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Commonly Encountered Invertebrate Lawn and Garden Pests

by Bruce Wenning

There are many garden pests out there, but this paper describes several of the more commonly encountered pests in the garden and provides information about options for control.

Below the Ground Invertebrate Pests

Common name: white grubs

Order: Coleoptera (beetles)

Family: Scarabaeidae

A variation of this section was originally published in the Newton TAB (Newton, Massachusetts) in 2006 by the author.

White grubs are insect pests of home lawns, athletic fields, parks, gardens and anywhere their preferred hosts grow. They live in soil; are C-shaped, have six legs, white colored bodies, and chewing mouthparts; and feed on turf grass roots and the roots of other plants including some woody plant species. Lawns that are attacked by these pests show poor vigor (yellowing of turf grass blades), thin turf, smaller (or no) roots and bare spots susceptible to weed colonization.

The four white grub species of concern in our area are introduced pests. When in high numbers, they can be are very problematic on home lawns. White grubs are the larval or immature stage of beetles and, as stated above, are in the insect order, Coleoptera. They are Japanese beetle, Popillia japonica; Oriental beetle, Anomala orientalis; European chafer, Rhizotrogus majalis; and Asiatic garden beetle, Maladera castanea.

The life cycle for all four species is very similar: there is one generation per year, adult beetles are active during the summer feeding and mating. The grub (larval stage) is actively feeding underground on turf grass roots in the fall (August through October) and again in the spring (April through May). It is too often assumed that all white grubs are the insecticide susceptible Japanese beetles. They are not! And particularly, as there are health concerns and environmental problems associated with the misuse and overuse of insecticides for the control of white grubs, it is very important to properly identify white grubs using a 10X hand lens or dissecting microscope, so that the least environmentally toxic control agents can be used. See figure 1.

Figure 1. Diagram shows where to look for raster on any white grub. Source: www.ag.umass.edu

Unfortunately, many landscape company personnel typically do not identify these specific grubs to species, and thereby mistakenly assume all are the same single species they are familiar with.

Therefore, the following grub descriptions with accompanying illustrations should help you to properly identify the white grub encountered to species so you can match the species identified to threshold levels for site specific control measures at the time of identification. See figure 2.

Figure 2. White grub rastral patterns of lawn-infesting white grubs. Source: www. ag.umass.edu

The Japanese beetle grub has a small distinctive V-shaped rastral (spines)pattern, and a transverse anal slit on the 10th abdominal segment. These grubs are widely distributed in southern New England and are more susceptible (than the other species of white grubs) to chemical and nonchemical controls. Adult Japanese beetles feed on nearly 300 species of plants, including trees, shrubs and vines (see figure 3). The approximate threshold level per square foot is between 8 and 15 grubs (Lanier and Owen, 2015)

Figure 3. Adult Japanese Beetle. Adults have been documented to feed on close to 300 plant species. Source: www.colorado.gov

The Oriental beetle grub has a transverse anal slit (like the Japanese beetle) but exhibits a unique straight and parallel rastral pattern. It is less susceptible to commonly used insecticides because it is quick to burrow down deeper into the soil during hot weather, where it is difficult to control. The approximate threshold level is also 8 to 15 grubs per square foot (Lanier and Owen, 2015).

The European chafer has a rastral pattern that is somewhat Y-shaped; rows of rastral spines look like an opening zipper near the anal slit. It is the most damaging to home lawns, causing turf to become easily dislodged from the soil. Sometimes called an “eating machine on lawn roots,” it’s the only grub that can feed during cold weather, causing root damage in the early spring and well into the fall, when the other grub species are inactive. It has even been detected feeding on lawn roots under snow in February. These grubs are hard to control with insecticides because they are larger in size than the other species, and they have genetic characteristics that enable them to metabolize some insecticides or behaviorally avoid them for an extended period of time. The approximate threshold level is lower in number than for the other grub species and is between 3 to 8 grubs per square foot (Lanier and Owen, 2015).

