White grubs

Several species of grubs occur in New England. The most widespread species is the Japanese beetle. The European chafer is found in several locations in eastern and western Massachusetts (especially “inside” Route 495, and along the coast as far north as mid-coast Maine). The Oriental beetle is active in Connecticut, Rhode Island, coastal Massachusetts, and along the Connecticut River Valley. As a general rule European chafers and Oriental beetles are harder to manage than Japanese beetles. In addition, there have been a few occasions where Asiatic garden beetles have caused damage, although the damage from this species is usually most severe in less well maintained turf.

Management of white grubs is most efficient when the specific population causing turf damage is identified. Because some insecticides are less effective against Oriental beetle or European chafer, species identification has become increasingly important for management decisions. Identification of a white grub is made based on its raster pattern. A raster is the pattern of bristles on the underside of the last abdominal segment of the grub. Refer to Figure 1 for illustrations of the various grub rasters.

Damage - Damage from white grubs initially resembles drought stress, with general thinning and/or yellowing of turf. In some circumstances, skunks, raccoons or birds may tear apart turf in infested areas to feed on grubs near the surface, often dramatically increasing the extent of the damge.

Scouting - Use a shovel or spade to cut three sides of a square in the turf anywhere from 6” to 12” on a side, 3” to 4” deep. Flip the sod back on the uncut (fourth) side, turf side down, and use a hand trowel to dislodge soil in the soil/thatch interface. Alternatively, you can use a golf course cup cutter (4.25” diameter) to collect soil samples. The cream colored grubs will be very visible against the dark soil background. Place grubs in a container and count them after removing all of them from the sample area. Convert the area to square feet (e.g., 6” sides = 0.25 sq. ft.). Note that a standard golf course cup cutter is equivalent to 0.1 sq. ft. Take several samples and then calculate the average number of grubs found. For ease in averaging, make all sampling cuts the same size.

Note that weather and soil moisture conditions will affect grub behavior and movement. In very dry or very warm conditions, grubs will move deeper in the soil profile (so sampling holes must be dug deeper). In very moist conditions, grubs will either be closer to the surface or will move laterally to higher or better draining locations.

In the autumn or in early spring, grubs respond directly to soil temperatures. European chafers tend to remain in the root zone later in the fall and return to the root zone earlier in the spring than other species of grubs. Japanese beetles and Oriental beetles tend to respond to daily temperature fluctuations. On warm days in late fall or early spring, the grubs will move up into the root zone and feed, while on cold days or after very cold nights, grubs will remain several inches below the soil surface.

Figure 1. Raster patterns of turf-infesting grubs (drawings not to scale).

Adapted from Haruo Tashiro: Turfgrass Insects Of The United States And Canada. Copyright (©) 1987 by Cornell University. Used by permission of the publisher, Comstock Publishing Associates, a division of Cornell University Press.

Black turfgrass ataenius

The black turfgrass ataenius (BTA) is a small species of white grub. The BTA life cycle is quite different from other grubs. It spends the winter in the adult stage, and females lay eggs in late spring. These eggs hatch into small grubs that feed throughout the month of June and into early July. In many years the grubs pupate and the new adults lay eggs in late July for a second generation. Black turfgrass ataenius is only a pest of concern on golf courses and other very low-mown sports turf (i.e. tennis, croquet) in New England.

Damage - Damage resembles that of other white grubs. Roots can be destroyed and damaged turf may peel back easily. Damage sometimes is more severe in areas with high levels of soil organic matter.

Scouting - Grubs can be found by taking a soil sample, cutting a small section of turf to a depth of 2” to 4” and inspecting the soil for tiny (less than 0.5”) grubs. Adults often are seen on the surface of putting greens, especially on warm sunny days in the spring. To scout for adults, force them to the surface with a soapy flush (irritating drench).

Chinch bugs

The hairy chinch bug (Blissus hirtus), the most common species in the Northeast, prefers ryegrass and fescues but will attack other lawn grasses as well. Adult chinch bugs are about 1/5-inch long and black with white markings on the wings. Nymphs (immature stages) have the same general shape as the adult but lack wings and often have red or orange markings.

Damage - Damage is often confused with drought stress, and normally occurs during July and early August. Injury (wilted or browned out areas) is most severe in sandy soils and in sunny areas. Small patches gradually coalesce into large areas of wilted or dead turf. Chinch bug-damaged turf may not recover in September when other turf comes out of drought dormancy.

Scouting - Use a cup cutter or similar device to remove cores of turf about 4” to 6” in diameter, place the cores in a bucket, and fill the bucket with water. Wait about five minutes. Chinch bugs (and big-eyed bugs, a beneficial insect) will float to the surface of the water. Chinch bugs can also often be observed directly by inspecting the foliage and thatch.

Sod webworms and cutworms

Sod webworms and cutworms are moths that cause damage to turf in the caterpillar stage of their development. In webworms, the color pattern varies with the species and plant source, but most are greenish, grayish, or brownish, and usually have dark spots scattered along the body. The black cutworm, the most common cutworm species in New England, is normally dark gray or nearly black but may have a hint of green in the stripes. Webworms are more likely to cause damage in lawn settings, while cutworms are more frequently encountered on golf courses and other closely-mown turf areas.

Damage - Damage usually begins as small discrete brown patches which can coalesce into larger areas of damage. A finger inspection of the infested area will sometimes reveal sod webworm burrows lined with green frass (insect excrement). Cutworms are often active around aerification holes on golf course greens.

Scouting - Prepare an irritating drench by mixing one fluid ounce of lemon scented dish detergent in one to two gallons of water in a pail. Spread this solution over an area about 2’x2’. Wait three to five minutes. Webworms and cutworms (and earthworms) will be irritated by the soapy solution and will crawl to the surface of the turf area. Note: The soapy solution can burn turf, so on sunny days, and on bentgrass or Poa annua turf, rinse the sample area with clear water after you have completed the insect count.

