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NC State entomologists win pest control grants

September 11, 2008

Media Contacts: Dr. Jules Silverman, professor of entomology, North Carolina State University, 919.513.2468 or; Steve Bambara, North Carolina Cooperative Extension Specialist, North Carolina State University, 919-515-1661 or; Dr. Wes Watson, professor of entomology, North Carolina State University, 919.513.2028 or

North Carolina State University scientists will use two U.S. Department of Agriculture Southern Region IPM Center grants to test methods of controlling ants and flies.

Dr. Jules Silverman, professor of entomology, and Steve Bambara, North Carolina Cooperative Extension specialist, will use a $94,432 grant to test a new approach to Argentine ant control. If successful, it will control both the ants and the insects that provide them with food.

At the same time, Dr. Wes Watson, professor of entomology, will use a $97,897 grant to lure flies out of swine barns and into a deadly trap.

Silverman and Bambara plan to test pest management strategies that target ants' ability to eat their favorite food: "honeydew" produced by aphids and scale insects. The researchers hope that reducing the ants’ regular food supply will drive them to another location or to toxic ant baits on the ground.

The invasive Argentine ant has become a menace in every area it inhabits. Ant colonies can span for miles, and trails of them crawling up and down trees and buildings often intimidate people. Large groups of ants can venture indoors if food is scarce outside. They also nurture and protect the aphids and scale insects that provide their food. Scientists refer to this group of insects as Sternorrhyncha. These insects feed on ornamental plants and several types of crops.

Traditional pest control treatments - sprays and baits - do not typically reduce ant numbers. Argentine ants move so quickly they can move to an untreated location before a spot spray treatment has time to settle on the ground. Baits are also typically ineffective because the ants prefer the aphid honeydew over a gel or liquid bait.

Silverman and Bambara will test pest management treatments intended to limit the ants' access to honeydew. The treatments include dormant oils, the systemic insecticide Imidacloprid, an adhesive barrier and ant baits. Dormant oils and Imidacloprid kill aphids and scale insects. Adhesive bands around tree trunks prevent ground-dwelling ants from reaching the honeydew at the tops of trees. The tests will be conducted in two locations: an office complex in Research Triangle Park, N.C., and a neighborhood in Ocracoke, N.C.

Based on study results, Silverman and Bambara will demonstrate the most successful approach to commercial landscapers, pest control operators and Cooperative Extension personnel who work with the public.

Watson will use natural repellants to make swine barns inhospitable to house and stable flies. The animal odors from a nearby barn containing an insect-killing fungus will lure the flies to their deaths. This combination of tactics is called a "push-pull" strategy.

House and stable flies are pests of swine and cattle. Both fly species feed on decaying organic matter, but stable flies also feed on animal blood. Both species spread disease to livestock and people by carrying pathogens from one location to another.

Based on previous research with cattle, Watson will use a natural repellent combination of geraniol, found in lemongrass, and undecanone, found in tomatoes. While safe to use around animals, the two substances repel flies. In previous experiments, they have proven even more effective than DEET as a repellent.

However, in low doses the repellents wear off over time. Applying repellent on a daily basis is both labor-intensive and expensive. Watson will test various dosages of the two repellents to find the lowest dose that will still repel flies after several days.

To prevent the flies from traveling to a neighboring barn, Watson will provide an appealing alternative near the repellent barn. This "trap" barn will contain animal waste products covered with Beauveria bassiana, a fungus that is harmless to livestock but deadly to insects. After coming into contact with low doses of B. bassiana, most flies die within seven days.

Watson will conduct laboratory tests first to verify the effectiveness of each strategy. If results prove satisfactory, he will apply the repellents to five hoop barns, each housing 20-50 pigs. A hoop barn is an open "greenhouse" style barn that has enough space for the pigs to sleep in a different area from where they produce their waste. Pigs usually live in the barns for 48-52 days before being taken to market.

The barn research will be conducted at the Center for Environmental Farming Systems (CEFS) in Goldsboro. CEFS promotes alternative animal and crop production systems with a holistic approach.

The Southern Region IPM Center is supported by a grant from the USDA Cooperative State Research, Education and Extension Service (CSREES) and supports the 13 southern states, Puerto Rico and the Virgin Islands. For more information about the USDA Southern Regional IPM grants or the Southern Region IPM Center, visit

Written by:
Rosemary Hallberg, communication specialist, Southern Region IPM Center, 919.513.8182 or

Posted by Dave at September 11, 2008 09:09 AM