guarantee that lack of captures means that no females are present, nor is there any way to equate capture numbers to infestation levels; thus the usefulness of these traps is limited. A positive capture means only that chances are good that females are present and that larvae may appear within a week.
Monitoring for larvae should begin a week after the initial moth trap catches, using the same soap drench method for sod webworms. Apply the drench to 3-4 spots on the green to detect the presence of larvae. On golf course putting greens, damage may not be noticed until the larvae are quite large or have reached the fourth instar. At this point, the disclosing solution can confirm the diagnosis of cutworm damage, which superficially resembles ball marks or even dollar spot. Pest management strategies, however, should target detection and treatment of cutworms before this stage. Thresholds will vary widely from greens and tees to fairways. While the visible damage of only 3-4 large larvae on greens might require a control, turf maintained at a higher cutting height can tolerate much higher populations before thinning is apparent.
Black cutworm – Intervention. Cultural control takes advantage of the fact that BCW lays the majority of eggs on the terminal portion of leaf blades, regardless of grass mowing height. Most cutworm eggs can therefore be removed if the clippings are collected. These should be discarded at least 100 feet away from susceptible turf areas to prevent return migration of the newly hatched caterpillars. Although endophytic varieties of perennial ryegrass and tall fescue are not resistant, larvae do shun feeding on Kentucky bluegrass. A 30-foot buffer of this grass around a green significantly reduces the incidence of cutworms since they are less likely to cross this barrier to settle on the greens. Another alternative is to mow greens early in the morning, between 2 and 4 a.m., when cutworms are actively feeding on the surface. Target these mowings for three consecutive nights during the early instars of each cutworm generation.
Spinosad is a potential preventive treatment when applied every 3-4 weeks. Otherwise, a range of chemistries work well for the curative control of BCW. Early-season detection and treatment is desirable because younger (smaller) cutworms are more susceptible than older (larger) cutworm. Higher rates might be required for the control of large larvae and for control in high-mown turf. Regardless, after application, irrigation and mowing should be withheld for 12-24 hours so larvae can contact the treated foliage.
Besides spinosad, Bt is a biopesticide alternative to conventional chemical insecticides. Bt is a non-living form of the bacteria Bacillus thuringiensis that is sold and labeled for management of caterpillars, including black cutworm, sod webworm and fall armyworm. This microbial toxin will also be most effective when targeting smaller and (≤1/2 in. in length) and more susceptible larvae. As with chemical treatments, mowing and irrigation should be withheld 12-24 hours.
In the area of biological control, entomopathogenic nematodes have a good chance of success in managing BCW. Use the species Steinernema carpocapsae, and as with the biopesticides, apply when caterpillars are small, and follow the recommendations described in the section under white grubs. Finally, keep in mind that a diverse array of naturally occurring enemies, such as parasitic wasps and flies, ground beetles and rove beetles, act to help suppress cutworm populations.
More information online:
Black cutworm:
http://turf.lib.msu.edu/2000s/2008/080311.pdf
http://www.ento.psu.edu/extension/factsheets/black_cutworm.htm
http://www.uri.edu/ce/factsheets/sheets/cutwormsturf.html
http://bugs.osu.edu/~bugdoc/Shetlar/factsheet/turf/Blackcutworm.htm
http://entomology.unl.edu/turfent/documnts/cutworms.shtml
Fall armyworm:
http://www.oznet.ksu.edu/dp_hfrr/extensn/problems/FallArmyworm.htm
http://www.ces.ncsu.edu/depts/ent/notes/O&T/lawn/note128/note128.html
Sod webworm:
http://www.ento.psu.edu/extension/factsheets/sodWebwormLawns.html
http://iaa.umd.edu/umturf/Insects/Sod_Webworm.html
http://ohioline.osu.edu/hyg-fact/2000/2011.html
http://www.uri.edu/ce/factsheets/sheets/sodwebworm.html
6.2.4 Chinch Bugs
Description. The hairy chinch bug (HCB, Blissus leucopterus hirtus) occurs throughout NY, west to Minnesota, south to Virginia and north to Ontario and southeast Canada. Home lawns are the most susceptible turf systems, and there the insect is most prevalent in areas with thick thatch, well-drained sandy soils and full sunlight. In addition, HCB is recently being recognized as an occasional pest on golf courses where it has traditionally been of little concern to superintendents.
