Natural predators could be key to pest control

Date:10-29-2012

Natural insect predators could become a key method of controlling aphids in arable crops, some of which carry diseases such as barley yellow dwarf virus.

Research being carried out at the University of Hull aims to help farmers accurately and quickly assess levels of parasitism by insect predators, which control crop destroying pests such as aphids, says Darren Evans, lecturer in conservation biology at the University of Hull's department of biological sciences. "This is currently a slow and unreliable process."

Aphids are one of the most prolific pests affecting crop production, substantially reducing yields and making them more vulnerable to disease. An adult parasitoid wasp kills an aphid by injecting an egg inside it and the resulting larvae then consumes the entire body contents.

Within a few days, the aphid dies and mummifies as the larva grows larger inside it. After around two weeks, the pupa becomes an adult and eats a hole in the mummified aphid's body to escape, explains Dr Evans.
 
The researchers will in future be able to rapidly determine the type and rate of parasitism by examining a sample of pests from a crop. "This valuable information will enable the farmer to decide whether or not intervention is needed, thus helping to prevent the overuse of pesticides."

The team hopes that its research will eventually lead to parasites being routinely used for as pest control on open farmland.

Dr Evans adds: "Developing this system will let us detect insect parasitism rates so that we can better manage and enhance the environment. Using this approach, we will be able to predict pest outbreaks, reduce pesticide use and have an improved understanding of how to better manage the countryside for natural pest control."