Annual bluegrass (Hyperodes) weevils 


The annual bluegrass weevil (Listronotus maculicollis, also sometimes referred to as the Hyperodes weevil) is a significant golf course pest in many parts of the Northeast and Mid-Atlantic states. Annual bluegrass weevil is only a pest of concern on golf courses and other very low-mown sports turf (i.e. tennis, croquet), and is not found in higher-cut turf. The insect overwinters in the adult stage. Adults emerge in the spring and migrate from overwintering sites to lay eggs in turfgrass leaf sheaths (almost exclusively annual bluegrass). Following egg hatch, feeding of the tiny larvae becomes increasingly more aggressive up until pupation and the final transition to the adult stage. The annual bluegrass weevil may complete two or three generations per year in New England.

Damage - The most severe damage normally occurs from early June through mid-August, with moderate damage possible at other times of the summer as well. Damage begins as small yellow patches, often along the edges of fairways or on collars around greens, and spreads into large areas. Severely damaged areas take on a water-soaked appearance. Damage is most often restricted to short cuts (fairways and shorter) of annual bluegrass. However, field observations have confirmed that annual bluegrass weevils will feed on creeping bentgrass under certain conditions.

Scouting - Use a cup cutter or similar device to collect cores of 4” to 6” diameter. Loosely break up the soil in the cores and place the loosened soil and all plant matter in a dish pan or similar plastic container. Fill the container with lukewarm water and wait about five minutes. Weevils in all stages of development (except eggs) will float to the surface of the water, where they can be counted. You can also use a saturated salt solution to force larvae to the surface of the water. Large larvae and pupae are visible in turf samples without using flotation techniques. A leaf blower can be reversed and used to vacuum adults from an infested area. Insert a gauze bag in the end of the tube to collect the insects.

Bluegrass billbugs


Bluegrass billbugs can cause serious damage to lawns, particularly those which are predominantly bluegrass. They occur sporadically in New England. Billbug adults are black beetles with very elongated “snouts.” The total body length is about 1/4-to 3/8 -inch and the tail end is somewhat pointed. Despite the name, bluegrass billbugs will feed and even thrive on most cool season turf species.

Damage - Look for evidence of damage along the edges of paved areas in mid- to late July. Bluegrass billbug infested areas begin to wilt but do not respond to watering. As larvae feed in the stems and on the roots, damaged turf can be tugged loose with very little force. Infested areas will brown out entirely in a matter of several days. Damage is usually most severe in July and August. Damaged turf often does not recover in September and renovation may be necessary.

Scouting - Larvae can be found by digging into the root/thatch interface with a hand trowel and inspecting the area. Accumulations of “sawdust-like” material (billbug excrement) will be found in the thatch.

Invasive craneflies


The European cranefly (Tipula paludosa) is an invasive species that has become a pest in western New York and southern Ontario (Niagara Peninsula). The common (or marsh) cranefly (Tipula oleracea) is another invasive species that has become established in western New York and Long Island. T. oleracea has been recently reported from several areas in Massachusetts, including Martha’s Vineyard, Cape Cod, and several suburbs south and west of Boston. Adults (which resemble large mosquitoes) emerge in late August or September. Females lay 200 to 300 black eggs near the soil surface. Small larvae feed from October through February, (when temperatures are mild). Larvae normally feed in the top inch of the soil, feeding on roots and root hairs. Larvae can be found within 3 inches of the surface, even in the winter months (larvae wriggle to the surface and can be seen projecting out of the turf. They pupate mid-March to mid-April. New adults emerge, lay eggs, and the resulting larvae feed through the summer months. They pupate in mid- to late-August, and adults emerge in September to complete the cycle.

Damage - Damage may resemble grub damage, especially in higher cut turf, because the larvae destroy roots. Animals and birds may cause turf damage while foraging for the larvae, as is also frequently the case with white grubs. On closely-mown turf, such as tees and greens, the damage might resemble cutworm feeding or aerification holes with the edges nibbled away.

Scouting - Watch for flights of ‘large mosquitoes’ in the spring and late summer. For larvae, take a soil sample (a cup cutter plug to a depth of about six inches often works well) and break the soil apart. The larvae are olive green to dark brown and quite active, often within the top inch of soil or in the thatch. Larvae can occasionally be seen at the surface feeding on turfgrass foliage on warm, humid nights.

Ants


Ants can be beneficial because they are often predators of other insects.

Damage - Several species of ants occur in turf and can disrupt the surface when building mounds. The turfgrass ant (Lasius neoniger) forms numerous mounds of 0.5” to 2.0” diameter on closely mown turfgrass, such as golf course fairways. These mounds are unsightly and can dull or damage mower blades. In the process of building tunnels, ants can break off roots and root hairs or increase desiccation of the soil.

Scouting - Rough estimates of ant activity can be obtained by counting the number of mounds in a given area.

Insect threshold levels

The key to any Integrated Pest Management program is the identification of response (or “action”) threshold levels. There is no single magic number which will be appropriate for all turf situations. Thresholds are given as first approximations only, and should be used only as guides.

Several agronomic factors will have a direct effect on the number of insects a turf area can tolerate. Some of these factors include the species of turfgrass, the height of cut, availability of irrigation (and resulting soil moisture distribution), use patterns (including traffic and other sources of compaction), and the fertility program. The thresholds presented in Table 14 are for unirrigated turf and are provided as guidelines only. In most cases, irrigated turf can sustain higher insect populations without showing stress.

Actual response thresholds will depend on the overall vigor of the turf being managed, the use of the turf, the presence of secondary pests such as skunks and raccoons, and the quality expected.

Table 14. Approximate threshold levels* for turfgrass insect pests.