The Asiatic garden beetle has a rastral pattern in the shape of a reduced semicircle. Imidacloprid (trade name, Merit) has been and still is used for chemical control, but it has limited effectiveness. It is suspected that the spread of AGB is due to imidacloprid overuse: the chemical kills the other grub species and allows the expansion of this one. The approximate threshold level for this grub species is between 12 and 20 grubs per square foot (Lanier and Owen, 2015).

White grubs are beetles and undergo complete metamorphosis which means there is a pupal stage in their life cycle. Figure 4 illustrates the differences between complete and incomplete (gradual) metamorphosis. There is a pupal stage in the complete metamorphosis life cycle of beetles.

Figure 4. The top of this illustration shows complete metamorphosis for a beetle. Note the pupa. The bottom illustrates incomplete metamorphosis for a true bug. Note that there is no pupa. Nymphs and adults feed on the same plant at the same time.

How to Sample for White Grubs

The easiest and most accurate way to sample for white grubs is to make three one-foot square diggings: one on the edge of the damaged area, one in an area where turf is thick and green and one in a thinning area of turf. With a shovel, cut three sides of a square dig leaving one side alone to act as a hinge. Then pull back with your hand the three-sided dug turf square exposing the soil. Take a trowel and gently hit the soil separating it from the turf roots. Grubs, if present, will fall into the hole. Count them for each digging and be sure to properly identify each one to make your best decision about control options.

Biological and Chemical Control Options

Fortunately, there is a biological control alternative to synthetic insecticide that can reduce the need for chemical control of white grubs. Although there is one commercially available type of nematode, Steinernema carpocapsae, that does not provide white grub control, another commercially available nematode, Heterorhabditis bacteriophora (HB), has been shown by Dr. Albrecht Koppenhoffer (Rutgers University) to be an effective bio-control agent against Japanese beetle grubs.

Dr. Patricia Vittum (University of Massachusetts) has demonstrated satisfactory control for all four species of white grubs using the HB nematode in late summer field trials, but the trials were limited in scope.

IPM Labs entomologist Carol Glenister notes that HB nematodes are most effective when the soil is warm in late summer (mid-August to early September) and the grubs are larger in size. She does not recommend applying nematodes before then. She said that with the proper environmental conditions, nematodes will reduce all grub species to varying degrees.

The HB nematode seeks out grubs for food and reproduction. When this nematode enters a white grub through a natural body opening, it releases a bacterium while it feeds on the grubs’ internal organs, and this eventually kills the grub. The nematodes then move through the soil to seek out more grubs.

The EPA exempts nematodes from the registration required for chemicals, and protective equipment is not needed to apply them. Commercially available nematodes are specific to pests stated on the label. Read and follow all label instructions and be certain that the beneficial nematode matches the biology of the pest in question. To learn more contact: IPM LABS, Locke, N.Y. 315-497-2063, www.ipmlabs.com.

There are several chemical insecticides for white grub control. Choose the least toxic if possible.

Above the Ground Invertebrate Pests

Common name: hairy chinch bug

Order: Hemiptera (the true bugs)

Family: Lygaeidae

Subfamily: Blissinae

The hairy chinch bug (Blissus leucopterus hirtus) is the “chinch bug pest” of turfgrasses in New England. They are surface feeders that use their piercing-sucking mouthparts to suck sap from turfgrass crowns, stems and blades. They do not feed on roots like white grubs. Hairy chinch bugs tend to group or aggregate when feeding causing irregular patches of turfgrass to turn yellow and then brown killing the grass. Several connecting brown patches alarm the homeowner, who frequently and mistakenly, blame white grubs for the damage (Vittum, Villani and Tashiro, 1999; Olkowski, Daar and Olkowski, 1991)

Nymphs just hatched from eggs are the size of a pencil dot. There are five nymphal instars (growth stages) before the nymph transitions into the adult stage where they average a size of 1/6 of an inch (Cranshaw, 2004). Chinch bugs undergo gradual or incomplete metamorphosis which means there is no pupal stage (see figure 4). Wings of the adults are mostly a shiny white color, held flat over the body at rest. The body is black with legs ranging from red to yellowish red; there is a black triangular spot near the wing margin (top of the thorax) (Vittum et al,1999: Ellis and Bradley, 1992).

