ALABAMA A&M AND AUBURN UNIVERSITIES Biology and Control of the Green June Beetle ANR-991 amage caused by green June insects, commonly called grub- Dbeetle grubs, Cotinis nitida L., worms, are also familiar sights has been increasing in Alabama (Figure 2). These large grubs are pastures, hayfields, landscapes, often found under hay bales left in home lawns, and other established the field, near manure piles, and in grassy areas. Although green June thick organic turf. beetle grubs prefer to feed on de- caying organic matter, occasionally they chew the tender roots of grass plants. Damage to turf and pasture is primarily mechanical because grub tunneling and movement in the soil uproot grass plants, which Figure 2. Fully-grown green June then dry out and die. beetle grubs Green June beetle adults are Green June beetle grubs are velvet green with orange or rust most abundant in sandy or sandy stripes along the outer margins of loam soil rich in organic matter. the wing covers (Figure 1). Beetles Green June beetle adults are attract- 1 may be ⁄2 to nearly 1 inch long. ed to the decaying organic matter Peak beetle flights begin during late that makes up a large part of the June, thus the common southeast- Figure 1. Green June beetle adult grub’s diet. Broiler litter, cow ma- ern name, June bug. The immature nure, milorganite (composted JAN FEB MAR APR MAY JUNE JULY AUG SEPT OCT NOV DEC ARCHIVE Figure 3. Life cycle of the green June beetle Visit our Web site at: www.aces.edu sewage sludge), rotting hay, and males to them. After mating, the fe- Grubs are capable of pruning stable manure all encourage green male green June beetle flies close to the roots of plants, particularly June beetle infestation. the turf or grass surface, selects a when the grubs occur in high num- Green June beetle grubs are dif- site (preferably moist, organic soil), bers. Grazing cattle easily pull the ferent from most grub species in the and digs several inches into the soil. plants growing in the loosened soil southeastern United States in that The female beetle constructs a out of the ground. Weeds quickly they come out of the ground at walnut-sized ball of soil in which colonize the bare patches created night and move from one place to she lays 10 to 30 eggs. Eggs are where a plant dies or is pulled out. 1 another. Green June beetle grubs nearly round, about ⁄16 inch in diam- Birds, armadillos, and skunks dig crawl on their backs with their legs eter. Each female may lay as many grubs out of turf and pastures, often in the air. This movement easily dis- as 75 eggs during a 2-week period. causing even greater damage in the tinguishes them from most other Eggs hatch in about 2 weeks. Newly process. grubs in the soil. When disturbed hatched grubs are about 3/8 inch A large, dark-colored wasp, the grubs curl up into a C-shape, long. Young grubs begin to tunnel Scolia dubia, is often seen flying typical of the grubs in their family, through the soil in search of food low over grassy areas infested with the Scarab beetles. Grubs of some (organic matter). They typically green June beetle grubs. The insect, related beetles, called Euphoria, or come to the surface to feed. sometimes called the bluewinged bumble flower beetles, also crawl In turf, the grubs usually leave wasp, attacks green June beetle on their backs. They might occa- small mounds of soil around the grubs, and is, therefore, beneficial. sionally be confused with green mouth of each tunnel. By August, This wasp is blue-black in color, June beetle grubs; however, bumble grubs are large enough for mounds slightly longer than an inch. The flower beetles are not known to to be seen on short mowed turf and rear half of the abdomen is brown cause extensive damage to turfgrass by mid-September on taller grass. In and fuzzy, with two large yellow or pastures. pastures, grubs leave trails of pul- spots. The female wasp goes down Green June beetles have one verized soil as they tunnel near the into the soil to find green June bee- generation each year (Figure 3). The surface. tle grubs. When she finds one, she grubs overwinter in the soil. They A small amount of green June stings it, causing it to be paralyzed, may become active during warm beetle tunneling can help aerate the then lays her eggs. The wasp larvae winter days. Fresh mounds of trails soil and be beneficial; however, ex- hatch and consume the green June of pulverized soil indicate fresh tensive tunneling can be harmful. beetle grub. In Alabama, wasp grub activity. Grub activity increases Tunneling loosens the soil and