INSECT	Approximate threshold per sq. ft.
Japanese beetle	8 to 15 larvae
Oriental beetle	8 to 15 larvae
Masked chafer	8 to 15 larvae
European chafer	3 to 8 larvae
Asiatic garden beetle	12 to 20 larvae
May beetle (Phyllophaga)	2 to 4 larvae
Black turfgrass ataenius	15 to 80 larvae
Annual bluegrass weevil	10 to 80 larvae
Bluegrass billbug	No good estimate available
Chinch bug	30 to 50 nymphs
Sod webworm, cutworm	No good estimate available
* Please note that actual threshold levels will vary based on site conditions, management practices, and/or turf use.

 

Paenibacillus popilliae


Milky disease (sometimes called “milky spore”) is caused by a bacterium, Paenibacillus popilliae, which occurs naturally in soil and affects the digestive system of Japanese beetle grubs. According to tests conducted in New Jersey, there is no evidence that milky disease is effective against other species of grubs. It is relatively nontoxic to people and other “non-target” organisms.

Milky disease is somewhat inconsistent in the Northeast. More turf managers have reported success with milky spore in the sandy soils of southeastern Massachusetts than in other areas. In any case, the milky disease organism may take several months to become effective; in some cases it may remain effective for three to five years. The discovery of “milky looking” grubs while monitoring may indicate that a milky spore application has taken hold. However, sporadic natural infestations of milky disease do occur, so the mere presence of milky grubs does not necessarily indicate that an application will be effective or consistent. Studies conducted in Kentucky indicate that there is no evidence that commercial preparations of P. popilliae increase the incidence of milky disease significantly in field populations.

Bacillus thuringiensis (Bt)

Bacillus thuringiensis (Bt) is a bacterium that causes disease in several kinds of insects. Recently several new strains of Bt have been identified that are quite specific in the kinds of insects they attack. Because they are more specific, they can be used in a turf setting without disrupting some of the natural enemies, such as predator beetles and mites, which are present.

The strain which is effective against caterpillars (particularly cutworms and sod webworms) is known as the “kurstaki” strain, and is available commercially (some products are not registered for turf use, so check the label carefully before purchasing or using any formulations). The material is formulated to be applied to the turf with a hydraulic sprayer. As with several of the biological control agents currently available, Bt kurstaki is most effective when directed against small stages of caterpillars (less than 0.25” long). Bt kurstaki will not kill caterpillars immediately after exposure, but it will paralyze the gut and digestive system very quickly after the insect ingests the material, so feeding activity stops soon after exposure. Currently, there are no published field trials available reporting the effectiveness of Bt kurstaki for caterpillar control in turf.

A newer strain of Bt (japanensis, or ‘buibui’) appears very promising based on field trials targeting Oriental beetle and Japanese beetle grubs, but looks less effective against European chafers and Asiatic garden beetles. It must be applied when grubs are just beginning to hatch (usually early to mid-August). This strain is not currently under commercial development.

Beauveria bassiana


Beauveria bassiana is a fungus that occurs naturally in New England turfgrass, and is favored by wet conditions in the spring. The fungus is a natural enemy of chinchbugs. B. bassiana is sometimes available commercially, but no field trials have been conducted (and published) to determine whether commercial applications will reduce pest populations.

Entomopathogenic nematodes

Entomopathogenic nematodes are small, microscopic worms which attack insects. Certain species of these nematodes have proven to be quite effective against some of the surface feeding insects (cutworms, sod webworms). The preparations, consisting of live organisms, must be handled more carefully than traditional insecticides. For example, they are temperature-sensitive, so the containers must be stored in areas that will not get too hot (above 80° to 85°) and will not freeze.

Entomopathogenic nematodes can be applied through standard hydraulic sprayers (although very fine filters should be removed). However, these nematodes are very sensitive to desiccation. To maximize their effectiveness, nematodes should be applied in early morning or late afternoon (not between 10 a.m. and 2 p.m.) and should be watered in immediately. In addition, nematodes are most effective when the target insects are small.

There are several species of nematodes which are commercially available in the United States at this time. Steinernema carpocapsae is available as several trade names. Studies throughout the Northeast indicate that this species of nematode is not particularly effective against white grubs, but it can be effective against caterpillars in turf (sod webworms and cutworms). Many turf managers do not rely on nematodes for caterpillar control, however, because they tend to be inconsistent. If nematodes are used to target caterpillars, they must be applied when caterpillars are small (less than 0.25 inch long), and must be watered in with at least 0.25 inch water.

Several field studies have been conducted over the past five years, testing the effectiveness of entomopathogenic nematodes against annual bluegrass weevils (ABW). The results have been inconclusive — occasionally there appears to be a reduction in larval populations in the first generation, but the “window of opportunity” (when larvae are susceptible) appears to be about five to seven days each spring. The nematode showing the most promise is Steinernema carpocapsae, but more field testing must be completed before golf course superintendents can be confident using nematodes for ABW control.

Heterorhabditis bacteriophora (HB) is also available under many different trade names, and field trials in Massachusetts indicate that it can reduce white grub populations when used properly. However, studies conducted at Rutgers University indicate that HB is much more effective against Japanese beetle grubs than other species of grubs. When targeting grubs, nematodes must be applied when grubs are present but still small (often mid August to early September) and must be watered in with at least 0.25 inch of water.

Neem

Azadirachtin is a derivative of the neem tree, which grows in India and other tropical settings. The compound repels several kinds of insects and often causes them to stop feeding. Neem also acts as an insect growth regulator on some insects, preventing them from molting normally from one stage to the next. There is an indication that the neem compounds may sometimes reduce populations of the surface feeders (cutworms and sod webworms). Some commercial applicators report that applications of azadirachtin have been inconsistent. Also, some azadirachtin formulations are very viscous and difficult to handle in a sprayer.

Spinosad

Spinosad (Conserve) is a synthetic preparation of a soil actinomycete which is often categorized as a biological control material, even though it is synthetic and produced in large facilities. It has provided significant control of larval populations of annual bluegrass weevil in the first generation in several field trials. It must be applied as the larvae are emerging from the stems, before they reach their largest (fourth and fifth) instars. Spinosad is also very effective against caterpillars in both turf and landscape setings.