Damage is caused by both nymphs and adults (i.e., gradual metamorphosis) and is usually localized in sunny areas and mainly occurs during July and August. However, damage frequently goes unnoticed because it is commonly mistaken for summer dormancy or drought stress. When rains return in late summer, the turf killed by this pest does not recover while the surrounding uninjured turf greens up and grows (Vittum et al, 1999). It is for this reason that I call the hairy chinch bug the sneaky lawn pest. By the time you notice that your lawn has been killed, it’s too late to stop it.

How to Sample for Chinch Bugs

Monitoring your lawn weekly starting in late June will give you an edge over these “sneaky” insects. Several monitoring methods exist and are easy to do. One method is to take an empty two-pound coffee can with both ends removed and insert one end into the turf/soil interface so that it resembles a hollow post. Fill this post or cylinder with water just below the top so that it does not overflow (Vittum et al, 1999). Let it sit for 10 to 15 minutes and count the chinch bugs that have floated to the surface. This method prevents any floating insects from escaping because they are confined to the can. A second method involves taking a golf course cup cutter to cut (remove) a turf plug from your lawn and place in a bucket of water for 10 to 15 minutes and see if any chinch bugs have floated to the surface. When they float up, count the adults and nymphs; other insects will be included in the sample (Vittum et al, 1999).

UMass Extension estimates that 30 to 50 chinch bugs per square foot of healthy, well maintained turf is the threshold to begin chemical controls (Lanier and Owen, 2015). Threshold or tolerance level is better referred to as how many chinch bugs are considered too many before turf damage begins without control measures. Turf or lawn use, turf grass species present, turf vigor and condition, rate of chinch bug increase are some of the main biological and site characteristics considered in contributing to chinch bug threshold levels (Schumann, Vittum, Elliott and Cobb, 2002).

Nymphs feed longer and more steadily than adults. Smaller lawn areas attacked by this pest eventually begin to merge and present a larger damaged area exhibiting yellow-brown colored (injured) turf grass areas of noticeable concern (Vittum et al, 1999).

Chinch bug nymphs can be as small as a pencil dot right after hatching. There are five nymphal instars (growth stages) before the nymph transitions into an adult. Adults are 1/6 of an inch long (Cranshaw, 2004).

Adults have wings that are mostly a shiny white color held flat over the body at rest; body is black with leg color ranging from red to yellowish red. There is a black triangular spot on top of the thorax region (Vittum et al, 1999; Ellis and Bradley, 1992).

Common name: Aphids

Order: Homoptera (aphids, scales, hoppers, psyllids, and cicadas)

Family: Aphididae

Cranshaw (2004), states that there are over 1,300 species of aphids in North America where many are pests on woody and herbaceous plants of economic concern to landscape professionals.

Aphids are pear-shaped, small, soft-bodied insects ranging in size from 1/32 to 1/8 of an inch in length. Most adults have a pair of dorsal (top) protruding tube-like extensions called cornicles, which function to secrete defense chemicals (Borror, Triplehorn and Johnson, 1989; Gill, Clement and Dutky, 1999).

Body coloration ranges from black, red, green, brownish or gray depending on the species. Aphids can range in color within a species and between species (Gill et al, 1999).

Aphids can feed causing plant damage ranging from stunted growth, leaf curing/puckering; leaf yellowing and the production of a sticky waste substance called honeydew. Aphids, with their piercing-sucking mouthparts feed on plant sap in the phloem. The production of honeydew is the digestive excess sap secreted from the anus, not the cornicles. When the clear and sticky honeydew is colonized by the sooty mold spores, it eventually turns black colored becoming another telltale sign of homopteran feeding.

