Biological Control of Plant Pests
- Hemlock Woolly Adelgid
- Mexican Bean Beetles
- Mosquitoes
- Scale
- Tarnished Plant Bugs
- Canada Thistle
- Mile-a-Minute Weed
- Purple Loosestrife
- Insects currently raised in Phillip Alampi Beneficial Insect Rearing Laboratory
- Hemlock Woolly Adelgid
The Hemlock Woolly Adelgid is a small sap-sucking insect, originally from Asia, which is killing hemlock trees throughout the state. The Department is raising and releasing Laricobius nigrinus, the Derodontidae beetle, that feeds on hemlock woolly adelgid. Some hemlock stands are slowly rebounding, indicating the beetles released in the past might be impacting the adelgid problem.
The Effects of Hemlock Woolly Adelgid in Natural Hemlock Stands in New Jersey Annual Report 2006
- Mexican Bean Beetles
Mexican Bean Beetles feed on the foliage of soybeans, snap beans and lima beans, reducing the crop yield. Since 1980, with support from the New Jersey Soybean Board, the laboratory has been releasing a parasitic wasp, Pediobius foveolatus, in New Jersey soybean fields to control this pest. The wasp, which cannot survive NJ winters, attacks the larvae of the Mexican bean beetle, and must be reared in the laboratory and released into soybean fields each summer.
Mexican Bean Beetle. Photo by: Whitney Cranshaw, Colorado State University, www.insectimages.org
It has been very effective at controlling bean beetles; virtually no insecticides have been applied to the state’s soybean crop in recent years and pesticide
applications for bean beetle control have been reduced on snap beans and lima beans, saving growers hundreds of thousands of dollars annually and reducing insecticide applications by thousands of pounds.
Biological Control of the Mexican Bean Beetle using the Parasitic Wasp Report 2006
Pediobius attacking Mexican Bean Beetle larvae
- Mosquitoes
Mosquitoes spread West Nile Virus and Eastern equine encephalitis; these diseases can affect both man and animals. The Department is working with the State Mosquito Control Commission on a pilot project to mass-produce a small aquatic crustacean that is a voracious feeder on mosquito larvae. These nearly microscopic aquatic crustaceans, known as copepods, naturally occur in New Jersey, and may be useful to control mosquitoes breeding in standing water and tire piles.
- Scale
Scale insects suck the sap from stems and leaves. Euonymus scale and alatus scale feed on
ornamental euonymus bushes, causing them to drop their leaves. This is a particularly serious problem in landscapes. Cybocephalus sp. nr. nipponicus, a tiny scale-eating beetle from China, has successfully been laboratory reared and released in the landscape on plants infested with Euonymus scale and Euonymus alatus scale.
Cybocephalus nipponicus
Cybocephalus will feed on a number of species of hard shell scales, including the Elongate Hemlock Scale, commonly found in hemlock trees feeding on needles and causing a decline in the trees. Beetles were observed feeding on Elongate Hemlock Scale in Mercer and Monmouth Counties through natural dispersal from Euonymus Scale release sites. The Department of Agriculture has established a number of release sites in hemlock stands in Passaic, Hunterdon, Sussex, Warren, and Gloucester Counties; and is cooperating with Rutgers University researchers, and biologists with the PA Dept. of Conservation and Natural Resources, Bureau of Forestry to study its effects on Elongate Hemlock Scale.
Mass Release and Recovery of Cybocephalus nipponicus on Elongate Hemlock Scale Annual Report 2006
- Tarnished Plant Bugs
Tarnished Plant Bugs feed on many plants, including forage crops, small grains, stone fruit, strawberries, and vegetables. Their feeding can damage fruit and reduce crop yields. A small wasp from northern Europe that feeds on the plant bug nymphs was established by USDA in the mid-1980s, and continues to spread northward from Mercer County to Canada. The Department is developing a mass rearing technique for a related wasp species from the Mediterranean region, Peristenus relictus.
Tarnished Plant Bug Annual Report 2006
Peristenus stygicus attacking Tarnished Plant Bug nymph
- Canada Thistle
A European gallfly whose larvae feed only on Canada Thistle has been established in Gloucester, Morris, Mercer, Monmouth, Salem, Somerset, Sussex and Warren Counties. Galls containing the larval stage of the fly are collected from Canada thistle plants located in field insectaries, and placed in a field cages until spring when they are redistributed to other thistle-infested sites. The gallfly has been redistributed to infested sites throughout the state, and is spreading naturally. The Department is studying the effect of the gallfly in reducing the flowering and spread of Canada thistle.
- Mile-a-Minute Weed
Mile-a-Minute Weed, Polygonum perfoliatum, can grow up to six inches per day, with mature plants reaching six feet. It can climb over, and shade out native plants at the edges of woods, along stream banks, and roadsides. Mile-a-minute can also be a problem in untilled agricultural areas such as Christmas tree farms and reforestation seedling plantations. Mile-a-minute is native to India and Eastern Asia, and was accidentally introduced into Pennsylvania in the late 1930’s. The Department is cooperating with the US Forest Service and the University of Delaware in developing a colony of tiny weevils, Rhinoncomimus latipes, imported from China, that feed specifically on Mile-a-minute weed, and to establish this beetle in the US.
- Purple Loosestrife
Purple Loosestrife is an exotic and invasive noxious weed that is threatening New Jersey's wetlands. It damages the state’s wetlands by displacing native plants essential to wildlife for food and cover. The Department is rearing and releasing two species of leaf eating beetles, Galerucella spp., that feed on purple loosestrife to control this weed pest in wetland areas. Since 1997, more than 1,500,000 Galerucella spp. beetles have been released at 100 sites, in 16 of the 21 counties throughout NJ.
Numerous sites are continuing to show high levels of beetle activity and feeding damage; the loosestrife population is being reduced and native wetland plants are beginning to populate
these previously infested sites. The Galerucella spp. beetles have been recovered up to twelve miles from a release site.
Purple Loosestrife Annual Report 2006
Galerucella -- Photo by J. Zhang
- Insects currently raised in Phillip Alampi Beneficial Insect Rearing Laboratory
- Colorado potato beetle (CPB), Leptinotarsa decemlineata
- Mexican bean beetle (MBB), Epilachna varievestis
- Mexican bean beetle larval parasite, Pediobius foveolatus
- Predators of purple loosestrife (Lythrum salicaria): Galerucella pusilla and Galerucella calmariensis
- San Jose scale, Quadraspidiotus perniciosus
- Euonymus scale predator, Cybocephalus nipponicus
- Hemlock woolly adelgid predators, Laricobius nigrinus (Derodontidae beetle)
- Tarnished plant bug (TPB), Lygus lineolaris
- Tarnished plant bug parasitoid, Peristenus relictus
- Mile-a-Minute predator, Rhinoncomimus latipe
Certain insects are available for purchase. A USDA permit is required for all interstate shipments. For more information contact: Tom Dorsey at (609) 530-4192