Beneficial insects in the turf setting

If a turf manager were to take a cup cutter sample from a turf area which had not been treated with insecticides for a year or two, and extracted all of the insects and other arthropods from that sample, that manager would be amazed at the diversity of arthropod life in the sample. There are countless beneficial insects and close cousins active in the thatch and upper root zone, decomposing organic matter or preying on other insects. Some of the predatory arthropods include ground beetles (most of which feed on insect eggs and small soft bodied insects, such as small caterpillars or aphids), predatory mites, spiders, and ants. Some of the decomposers include springtails (often in huge numbers), saprophytic nematodes, symphylans, and some mites. While we do not yet fully understand the role of each of these creatures, we do know that their role is crucial to thatch management, and to the overall health of the turf.

Unfortunately, some of the insecticides that are currently used in turf settings are “broad spectrum” materials, which means they kill a wide range of insects and other arthropods, including many beneficial insects. If these broad spectrum insecticides are used regularly, the balance of beneficial insects may change over time, so that fewer of the predators or decomposers remain active. As a result, pest populations can build up more rapidly following an application, because some of the natural enemies have been destroyed and are no longer available to provide a natural level of control of the target pest.

It is critical, therefore, that insecticide applications should be made only when sampling has demonstrated that a pest population has reached the threshold level, and only to areas for which infestation has been confirmed through careful monitoring.

Big-eyed bugs are naturally occurring predators that can be found in many New England turf settings. They are very effective predators of chinchbugs, but unfortunately they look very similar to chinchbugs (except for big bulging eyes), so sometimes insecticide applications are made that reduce big-eyed bug populations. These predators are not available commercially.

Endophytic turfgrass cultivars

Endophytic cultivars have within the seed and plant itself a beneficial fungus called an endophyte. The fungus is unable to live outside of the seed or plant, and so it depends upon the plant for its survival. The plant also benefits from its association with the fungus. Endophyte-enhanced cultivars tend to be vigorous even under conditions of stress such as minimal fertilization and irrigation, and exhibit a level of resistance to foliar feeding insects such as sod webworms, and in particular chinchbugs and billbugs. Endophytes impart no tolerance or resistance to root feeding insects such as white grubs. Furthermore, cultivars which contain endophytes may vary in their susceptibility or in their resistance to disease. This factor is not as clear cut as insect resistance, and will vary by cultivar as well as by disease.

At present there are some endophytic cultivars of perennial ryegrass, tall fescue, creeping red fescue, hard fescue and chewings fescue available. When repairing lawns and other areas that have been damaged by surface feeding insects such as chinchbugs, billbugs, or sod webworms, select endophytic cultivars of appropriate turfgrasses whenever possible. Keep in mind that the percent of endophyte infection in a cultivar may differ by seed lot. Also, the level of endophyte in old or improperly stored seed will decrease as the fungus loses viability. Check with a reputable seed supplier for cultivars with endophyte, as well as for level of endophyte in a particular seed lot.

Endophytic turfgrass cultivars should not be used where animals may graze. The alkaloids produced by the endophyte and the interaction of the endophyte with the plant not only impart some degree of insect resistance to the plant, but also have the potential to sicken animals that may feed upon the plant.

Some turf insecticides act very quickly while others take much longer to kill the target insect. In addition, some materials persist for several weeks and remain active, while others break down in a matter of a few days. Of the insecticides listed in these guidelines, a few work quite quickly (within one to three days) and break down within one to two weeks. These materials, often used for ‘curative’ applications, include: acephate (Orthene), and trichlorfon (Dylox). Some of the synthetic pyrethroids, like cyfluthrin (Tempo) and bifenthrin (Talstar) begin to act quickly but will persist longer if they penetrate the thatch and/or are applied to the soil.

Very few of the turf insecticides currently available for use in Massachusetts are intermediate in their “speed of efficacy” and persistence. These materials will often take three to seven days to begin to affect the target insects, but normally will remain active for three to five weeks, and sometimes even longer. Several “intermediate” materials have been taken off the market in the last few years, one that remains is carbaryl (Sevin).

Some insecticides, such as imidacloprid (Merit) or chlorantraniliprole (Acelepryn), are used for preventive insect control in areas that have a history of damage.  This use pattern is common for white grub management, but care must be taken to ensure that the material is in place and fully active when the grubs are in the most susceptible stage. These materials vary in how quickly they become active, but then normally remain active for several weeks or even months.
Please note that some listed materials have been somewhat inconsistent in their performance while others have provided similar levels of control through the years. Be sure to obtain current label information before using any insecticide.

Using insecticides preventively in an IPM program

Insecticides usually have either preventive or curative action against the pest for which they are used. Preventive materials are applied before a noticeable pest population develops. Curative materials are typically applied after populations reach a damaging level.

There are many components to an IPM program, including monitoring for pest activity, establishing tolerance levels, and considering cultural and biological management strategies whenever possible. One of the key tenets of IPM is to apply pesticides when a pest population exceeds a threshold level and only when all other avenues of control have been exhausted. In certain instances, however, preventive pesticide applications may be preferred to the alternative of waiting until a problem develops.  Part of the process in selecting and applying pesticides in an IPM program is to use application methods and materials that minimize the potential for environmental disruption.

For example, several turf insecticides [including the neonicotinoids and chlorantraniliprole (Acelepryn)] provide preventive protection against white grubs and are much less toxic than the older organophosphate materials that were used for many years. There are few cultural practices or effective biological control agents available that provide reliable control of white grub populations. Furthermore, in Massachusetts the use of the most effective curative material, trichlorfon (Dylox), is not allowed on school properties as specified in the Children and Families Protection Act (see the Pesticide Regulations section of this guide for more information). The only option for effective management of high populations of white grubs in this circumstance is preventive application with a neonicotinoid or chlorantraniliprole.