According to Cranshaw (2004), aphids reproduce asexually (i.e. without male fertilization) and this type of reproduction is called parthenogenesis or the reproduction without mating (Gill et al, 1992).

Therefore, adult females give birth to live young (nymphs). See figure 5. There are four nymphal instars before transitioning to the adult stage. Aphids undergo incomplete or gradual metamorphosis where there is no pupal stage as there is for insects undergoing complete metamorphosis.

Figure 5. During the growing season, aphids give birth to live young.

Sexual reproduction (female mates with a male) occurs only to produce overwintering eggs in the fall which are laid on a perennial plant and hatch the following spring (Cranshaw, 2004).

Aphids have complex life cycles involving the production of live young; winged and wingless forms; egg production and alternate plant hosts. This complexity is their adaptation to stressful population and environmental conditions to ensure that they pass on their genes to the next generation of aphids.

Aphid populations can be controlled safely by applying light weight horticultural oil or insecticidal soap according to label instructions every five to seven days for three weeks. Inspect for their presence on stems, under leaves and on buds.

Common name: Scale insects

Order: Homoptera

Family: Coccidae (the soft scales)

There are many species of soft scales and some have great economic importance as being pests on landscape plants both woody and herbaceous. Most are oval, flat to hemispherical in shape and range in color from white to dark brown to yellowish to light brown. Scales have complex life cycles like aphids. Textbooks illustrate their life cycle complexities.

Soft scales produce honeydew and attract sooty mold because, like aphids, they are phloem sap feeders (Cranshaw, 2004).

Figure 6. Brown colored hemispherical scale.

The very noticeable hemispherical scale (Saisettia coffee) is a common houseplant pest and looks like a brown round bump on gardenia, croton, ficus, euphorbia, schefflera, and many other species (Cranshaw, 2004). See figure 6. The cottony maple scale (Pulvinaria innumerabilis) feeds on maple and other tree species. The nymphs are leaf feeders and the adult scale feeds on branches and twigs (Cranshaw, 2004).

There are many soft scale pest species. When populations build up, plant symptoms are expressed as reduced plant vigor, stunting, leaf yellowing, premature leaf drop and dieback (Cranshaw, 2004).

Family: Diaspididae (the armored or hard scales)

The armored or hard scales differ from the soft scale group in adult scale cover attachment. The adult hard scale covering is separate from the underlying soft body. This family has more than 300 North American species with many important economic pest species including the oyster shell scale (Lepidosaphes ulmi) which feeds on many landscape tree and shrub species such as cotoneaster, dogwood, lilac, maple, and many more. It’s a branch, twig and trunk feeder (Cranshaw, 2004; Ellis and Bradley, 1992).

Figure 7. The very noticeable, white colored euonymus scale.

Pine needle scale (Chionaspis pinifoliae), camellia scale (L. beckii), euonymus scale (Unaspis euonymi) (see figure 7) and the elongated hemlock scale (Fiornia externa) (see figure 8) are just a few of the pest scales in this group (Johnson and Lyon, 1991; Cranshaw, 2004).

For additional information about the elongated hemlock scale visit the following website, https://extension.psu.edu/elongate-hemlock-scale

Figure 8. The elongated hemlock scale can build up on hemlock rapidly if left unchecked. Look underneath needles for scale.

Large populations can result in stunted growth, yellowing of leaves, branch and twig dieback (Cranshaw, 2004; Johnson and Lyon, 1991).

Control options are lightweight horticultural oil applications or specific soil or trunk injections of the appropriate insecticide if they are proven effective before you decide. I have used horticultural oil applications on this scale group with excellent results. It is best to contact your state university extension office for up to date controls for most hard scales.

Common name: Hemlock woolly adelgid

Order: Homoptera

Family: Adelgidae

This needle and twig sap-sucking insect was introduced into the United States during the 1950s and has traveled up the eastern seaboard into parts of New England from southern states over the past few decades.