cre- adults are most prevalent in August as the spring weather becomes con- ates a spongy layer about 2 inches and September. Under some cir- sistently warmer. deep in heavy infestations (Figure cumstances, this insect, and some Grubs pupate in cells in the soil 4). Tunneling disrupts the contact microbial pathogens, will control a during late April and May and remain between the plant roots and the green June beetle infestation. in the pupal stage for 2 or 3 weeks. soil. This interferes with water up- Newly emerged adults remain in the take causing the plants to die. soil for an additional week or two. In most years, green June beetles leave the soil beginning in late May and continue through early August. Peak flights usually occur from June through July. As adults, green June beetles feed on fruits such as apples, peaches, and figs. Usually, they prefer to eat over- ripe or decaying fruit. Occasionally, adult green June beetles ARCHIVEfeed exces- sively and cause economic damage to grapes and small fruits. Female beetles fly over the grass surface early in the morning and settle into the grass just after daybreak. Male beetles fly during mid to late morning. Female beetles Figure 4. Pulverized soil is a typical sign of green June beetles in pastures. Notice produce substances that attract the the broad-leaved weeds that have invaded the infested area. 2 Management tion ANR-177, “Controlling White If soil is dry, irrigate before Grubs on Lawns and Turf,” will treatment. on Turf control green June beetle grubs. Make applications late in the On turf, green June beetle con- Usually, smaller amounts are re- day because grubs move to the sur- trol is site specific. In some cases, quired. In addition, low rates of car- face during the evening. the grubs do such a good job of baryl such as Sevin and acephate Treat all infested areas. aerification that control is consid- such as Orthene Turf, Tree & Otherwise, grubs may later move ered to be undesirable. This is espe- Ornamental Spray (Orthene TT&O) back into treated areas. effectively control green June beetle cially true on rapidly growing, well- 5. Keep a history of the site. grubs but not other grub species. established bermudagrass that is not Mark a landscape map with previ- closely mowed. However, green ously infested areas. This can help Homeowner Use On Lawns June beetle mounds are usually not in locating new infestations. tolerated on highly visible areas Insecticide Rate 6. Remove dead grubs if nec- such as the slopes of golf greens. carbaryl essary. Following an insecticide ap- Sod producers need to guard SEVIN 50W 3 oz/1000 sq. ft. plication, grubs emerge from the against this pest because the tunnel- Other brands of See label for ground the next evening and die on ing weakens the structural strength carbaryl may be rate information the turf or soil surface. Decaying of the sod. available. grubs not only smell bad, but also The following are steps for suc- acephate may result in slick playing surfaces ORTHENE TT&O 1.1 oz/1000 sq.ft. cessful control on turf: on athletic turf. Usually, you can 1. Be sure you have green in at least 3 gal. of water remove dead grubs from athletic June beetles. Green June beetles fields or other frequently trafficked are not the only animals that make areas with a turf sweeper such as Commercial Turf Use mounds on turf. Mole crickets make the ones used on golf courses. mounds during the spring and fall Insecticide Rate on infested turf, primarily in the carbaryl Management in southern half of Alabama. Earth- SEVIN SL 2 qt/A. worms also make mounds, the par- SEVIN 80WSP 2.5 lb/A. Pastures and ticles of which are distinct pellets. acephate Hayfields To determine which animal is creat- ORTHENE TT&O 3.4 lb/A. Green June beetles are most like- ing mounds in an area, use a mix- ly to cause damage in fields where ture of 1 or 2 tablespoons of lemon- Do not water after treatment. broiler litter or other organic matter scented dish detergent in 1 gallon of City water used for Orthene TT&O has been applied. Green June beetles water. Pour the solution over 1 or 2 sprays may be too alkaline and cause a general loss of productivity square feet of the infested area. must be buffered before Orthene and allow less desirable grasses such Wait a few minutes, and observe TT&O is added in order to obtain as crabgrass and common bermuda- what comes out of the ground. maximum effectiveness. Use a pH meter or a swimming pool testing grass to invade. In heavy infestations, You can also verify the pres- kit to determine acidity/alkalinity.