To be justified in an IPM plan, preventive insecticide applications must be based on scouting or other documentation of the potential for damaging populations from the previous season or seasons.

Insecticide resistance


There are several chemical classes of insecticides available to turf managers. Recently some turf insects (most notably, the annual bluegrass weevil) have developed resistance to certain chemical classes (in the case of the weevil, resistance to pyrethroids). This means that applications of certain products made now at rates that were effective several years ago do not kill as many insects. One of the most effective ways to delay the development of resistance is to avoid using insecticides in the same chemical class repeatedly. In most cases, you must also avoid using chemicals with the same mode of action. The Insecticide Resistance Action Committee (www.irac-online.org) has assigned “IRAC” numbers for each chemical class, and many chemical companies are putting these numbers on labels to make it easier for turf managers to incorporate this information into their decisions on chemical inventories. For example, any insecticide in the neonicotinoid class (e.g., Merit or Meridian or Arena) will have a black box with a white “4A” indicating the IRAC chemical subgroup. Carbamates (class 1A) and organophosphates (class 1B) are in the same group but listed separately because while the chemistry of the two classes of insecticides is different, the mode of action (cholinesterase inhibition) is the same.

The following information on insecticide characteristics will help turf managers avoid using the same chemical class repeatedly. Trade names referenced here are the first trade name under which the product was available in turf. Note that for some chemicals, there are many additional trade names not listed here.

Table 15. Characteristics of turf insecticides registered for use in Massachusetts.

ABW = annual bluegrass weevil; BTA = black turfgrass ataenius; ECF = European crane fly

Chemical class: ORGANOPHOSPHATE OR CARBAMATE			IRAC class: carbamate – 1A; organophosphate – 1B
Most are “older” chemicals and, as cholinesterase inhibitors, tend to be more acutely toxic to vertebrates than some of the newer compounds. There is a lot of variation in field characteristics: Some are soluble in water while others are not; some are systemic while some are not; some are quite persistent while some are not. For example, trichlorfon (Dylox) and acephate (Orthene) are very soluble in water and can break down quickly when water pH is above 7.5. Neither is very persistent in field conditions. Most other insecticides in these classes are being phased out of the turf market.
Common name	Trade name	Partial list of insects on label		Notes
acephate	Orthene	caterpillars, chinchbugs
carbaryl	Sevin	caterpillars, many beetle adults, chinchbugs, ECF		Very toxic to honeybees and other bees
chlorpyrifos	Dursban	billbug adults, caterpillars, chinchbugs, ECF		Golf course only. Actively being phased out of the market and available only as generic formulations.
trichlorfon	Dylox	white grubs		Works quickly, breaks down quickly. Susceptible to rapid breakdown with water pH above 7.0-7.2
Chemical class: PYRETHROID			IRAC class: 3
Every pyrethroid available for use on turf is virtually insoluble in water and is bound quickly to organic matter. As a result, pyrethroids are effective against insects that are active in the thatch (e.g., annual bluegrass weevil adults, black turfgrass ataenius adults, bluegrass billbug adults, caterpillars, chinchbugs, European crane fly). ABW has developed resistance to pyrethroids in some locations, particularly between Hartford, CT and metropolitan NY. Most pyrethroids begin working three to five days after application (sometimes more quickly) and remain active for three to five weeks (sometimes longer). Labels on pyrethroids sometimes change, and there may be additional products labeled for turf that are not listed here. Most pyrethroids are toxic to fish and aquatic invertebrates, and some are also toxic to bees that are exposed to direct treatments on flowering crops and weeds. Some of the pyrethroids that are used in New England are listed below. Many pyrethroids have gone “off patent” so there are many other products available with different trade names.
Common name	Trade name	Partial list of insects on label		Notes
bifenthrin	Talstar	ants, ABW adults, BTA adults, billbugs, caterpillars, chinchbugs, ECF
cyfluthrin	Tempo	ants, ABW adults, BTA adults, billbugs, caterpillars, chinchbugs, ECF
lambda-cyhalothrin	Scimitar	ants, ABW adults, BTA adults, billbugs, caterpillars, chinchbugs, ECF
deltamethrin	Deltagard	ants, ABW adults, BTA adults, billbugs, caterpillars, chinchbugs, ECF
Chemical class: NEONICOTINOID			IRAC class: 4A