Natural history. HCB has piercing-sucking mouthparts that permit nymphs and adults to extract sap from the crowns and stems. This causes injury that produces drought-like symptoms. Most of the cool season grasses are susceptible to feeding. Both life stages are active and agile in the thatch and on the soil surface. HCB tends to form aggregations and this leads to patches of localized damage.
Although adults are capable of flight, they largely disperse by walking. The adults will move to overwinter in protected sites with thatch or tall grass, in debris and around structures. When they re-emerge in the spring, egg laying is preceded by a nearly 2-week preoviposition period. Up to 170 eggs per female are laid in leaf sheaths and on the ground near the base of host plants. Nymphs require 4-6 weeks to develop through five instars. One generation per year is most common in upstate NY and two generations is probably most common downstate.
Diagnosis. HCB are small and relatively fast-moving insects. Adults are 3/16 in. long, with shiny white wings. Nymph coloration varies from red to orange to brown. If captured by hand, a pungent, fruity smell may be emitted by odoriferous defensive glands on the abdomen.
The habitats most susceptible to HCB damage are home lawns with full sun and sandy soil where grass is more susceptible to drought stress. Abundance of the insect and severity of its injury are also favored by thick thatch. July and August are the months when the insect is most active and when most damage is expressed. HCB feeding causes symptoms that resemble drought stress and is often misdiagnosed as such. Unlike drought damage, however, lawns that are heavily damaged by HCB will not recover once wet conditions are restored. Affected grass will turn yellow and then reddish-brown. Injury may be more prominent on the edges of paved areas.
Searching the soil surface should reveal the nymphs and adults. The tiniest nymphs are bright orange/red, and the adults are quick, which makes them relatively easy to spot despite their small size. HCB can also be detected and monitored with a flotation cylinder. Choose a spot on the fringe of a patch of damaged grass. Pound an open-ended coffee can ~2 inches into the soil, fill it with water, and look for the adults as they float to the surface. Add more water as required if it filters into the soil. A 5-10-minute observation should be sufficient. A variation is to cut a square of turf and submerge it in a pan filled with water.
Decision-making. If an infestation of HCB is detected, make several observations with the flotation cylinder at the margin of the affected areas. More than 20 HCB per cylinder means that action should be taken to avoid loss of turf. Thresholds can also be made with direct visual counts. More than 10 individuals found in a 60-second search of 1 sq. ft. has been used as an action threshold, as has 20-30 per sq. ft. in a detailed search. Make these abundance estimates at several sites around the affected area.
Intervention. Host plant selection is one form of cultural control. Heavily or consistently damaged lawns should be renovated with a more tolerant grass variety. Studies have shown there to be a great deal of variation in HCB susceptibility across different cool season grass species and varieties. Endophytic cultivars of tall fescues and perennial ryegrasses are good options because they are resistant to HCB. Reducing thatch buildup should also lessen the severity of infestations.
Beauveria bassiana is a naturally occurring entomopathogenic fungus that can suppress populations. Spring and early summer irrigation help to favor this fungus and promote its activity in the natural regulation of HCB. There is also a commercial formulation of B. bassiana that could be tried as an alternative to conventional chemical insecticides.
The traditional window for insecticidal control is mid summer when HCB is most active. The optimal time is after overwintered adults have stopped laying eggs and before the nymphs from their earliest eggs have matured to adults. Some studies, however, indicate that overwintering adults can also be targeted in early spring before they lay eggs. Turf should be watered before any chemical treatment with 15-20 gallons water per 1000 sq. ft. Granular materials should be watered in after application.
