USDA researchers are looking to sabotage the love life of gypsy moths by "seeding" the tree canopy where they mate with tiny pheromone dispensers. Scientists want to disrupt mating to prevent caterpillar offspring, which are responsible for defoliating trees. The air-dropped dispensers are little more than soft plastic beads or flakes less than three millimeters in size. They are sprayed by plane as an insecticide-free defense against isolated or low-level gypsy moth infestations. Held to tree leaves by a glue-like substance--or sticker--they saturate the surrounding air with a synthetic version of the female moth's chemical sex attractant or pheromone. This thwarts the males' ability to home-in on the real chemical beacon from females. In the researchers' studies, the pheromone applications prevented nearly 100 percent of the moths from mating. As a result, the number of fertile egg masses on pheromone-protected trees was cut by 75 to 100 percent compared to trees in untreated plots. Scientists are studying various ways to distribute the dispensers for maximum effectiveness and ease of application from spray aircraft.
Insect Biocontrol Laboratory, Beltsville, MD
Kevin Thorpe, (301) 504-5689

Two of six new species of insects are candidates for biological control of paperbark, a large tree that has become the most troublesome terrestrial weed in the United States. Introduced into Florida in 1906 from Australia as an ornamental, paperbark (Melaleuca quinquenervia) now invades over 500,000 acres and causes extensive environmental and economic damage. Conventional control measures, like cutting, burning and herbicides, are costly, ineffective and environmentally inappropriate in managing this pest. ARS scientists have for the first time identified several gall midges (Lasioptera and Lophodiplosis) that are native to Australia that may suppress the growth of this tree. Several have been identified as being potential biocontrols because they are highly specific in attacking paperbark buds and leaves and in keeping it under control. Six of these insects are species new to science and are named and described in detail. Researchers trying to find natural control for this tree pest will now be able to readily identify and distinguish among these exotic insect species. Biocontrol specialists can now begin research to introduce them into Florida.
Systematic Entomology Laboratory, National Museum of Natural History, Washington, D.C.
Raymond J. Gagne/ Joseph K. Balciunas, (202) 382-1796/(510)559-5841

They're not quite insects and not quite worms--they're velvetworms, a true scientific oddity in an ongoing exhibit at the Smithsonian's Insect Zoo in Washington, D.C. Referred to by scientists as Onycophora, velvetworms look much like slugs with legs. Their cylindrical bodies are covered with growths called tubercles that give them a velvety appearance. Velvetworms can grow up to 6 inches long, with as many as 43 pairs of legs, depending on the species and sex. The creature's head sports antennae and two cone-shaped structures that squirt an adhesive material to help snare prey. Discovered in 1825, velvetworms live under logs, stones or leaves in tropical rain forests. ARS scientists collected five males and one pregnant female in Costa Rica. The female has given birth to several young that are being carefully tended at the Insect Zoo in the Smithsonian's Natural History Museum. The velvetworm exhibit is aimed at educating the public about insects and their relatives, as well as providing more knowledge about their behavior.
Systematic Entomology Laboratory, National Musuem of Natural History, Washington, DC
Dave Adamski,(202) 382-1778

A little worm with a big name--Psammomermis nitiduesis n.sp.--could be bad news for crop-damaging sap beetles. Scientists discovered the new nematode species among beetles found near sweet corn fields in two Illinois counties. Up to 80 percent of sap beetles collected in the spring were killed by P. nitiduesis. The nematode uses the sap beetles to reproduce. Sap beetles burrow into sweetcorn ears at the critical milk stage, rendering them unacceptable to consumers. The beetles also spread Fusarium and Aspergillus, fungi that produce toxins harmful to humans and animals. Effective biological controls against the beetles have been difficult to establish. Scientists are studying ways to distribute P. nitiduesis and pit it against the sap beetle throughout the Corn Belt.
Mycotoxin Research, Peoria, IL
Patrick Dowd, (309) 681-6242

Last Updated: January 28, 1997
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