There are four neonicotinoids currently available in turf, and all of them are systemic through the roots.  Imidacloprid works much more slowly than most of the other insecticides available for turf. However, it appears to remain active for several weeks, and even a few months in some cases. Two of the neonicotinoids (chlothianidin and thiamethoxam) are also absorbed directly into leaf tissue to some degree. As a result they tend to work a little more quickly than imidacloprid and appear to be active on a slightly wider range of turf insects. None of the neonicotinoids are effective against Asiatic garden beetles. Neonicotinoids often take several days to start working, but remain active for several weeks or months (depending on the time of year they are applied). Even though imidacloprid has been on the turf market for more than 10 years, there have been no reports of resistance in any turf insects yet. There have been some implications that use of imidacloprid might be a contributing factor to colony collapse disorder in honeybees, but there are also many other possible explanations for that disorder. Care should be taken when using any neonicotinoid to avoid applications when honeybees are foraging, such as when clover or ground ivy is in bloom. In addition, some labels indicate products are toxic to aquatic invertebrates.
Common name	Trade name	Partial list of insects on label		Notes
chlothianidin	Arena	ABW, BTA, caterpillars, billbugs, white grubs
dinotefuran	Zylam			More soluble than the others, optimum use patterns still being identified. Dinotefuran is regulated under the Public Drinking Water Supply Protection Regulations in MA, see the Pesticide Regulations section of this guide for details.
imidacloprid	Merit	ABW, BTA, billbugs, white grubs		Merit went “off patent” in 2007
thiamethoxam	Meridian	ABW, BTA, caterpillars, billbugs, white grubs		Thiamethoxam is regulated under the Public Drinking Water Supply Protection Regulations in MA, see the Pesticide Regulations section of this guide for details.
Chemical class: COMBINATION PRODUCTS			IRAC class: neonicotinoid, 4A; pyrethroid, 3
Three products are now available for commercial applicators that combine a neonicotinoid and a pyrethroid. The combination provides protection against soil insects (neonicotinoid) and surface feeders (pyrethroid). Optimal timing of application depends on what the primary insect target is at a given site. (For example, if white grubs are the primary target, applications should be made just as adults become active and start laying eggs. If billbugs are the primary target, applications could be made in late May or early June to target adults as they become active.)
Trade name	Contents	Partial list of insects on label		Notes
Allectus	Merit and Talstar	ABW, BTA, billbugs, caterpillars, chinchbugs, ECF, European chafer, Japanese beetle, and oriental beetle.		available only to commercial applicators
Aloft	Proprietary blend of chlothianidin and bifenthrin	ABW, BTA, billbugs, caterpillars, chinchbugs, ECF, European chafer, Japanese beetle, and oriental beetle.		available only to commercial applicators
Maxide	Meridian and Scimitar	ABW, BTA, billbugs, caterpillars, chinchbugs, ECF, European chafer, Japanese beetle, and oriental beetle.		available for general use
Other generic combination products are also available.
Chemical class: OXADIAZINE			IRAC class: 22
There is only one product currently available in turf that is in the oxadiazine class: indoxacarb. This class has a very low mammalian toxicity and a new mode of action. It works by blocking the movement of sodium ions into nerve cells. Product labels have the same precautionary language as pyrethroids regarding toxicity to fish and aquatic invertebrates, as well as foraging honeybees. Indoxacarb is particularly effective against caterpillars and is most effective when applications are made targeting eggs and small caterpillars.
Common name	Trade name	Partial list of insects on label		Notes
indoxacarb	Provaunt	ABW larvae, caterpillars
indoxacarb	Advion	turfgrass ants (bait formulation)
Chemical class: ANTHRANILIC DIAMIDE			IRAC class: 28
This new chemical class has a totally new mode of action and has such low mammalian toxicity, the EPA did not require the registrant to include a signal word on the label. It received federal registration in April 2008 and at least one formulation has been registered in each of the New England states. The label describes chlorantraniliprole as toxic to aquatic invertebrates, but it is relatively insoluble so it is less likely to move to surface water than some other products. It is not toxic to bees, ants, or wasps. It is extremely effective against all the white grub species we encounter in New England, but should be applied before early to mid June to achieve maximum effectiveness against grubs. Spring applications of chlorantraniliprole will not affect grubs that are present in the spring.
Common Name	Trade name	Partial list of insects on label		Notes
chlorantraniliprole	Acelepryn	ABW, BTA, billbugs, caterpillars, white grubs
Chemical class: SPINOSYN			IRAC class: 5
This group is represented by spinosad (Conserve), which is derived from a soil actinomycete. The label describes it as highly toxic to bees and to mollusks. Effective against many caterpillars, including sod webworms, cutworms, and armyworms (as well as caterpillars in the landscape). Also a good larvacide for annual bluegrass weevil.
Common name	Trade name	Partial list of insects on label		Notes
spinosad	Conserve	ABW larvae, caterpillars		Apply against ABW larvae when larvae have just begun to emerge from the stem