More information online:
http://entomology.unl.edu/turfent/documnts/chinchbg.shtml
http://www.usga.org/turf/green_section_record/2006/jan_feb/resistant.html
http://www.omafra.gov.on.ca/english/crops/facts/08-019.htm
http://www.ento.psu.edu/extension/factsheets/chinchBugs.htm
http://www.uri.edu/ce/factsheets/sheets/chinchbug.html
http://ohioline.osu.edu/hyg-fact/2000/2503.html
6.2.5 Ants
Description and Natural history. Mound-building ants are nuisance pests in golf courses of the Northeast. The turfgrass ant, Lasius neoniger, is probably the most troublesome and widespread species. This small, brown ant typically builds mounds that are concentrated around the edges of sand-based greens. A single nest may have several entrances, each with a squat volcano-shaped pile of soil. The main nest is usually located in the surrounding native soil. Mounds pushing up from within sand-based greens are typically the supplemental garrisons made by foraging workers. Mounding activity begins in early spring, increases through early summer, and declines by late summer at which point winged reproductive adults emerge and mate. Fertilized females then locate sites to overwinter and establish new colonies the following spring.
Decision-making. Monitoring for mound-building ants should begin with mid-summer mapping of problem areas across the golf course or other turf habitat. Then, early in the following growing season, monitor for ant activity in the areas that had high mound pressure the previous season. This is where control measures will need to be focused. Beyond greens, if mapping shows that the ants are moving in from golf course roughs, treatments can be targeted at the rough/fairway interface.
Intervention. Insecticides should only be expected to suppress, not eliminate, ant populations. Killing the colony’s queen is difficult, and even if she dies, she can be replaced and the colony will persist. Ant colonies are most susceptible in the early season, when they are small and the queen is relatively weak from overwintering. When applied early, surface insecticide such as pyrethroids and chlorpyrifos can give 4-6 weeks suppression. Those applied later in season, however, may only offer 2-3 weeks suppression.
Insecticidal controls should focus on the perimeter of greens, collars, and roughs adjacent to main nests. This will best target the colony at the entrances to the main nest. An application made to the surface of the green itself will target the entrances of the auxiliary tunnels, but miss the main nest entrance that may be less visible in the higher-mown turf of the collar or rough.
There is mixed advice about using baits as part of a control program. The baits are granular products that contain insecticides and are broadcast applied on and around ant mounds in turf. They may be most effective when used after an initial knock-down application of a pyrethroid. However, the granule size of many baits may be too large and because these ants are generalists, the baits may not always attract them.
More
information online:
http://www.usga.org/turf/green_section_record/2004/july_aug/nuisance.html
http://grounds-mag.com/golf_courses/grounds_maintenance_ managing_nuisance_ants/
6.2.6 Exotic Crane Flies
Description. Exotic European crane fly pests of turfgrass were detected in NY for the first time in 2004 and since then they have emerged as tremendously injurious insects. The larvae are the damaging life stage, commonly referred to as “leatherjackets” (although this may actually refer to the exuvia left behind when the adult emerges from the pupa). Two species were detected in western NY, Tipula paludosa (the “European crane fly”) and Tipula oleracea (the “common crane fly”). Both species are native to Europe but have become established in the Pacific Northwest and British Columbia where they were first detected in 1965. Tipula paludosa was previously established in Nova Scotia (1955). More recently, T. paludosa has established and become widespread in southern Ontario where it was first detected in 1996. In NY, 2004 populations were only detected in Erie and Niagara counties. By the end of 2008, T. paludosa had been detected in four counties (Erie, Monroe, Niagara and Ontario) while T. oleracea had become more widespread, being detected in 13 counties (Erie, Livingston, Monroe, Nassau, Niagara, Onondaga, Ontario, Oswego, Seneca, Suffolk, Tompkins, Wayne, Wyoming). Based on these observations, there are probably two separate areas of establishment, the western Erie Canal corridor (both species) and Long Island (T. oleracea). Until we build awareness and establish safeguards to curtail range expansion, movement of infested materials could spread locally and regionally, across NY and into New England and the Mid-Atlantic.
Natural history. The majority of the crane fly lifecycle is spent in the damaging larval stage. The short-lived adults of both exotic crane fly species resemble oversized mosquitoes, but they do not feed and are non-damaging. Adults are 2.5-3.0 cm long, pupae 3.0-3.5 cm, mature larvae 3-4 cm and eggs 1.0 x 0.5 mm.