If left untreated, the hemlock woolly adelgid can kill a 30-foot hemlock in seven to 10 years (personal observation). Adelgids have piercing-sucking mouthparts and their feeding damage to the affected needles turn dull in color and lead to yellowing then turning brown, ultimately falling off. Branch dieback occurs later.

Adelgids have incomplete or gradual metamorphosis (no pupal stage) and are very small gray colored insects. Adults have characteristic white waxy covering over their bodies. See figure 9. A female can lay over 100 eggs by late March. During the summer another generation occurs, going temporarily dormant during the heat of summer, but resume feeding and growth in the fall (Cranshaw, 2004).

Figure 9. Hemlock woolly adelgid adults are covered in their protective white wax covering. A diagnostic characteristic of infestation.

You can control this pest using the approved insecticides either as trunk injections, soil injections or soil drenches. Lightweight horticultural oil works very effectively on this pest and is the recommended control option in most cases. For more information about this pest visit the following website http://ag.umass.edu/landscape/fact-sheets/hemlock-woolly-adelgid

For more information about other adelgids visit this website http://ag.umass.edu/landscape/fact-sheets/adelgids

Common name: Boxwood pysllid

Family: Psyllidae

The psyllids are similar to aphids in their plant sap-sucking feeding behavior, but unlike aphids, they are strong jumpers and move quite quickly when disturbed. Nymphs are gray colored and produce wax-like coatings over their bodies. Like most homopteran pests they are host specific (Borror et al, 1989; Pirone, 1978).

For those landscapers that care for boxwood, the boxwood psyllid (Cacopsylla buxi) feeds on the developing buds and new leaves of American boxwood resulting in the cupping of the leaves (leaf distortion) (Johnson and Lyon, 1991; Cranshaw, 2004; Pirone, 1978). See figure 10. Adults are green colored and about ¼ inch long with clear wings (Pirone, 1978).

Figure 10. Here you can see the characteristic leaf cupping on American boxwood caused by the sap-sucking boxwood psyllid.

Common name: Lygus bugs and four lined plant bug

Order: Hemiptera

Family: Miridae (plant bugs)

The four lined plant bug (Poecilocapsus lineatus) (figure 11) has a stylet or piercing-sucking mouthpart that penetrates plant cells, mostly in leaves for sap. Plants attacked show white to dark leaf stippling which can eventually dry out and fall away from the leaf leaving a hole in the leaf (Johnson and Lyon, 1991).

Figure 11. The four lined plant bug. Notice the black stripes on its wing covers (elytra) – a diagnostic feature.

Adults are about ¼ to 1/3 of an inch long, ranging in color from yellow to green with four characteristic black stripes on its forewings (see figure 12). Immatures or nymphs go through five instars and range in color from red to yellow (Cranshaw, 2004).

Figure 12. Adult tarnished plant bug.

This small, quick moving insect (when disturbed) makes small white and/or black (dead tissue) flecks in leaves on a large variety of plant hosts both woody and herbaceous. Garden plants commonly attacked are honeysuckle, rose, azalea, forsythia, dogwood, sumac, hydrangea, many fruits and vegetable crops and flowers such as Shasta daisy, coreopsis (tickseed), dahlia, purple coneflower (Echinacea), morning glory (ipomoea), lavender (lavendula), lupine (lupines), geranium (pelargonium), zinnia, mint, and many others (Pirone, 1978; Cranshaw, 2004).

The tarnished plant bug (Lygus lineolaris) is a light brown insect about 1/3 of an inch long with a triangular yellow colored scutellum on its thorax. Like the four lined plant bug, it inserts its piercing-sucking mouthparts into leaf cells extracting sap. Nymphs are yellow to green in color, wingless and go through five instars before reaching adulthood (Gill et al, 1999; Ellis and Bradley, 1992).