 

Table 16: Labeled insecticides and ideal application timing for common turf insect pests in New England.

Insect	Insecticide	Ideal Timing	Comments
White grubs (Japanese beetle, European chafer, Oriental beetle, Asiatic garden beetle, etc.)	carbaryl (Sevin)	when grubs are present	Sometimes inconsistent, sensitive to high pH. Very toxic to honey bees. Not available for use on school grounds in Massachusetts.
	chlothianidin (Arena)	when adults are laying eggs	A neonicotinoid, not effective against Asiatic garden beetle (AGB). May have some curative properties in late summer applications.
	chlorantraniliprole (Acelepryn)	mid April to early June	Not effective against grubs present in spring.
	imidacloprid (Merit)	when adults are laying eggs	Merit went off patent in 2007, many generic forms now available. A neonicotinoid, not effective against AGB. Not effective against grubs present in spring
	thiamethoxam (Meridian)	when adults are laying eggs	A neonicotinoid, not effective against AGB
	trichlorfon (Dylox)	when grubs are present	Best option to control grubs in spring. Can be used into mid September most years. Sensitive to high pH. Not available for use on school grounds in Massachusetts.
	Allectus	when adults are laying eggs	combination product – Merit + Talstar (not effective against AGB)
	Aloft	when adults are laying eggs	combination product – proprietary blend of chlothianidin and bifenthrin (not effective against AGB). May have some curative properties in late summer applications.
	Maxide	when adults are laying eggs	combination product – Meridian + Scimitar (not effective against AGB)
Scouting: Scout for adult activity in mid-July to mid-August by scouting nearby foliage and/or use black light traps for European chafers. Scout for larvae in late summer or early spring with soil samples. Check the root/thatch interface for presence of grubs in late July to late August. Treatment: Treat when adults are laying eggs (mid-June to early August) if using a neonicotinoid. Treat between mid-August and mid-September to moist soil if grub population averages at least 5 to 10 grubs per square foot if using an intermediate or fast-acting material. Water in (at least 0.25”) immediately after application, but avoid puddling. If population was not controlled in late summer, apply spring control as soon as grubs are near surface (normally in April). Note that some materials have been inconsistent while others have performed consistently well over the years.
Insect	Insecticide	Ideal Timing	Comments
Annual bluegrass weevil (Hyperodes weevil)	bifenthrin (Talstar)	Forsythia half green, half gold to dogwood full bloom
	chlorantraniliprole (Acelepryn)	Two weeks after Forsythia half green, half gold	Also controls white grubs and caterpillars
	chlorpyrifos (Dursban)	Forsythia half green, half gold	Golf course use only. Generic formulations only.
	cyfluthrin (Tempo)	Forsythia half green, half gold to dogwood full bloom
	lambda-cyhalothrin (Battle, Scimitar)	Forsythia half green, half gold to dogwood full bloom
	deltamethrin (Deltagard)	Forsythia half green, half gold to dogwood full bloom
	indoxacarb (Provaunt)	when larvae first emerge (Rhododendron catawbiense full bloom)	May need to make two applications. Also effective against caterpillars.
	spinosad (Conserve)	when small larvae present (Rhododendron catawbiense full bloom)
	trichlorfon (Dylox)	when small larvae present (Rhododendron catawbiense full bloom)
Scouting: Scout for adult activity in mid- to late April with soapy flush. Monitor for larval activity in late May through June with soil samples, flotation, and visual inspection of thatch layer or collect samples, submerge in saline solution. Treatment: When targeting adults, treat between Forsythia and flowering dogwood “full bloom” (usually late April to mid-May). Treat for second generation if necessary during first two weeks of July. Water lightly (0.05” to 0.1”). Most applications are best targeted against adults as they begin to lay eggs or against young larvae. When targeting larvae, treat at Rhododendron catawbiense full bloom. Many annual bluegrass weevil (ABW) populations in the Northeast have developed resistance to pyrethroids. While not every population is resistant, golf course superintendents should try to minimize their reliance on pyrethroids whenever possible. Cultural strategies that may help reduce larval populations or minimize damage include converting Poa annua to creeping bentgrass, raising the height of cut where possible, and removing pine litter from nearby white pines. Monitor the areas where ABW are active and target larvae with one of the larval treatments as soon as they are observed.
Insect	Insecticide	Ideal Timing	Comments
Black turfgrass ataenius adults	bifenthrin (Talstar)	Forsythia half green, half gold to dogwood full bloom
	chlorpyrifos (Dursban)	Forsythia half green, half gold to dogwood full bloom	Golf course use only. Generic formulations only.
	cyfluthrin (Tempo)	Forsythia half green, half gold to dogwood full bloom
	lambda-cyhalothrin (Battle, Scimitar)	Forsythia half green, half gold to dogwood full bloom
	deltamethrin (Deltagard)	Forsythia half green, half gold to dogwood full bloom
Black turfgrass ataenius grubs	chlothianidin (Arena)	mid May to early June
	imidacloprid (Merit)	mid May to early June
	thiamethoxam (Meridian)	mid May to early June
	trichlorfon (Dylox)	when larvae present (often late June)
	Allectus	late April to early June	combination product – Merit + Talstar
	Aloft	late April to early June	combination product – Arena + generic bifenthrin
Scouting: Look for adults, sometimes in very large numbers, on putting greens in April (or use a soapy flush to force them to the surface). Large numbers of adults do not necessarily lead to heavy grub populations. Monitor for grubs from mid-May through mid-August by soil sampling. Treatment: If treating for adults (before egg laying), apply Dursban or a pyrethroid between Forsythia full bloom and dogwood full bloom, (late April to mid-May) and again two weeks later. Water in lightly (0.05” to 0.1”). Use this approach only in areas where BTA populations have been unusually high in previous years, to avoid treating areas that do not have populations high enough to warrant control. If treating for larvae, apply a material which will penetrate the thatch when horse chestnut or Van Houette spirea are in full bloom, (usually early June). Water in with at least 0.15” to 0.3” of water immediately after application. Imidacloprid or chlothianidin can be applied preventively, but should not be applied earlier than early June if white grubs are also a problem.
Insect	Insecticide	Ideal Timing	Comments
Chinch bug	bifenthrin (Talstar)	June - July
	chlorpyrifos (Dursban)	June - July	Golf course use only. Generic formulations only
	cyfluthrin (Tempo)	June - July
	lambda-cyhalothrin (Battle, Scimitar)	June - July
	deltamethrin (Deltagard)	June - July
	Allectus	June to mid July	combination product – Merit + Talstar
	Aloft	June to mid July	combination product – Arena + generic bifenthrin
	Maxide	June to mid July	combination product – Meridian + Scimitar
Scouting: Scout for adult activity in May and early June, for immature stages throughout summer. In addition, chinch bugs move steadily in the thatch and can be seen by using fingers to spread the turf. Treatment: Populations are commonly highest in fine fescues and turf stands with thick thatch. Use endophyte containing cultivars when available; avoid drought conditions. Apply in June; water in lightly (less than 0.1”) after application. In some cases, a second application two to three weeks later may be needed.