Tipula paludosa completes one generation a year, with the emergence of adults occurring over a period of 2-3 weeks in September and October. Adult females will emerge, mate and lay most of their eggs all within the first day of their brief reproductive lives, however adults may persist for several days. Each adult female will deposit up to 200-300 black eggs at or near the soil surface; these eggs will hatch into larvae in about 10 days.
Larvae of T. paludosa develop through four instars before they pupate. Active larvae mostly inhabit the top 3 cm of the soil where they feed on root hairs, roots and crowns of grass hosts. On warm humid nights larger larvae may emerge to forage on stems and grass blades on the soil surface. Larvae usually achieve third instar by the time cold temperatures force them to overwinter. Most damage is attributed to the feeding of rapidly growing fourth instars in spring. By early to mid June, larvae have achieved their maximum size and move 3-5 cm deep in the soil. They remain in a non-feeding stage until pupation, which ends when pupae wriggle to the surface so the adult fly can emerge. The empty pupal cases (exuviae, or the “jackets” of the leatherjackets) look like small grey-black twigs protruding from the sward where they can be spotted on low-mown turf such as golf course playing surfaces.
The biology of T. oleracea is quite similar to T. paludosa. Nevertheless, certain differences mean that management has to be tailored to the specific species. A major difference is that T. oleracea completes two generations a year, emerging in two peaks, one in spring (early May in western NY) and the other in fall coinciding with T. paludosa. T. oleracea larvae never enter an extended aestivation period similar to that of T. paludosa. Larvae overwinter as fourth instars and pupation occurs in early spring. Adult T. oleracea differ from T. paludosa in being more capable fliers, with females laying eggs over the course of a few days.
Eggs of both species are sensitive to moisture and require wet conditions to hatch and survive. Larvae also do best under moist conditions, but once they are third and fourth instars they are quite tolerant of drought. Overall, mild winters and cool summers will probably favor crane fly populations. Other turf conditions such as areas with thatch buildup, poor drainage and regular irrigation will likely favor crane fly survival and population buildup.
Diagnosis. There are hundreds of native crane fly species in NY and a few of them inhabit grassy habitats and can be found emerging from turf. Native species are ostensibly non-damaging because none have been implicated in any turf injury in NY. Because of this, it is important to differentiate the injurious exotic species from the natives. The best physical character to separate them is based on wing pattern. The two exotic Tipula species have a narrow smoky band on the leading edge of the wing adjacent to a bordering whitish band. Unlike many native species, they have no other pigmentation on the wing. One widespread and locally abundant native species, however, is only differentiated because there is a break in the smoky band. Beyond that, characteristics of the male genitalia, ventral distance between the eyes, number of antennal segments, and length of the wing with respect to length of the abdomen permit the differentiation of exotic crane flies from native species, and T. paludosa from T. oleracea. Nevertheless, species identification should be made by a specialist.
Leatherjackets are serious pests of both low and high maintenance turf, from home lawns, golf courses and sod farms, to (based on experience in the Pacific NW), pastures and grass seed fields. Since first detection in 2004, infestations of invasive crane flies in turfgrass have already risen to highly damaging levels in NY. Spring densities of up to 70, 120 and 50 larvae/sq. ft in highly damaged lawns, fairways and putting greens, respectively, have been recorded in the greater Buffalo and Rochester areas. Five categories of damage have been observed: nuisance populations of adult flies and larvae in suburban settings, thinning damage to home lawns, scalping damage to golf course putting greens, thinning and die-back on golf course fairways and rough, and vertebrate predation due to skunks and birds.
Due to the relatively synchronous emergence of local adult populations, homeowners in suburban settings have experienced nuisance swarms of adults. Adults will settle on the sides of buildings, windows screens and landscaping plants, and the public may mistake them for giant mosquitoes. In fact, the first reports of invasive crane flies for both Long Island and the Rochester area were made by homeowners. High larval densities may also act as nuisance populations at times when larvae are active on the surface, a rain shower will wash them off sloped lawns and amass them as piles of maggots in culverts.