The toxin in its saliva causes plant part distortions to developing leaves, flowers and fruits (Cranshaw, 2004; Gill et al, 1999). For example, the tarnished plant bug’s saliva has a toxin which causes china asters to drop their flowers when the bug feeds just below the flower buds (Pirone, 1999). The bug’s salivary toxin is the killing agent.

Other garden plants susceptible to being damaged by this pest are dahlia, gladiolus, impatiens, salvia (sage), viburnum, zinnia, vegetable crops, weeds, pines, white spruce, Douglas fir, and larch (Johnson and Lyon, 1991; Cranshaw, 2004). About 385 plant species serve as hosts for this insect (Johnson and Lyon, 1991).

To aid in controlling this pest one should keep your garden clean of weeds because this pest feeds and lives among many weed species.

Figure 14. Rhododendron lace bugs with accompanying fecal spots and damage.

Other common bug pests are rhododendron lacebug (see figure 14 illustrating leaf damage to rhododendron) and azalea lacebug (see figure 15). The following websites will have information about these pests. http://ag.umass.edu/landscape/fact-sheets/andromeda-lacebug.

Figure 15. Close up of azalea lace bug damage.

Common name: Leaf miners

Orders: Lepidoptera, Hymenoptera, Coleoptera and Diptera

Leaf mining insects are the larvae of the following insect orders: Lepidoptera (butterflies and moths), Hymenoptera (bees, ants, wasps and sawflies), Coleoptera (beetles), and Diptera (true flies).

Figure 16. Serpentine leaf mine on aspen in Maine, August 2019.

There are hundreds of leaf-mining insects comprising these four insect orders. Mines are mostly aesthetically unpleasant to the plant buying customer. Leaf miners are not a devastating pest to older plants. They may cause leaf drop to seedlings in nurseries, but otherwise they don’t pose a major control problem in the established landscape. Figure 16 shows a leaf mine on a small aspen in Steuben, Maine, August 3, 2019.

Mines are chewed by larvae between the upper and lower leaf surfaces and can be linear, spiral, blotch or branching. See figure 16. It all depends on the leaf miner species and host plant. The following video shows sawfly larvae on a birch leaf in Maine during a seminar I took this past summer. (Credits are included in time lapsed video.)

Non-Insect Pests

Common name: Spider mites

Class: Arachnida

Order: Acarina

Family: Tetranychidae

Spider mites are not insects and they do not have wings. They are related to the many other species of arachnids comprising the individual orders of spiders, scorpions, harvestmen (daddy longlegs), pseudoscorpiones, and the like (Johnson and Lyon, 1991; Borror et al, 1989).

Spider mites undergo five developmental stages: egg, six-legged larva, proto-nymph, deuto-nymph, and finally the eight legged, reproductively capable adult (Johnson and Lyon, 1991).

Their mouthparts are different in design from insects that draw sap from leaf and stem cells. Instead of piercing-sucking stylet mouthparts representative in aphids, scales and bugs, spider mites have chelicerae which are modified to puncture plant cells to release sap. Once the sap is exposed, the spider mite sucks up the sap into its oral cavity (Johnson and Lyon, 1991). This feeding action is a two-stage process.

Plant symptoms of spider mite feeding is a speckled bronzing look on affected leaves which can look like pale green or light yellow depending on the plant host species (Olkowski et al, 1991).

Commonly silk webbing is evident. Silk is produced by special glands associated with their mouthparts (Johnson and Lyon, 1991; Borror et al, 1989).

Adult spider mites are tiny, no more than 1/50 of an inch long and range in color from pale green to yellow to light red (Ellis and Bradley, 1992). Spider mites can be very damaging pests and can build up their populations rapidly. They are difficult to control with some organic methods, but applying lightweight horticultural oil weekly for three weeks in a row will reduce the population. The oil suffocates the eggs, nymphs and adults. Both nymphs and adults feed on the same plant at the same time and many generations can occur in one growing season once they start.

The miticide called Floramite is very good at killing off these and other mite pests. In the landscape, keeping weed populations down and watering/misting garden plants help in the reduction of this pest because spider mites thrive in hot, dry conditions. You must monitor for this pest once you detect it, and control it immediately.