Insect	Insecticide	Ideal Timing	Comments
Cutworm	bifenthrin (Talstar)	when damage appears
	carbaryl (Sevin)	when damage appears	Very toxic to honey bees. Not available for use on school grounds in Massachusetts. Repeat applications may be needed, especially after heavy rain.
	chlorantraniliprole (Acelepryn)	mid May to mid June	Several weeks of protection when applied at high label rate.
	chlorpyrifos (Dursban)	when damage appears	Golf course only. Generic formulations only.
	cyfluthrin (Tempo)	when damage appears
	deltamethrin (Deltagard)	when damage appears
	indoxacarb (Provaunt)	June – July	Often provides several weeks protection.
	lambda-cyhalothrin (Battle, Scimitar)	when damage appears
	Spinosad (Conserve)	when damage appears
	Allectus	June to mid July	combination product – Merit + Talstar
	Aloft	June to mid July	combination product – proprietary blend of chlothianidin and bifenthrin.
	Maxide	June – July	combination product – Meridian + Scimitar
Scouting: Monitor adult activity with black light traps. Apply insecticides two to three weeks after peak flights. Scout for caterpillars (late in the day or early in the morning) with soapy flushes. Treatment: Most cutworms are nocturnal, so treatments are most effective if applied late in the day. Water lightly (less than 0.10”). On golf courses inspect aerification holes throughout summer. Damage often becomes most noticeable shortly after aerification, particularly in late summer. Apply two to three weeks after peak moth flight.
Insect	Insecticide	Ideal Timing	Comments
Sod webworm	bifenthrin (Talstar)	when damage appears
	carbaryl (Sevin)	when damage appears	Very toxic to honey bees. Repeat applications may be needed, especially after heavy rain. Not available for use on school grounds in Massachusetts.
	chlorantraniliprole (Acelepryn)	mid May to mid June	Several weeks of protection when applied at high label rate.
	chlorpyrifos (Dursban)	when damage appears	Golf course use only. Generic formulations only.
	cyfluthrin (Tempo)	when damage appears
	lambda-cyhalothrin (Battle, Scimitar)	when damage appears
	deltamethrin (Deltagard)	when damage appears
	indoxacarb (Provaunt)	June – July
	Spinosad (Conserve)	June – July
	Allectus	June – July	combination product – Merit + Talstar
	Aloft	June – July	combination product – proprietary blend of chlothianindin and bifenthrin
	Maxide	June – July	combination product – Meridian + Scimitar
Scouting: Monitor adult activity by inspecting turf surface at twilight looking for small “tube moths” flitting just above the canopy. Scout for caterpillars with soapy flushes. Treatment: Check for sod webworm activity: look for small green pellets in upper thatch or flush an area with soapy water. Watch for webworm moths flying at twilight. Apply controls 10 to 14 days after number of moths declines sharply. Repeat applications may be necessary. Treat as late in day as possible. Water lightly (0.10”); do not mow for one to three days after application.
Insect	Insecticide	Ideal Timing	Comments
Invasive craneflies, preventive	bifenthrin (Talstar)	mid September to mid October	Apply when larvae are mostly first and second instars.
	carbaryl (Sevin)	mid September to mid October	Very toxic to honey bees. Apply when larvae are mostly first and second instars. Not available for use on school grounds in Massachusetts.
	chlorantraniliprole (Acelepryn)	mid September to mid October	Preliminary trials look promising.
	chlothianidin (Arena)	mid September to mid October	Apply when larvae are mostly first and second instars.
	indoxacarb (Provaunt)	mid September to mid October	Apply when larvae are mostly first and second instars.
	Aloft	mid September to mid October	combination product – proprietary blend of chlothianidin and bifenthrin
Invasive craneflies, curative	chlothianidin (Arena)	when larvae are small	Apply when larvae are mostly third instars.
	indoxacarb (Provaunt)	when larvae are small	Apply when larvae are feeding actively in spring.
	Aloft	when larvae are small	combination product – proprietary blend of chlothianidin and bifenthrin
Scouting: “Common” cranefly (Tipula oleracea) larvae occasionally can be seen at the surface feeding on foliage on warm, humid nights. Check for larval activity by taking soil samples (cup cutter plugs), dislodging the soil and looking for the dark-colored larvae. In late summer look for pupal skins that jut out from the surface. Also watch for adults flying just above the turf surface or landing on walls of buildings. Treatment: Normally the larvae survive best in areas that have high soil moisture during the fall and spring. Withholding irrigation during the time when females are laying eggs may reduce larval survival. There are two approaches for controlling cranefly larvae. Preventive applications are made when larvae are first and second instars (usually mid September to mid October), while curative applications are made when larvae are third and fourth instars (usually mid March to mid April). Water lightly to moderately (0.05 to 0.15 inch) to move product into the thatch and enhance contact with the larvae. A second generation occurs with egg laying in April or May and larvae feeding from mid May through late August.
Insect	Insecticide	Ideal Timing	Comments
Turfgrass ants (Lasius neoniger)	bifenthrin (Talstar)	when new mounds appear
	chlothianidin (Arena)	when new mounds appear	Studies in other states indicate spring applications can provide control for several weeks
	chlorpyrifos (Dursban)	when new mounds appear	Golf course use only. Generic formulations only.
	cyfluthrin (Tempo)	when new mounds appear
	lambda-cyhalothrin (Battle, Scimitar)	when new mounds appear
	deltamethrin (Deltagard)	when new mounds appear
	hydramethylnon (Maxforce)	when new mounds appear	Bait – do not water in
	imidacloprid (Merit)	when new mounds appear	Studies in other states indicate spring applications can provide control for several weeks
	indoxacarb (Advion)	when new mounds appear	Bait – do not water in
	Aloft	when new mounds appear or in mid to late August	combination product – proprietary blend of chlothianidin and bifenthrin. Bifenthrin provides quick relief, chlothianidin provides longer coverage
Scouting: Scout for turfgrass ants by watching for new mounds on the surface. Treatment: Turfgrass ants produce mounds on turf that are unsightly and can dull mower blades. The traditional approach has been to apply a pyrethroid or chlorpyrifos to the new mounds as soon as they appear (typically late April or early May). These surface applications kill many of the workers and weaken the colony but the only way to eliminate a colony is to kill the queen. The most effective way to eliminate the queen is to use a bait formulation, which workers will carry to the brood chamber. Baits should not be watered in, while surface applications can be watered in lightly (less than 0.10 inch).

 

Table 17. Insect treatment calendar.

Insect treatment		Mar				Apr				May				Jun				Jul				Aug				Sep				Oct
One year grubs: Japanese beetle, European chafer, masked chafer, Oriental beetle, Asiatic garden beetle
2 or 3 year grubs: May or June beetles. Best time is July of year the eggs are laid. Second best time is spring after eggs are laid.
Hyperodes weevil
Black turfgrass ataenius (adult)
Black turfgrass ataenius (larvae)
Chinch bugs
Billbugs
Sod webworms
Cutworms
Ants
periods where damage is most likely to occur   best time to treat (specific timing depends upon material selection)   second best time to treat (specific timing depends upon material selection)