On affected home lawns and golf course fairways, root pruning leads to white grub-like damage. The disruption of the rooting zone promotes rapid die-off when the injured turf is drought-stressed. Another expression of injury on home lawns is extreme thinning due to surface feeding. Early to mid-May is when injury is most likely to be expressed by T. paludosa because large larvae are feeding rapidly as they approach the end of development. On affected golf course putting greens, foliar feeding by larvae on crowns and leaf blades causes damage akin to black cutworms. Larvae will reside in aerification holes or in self-made burrows from which they forage to feed, scalping quarter-sized circles on the playing surface.
Monitoring. To detect the presence of exotic crane flies, the leathery pupal cases can be monitored on tees, greens and fairways where they protrude from the low-mown turf. At peak emergence times adults are very abundant and highly visible as they flit about low in the grass. Adults may also congregate during the day on the sides of buildings, sliding doors, window screens and fences. Because adults lay eggs so soon after emergence, they do not move far from the site of larvae incidence. Therefore, sites with abundant adults, larvae or pupal cases should be monitored as an indication of sites where eggs of the next generation are likely to be laid. If a crane fly infestation is suspected, send adults, larvae or pupal cases to a specialist for proper identification. Observations on the abundance of those life stages could help diagnose the problem, since it is not yet possible to reliably distinguish larvae and pupae from native crane fly species.
If signs of insect activity and turfgrass injury suggest leatherjackets, core sampling is the best way to detect and sample larvae. Exotic crane fly larvae can be monitored in the late fall or early spring. Take samples with a cup cutter and rip apart the core to look for larvae. Traditional soap-based disclosing solutions are not very effective in driving the larvae to the surface. Certain insecticides such as pyrethroids and carbamates, however, will reveal the presence of larvae because many will die on the surface. Adults are best captured with a sweep net, but they can also be seen flitting about in grassy areas or perching on nearby vegetation.
Decision-making. Control tactics should be directed against the larvae because adults are hard to target and short-lived. Depending on the overall health of the turf, suggested thresholds are 15-50 larvae per ft2. Fall thresholds are likely to surpass these thresholds, however it is important to keep in mind that leatherjackets can suffer very high mortality between late fall and early spring due to predation by birds and other vertebrates. Vigorous turf can therefore support relatively high populations.
Intervention – Cultural control. Because of their relative sensitivity to dry conditions, careful manipulation of soil moisture levels may be a key cultural tactic to reduce populations. Some strategies might be to regulate the timing and frequency of irrigation, particularly during the oviposition period, to better drain chronically infested areas and to allow the sward to dry (i.e. avoiding irrigation) in the fall. Maintaining a vigorous stand that is more tolerant to infestation might also alleviate problems.
Intervention – Chemical control. The two main control windows are late fall and early spring. A late fall preventive application is recommended if populations of both species occur at the same site. Timing should be after peak emergence of adults in order to overlap the period of egg hatch and first instars. Since adults of both species emerge during a similar window in September, small larvae of both species would be susceptible to preventive insecticides.
Otherwise curative applications for T. paludosa can be made in early spring after scouting has assessed populations or once feeding damage is detected. Tipula oleracea is probably not susceptible during this window because it pupates early in spring and insecticides are not active against pupae.
The aforementioned control windows, unfortunately, do not coincide with other turfgrass pests. The arrival and spread of these exotics thereby represents a worrisome new economic burden for turfgrass managers. To identify the best chemistries for invasive crane fly control in NY, a series of field efficacy trials has been conducted against T. paludosa. Based on consistency and efficacy, bifenthrin, carbaryl, and trichlorfon are confirmed as acceptable products for preventive fall control, followed by imidacloprid and indoxacarb that gave positive but more variable results. For curative spring control the most acceptable products are imidacloprid, indoxacarb and trichlorfon.
Intervention – Biological control. In addition to registered chemical insecticides, a registered biological control option is Beauveria bassiana, an entomopathogenic fungus. The entomopathogenic nematode, Steinernema carpocapsae, is a biological alternative that has been promoted in the Northwest.
More information online:
Northeast:
http://www.nysipm.cornell.edu/factsheets/turfgrass/default.asp
http://www.omafra.gov.on.ca/english/crops/facts/turf_leather_may2198.htm
Pacific Northwest:
http://www.ipm.ucdavis.edu/PMG/r785301411.html
http://whatcom.wsu.edu/cranefly/
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