There is a broad host range of more than 150 species of plants (Gill et al, 1999). Hosts range from woody to herbaceous plants and include more than what I’m listing but include, ageratum, antirrhinum, boxwood, convallaria, cotoneaster, delphinium, dianthus, gladiolus, hedra, hemerocallis, impatiens, pachysandra, phlox, cherry, oaks, viburnum, euonymus, dogwood, and many others (Ellis and Bradley, 1992; Cranshaw, 2004).

To know more about spider mites, check out this website, http://ag.umass.edu/landscape/fact-sheets/spider-mites-in-landscape-nursery

Common name: Slugs and snails

Phyllum: Mollusca

Class: Gastropoda

Order: Sytlomatophora

Slugs and snails are soft-bodied invertebrates that are closely related to mussels and clams, have unsegmented bodies and possess antennae. Most are night feeders. Many need shade for long periods during the daylight hours.

In wet areas and seasonally wet times during the growing season when humidity is high, these mollusks can cause severe plant damage by chewing leaves. They cause much damage when not controlled in nurseries and home garden beds. There are native and exotic species in the United States with approximately 700 species of land snails and close to 40 species of slugs (Gill et al,1999).

Figure 17. Common garden snail. Its small size and cryptic coloration helps it hide among gardeners.

Snails (figure 17) have an external shell and slugs (figure 18) do not. Both are plant feeders and avoid hot and dry conditions, which is why they tend to feed at night and in deep shade during the day. Both produce slime trails and feed on leaves causing uneven holes and have been known to consume entire leaves and seedlings close to the ground (Gill et al, 1999).

Figure 18. Common garden slug.

Controlling these invertebrates using traps bought at garden centers works well. You can also place boards or pieces of cardboard on the ground near your plants to create a dark and humid environment for them to colonize. This is a very good monitoring method (Gill et al, 1999). Once you get a population under your coverings you can hand pick them into a receptacle for trash disposal. Some people have used beer traps (filling a plate with beer) to attract these critters into the beer to get them inebriated for hand picking and disposal.

Literature Cited

Borror, D. J., C. A. Triplehorn and N. F. Johnson. 1989. (6th ed.) Introduction to the Study of

Insects. Saunders College Publishing, Harcourt Brace College Publishers, N.Y. 875p.

Cranshaw, W. 2004. Garden Insects of North America. Princeton University Press, N.J. 656p.

Ellis, B. and F. M. Bradley (editors) 1992. The Organic Gardener’s Handbook of Natural Insect and Disease Control. Rodale Press, Emmaus, Pennsylvania. 534p.

Gill, S., D. L. Clement and E. Dutky. 1999. Pests and Diseases of Herbaceous Perennials. Ball Publishing, Batavia, Illinois. 304p.

Johnson, W. T. and H. H. Lyon. 1991 (2nd ed.) Insects that Feed on Trees and Shrubs. Cornell University Press, Ithaca, N.Y. 560p.

Lanier, Jason and Mary Owen (editors). 2015. Professional Turf IPM Guide.

Published by UMass Extension Turf Program. http://ag.umass.edu/turf/professional-turf-ipm-guide

Olkowski, W., S. Daar and H. Olkowski. 1991. Common Sense Pest Control. Least toxic solutions for your home, garden, pets and community. The Taunton Press, Newtown, Ct. 715p.

Pirone, P. P. 1978. (5th ed.) Diseases and Pests of Ornamental Plants. John Wiley and Sons, N. Y. 566p.

Schumann, G. L., P.J. Vittum, M.L. Elliott and P.P. Cobb. 2002. IPM Handbook for Golf Courses. John Wiley and Sons, Inc. Hoboken, N.J. 264p.

About the Author

Bruce Wenning has been on the ELA Board of Directors since 2003. He has university degrees in plant pathology and entomology and is the horticulturist at The Country Club in Brookline, Massachusetts.

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