Jerusalem, March 17, 2010 – An improved method for
sustainable pest control using "super-sexed" but sterile male
insects to copulate with female ones is being developed by
agricultural researchers at the Hebrew University of Jerusalem. The
scientists thus hope to offer yet another efficient and promising
avenue for supplying produce to the market by eliminating pests
without damage to the environment.
An assortment of chemicals, such as DDT, have been employed
since early in the last century to control crop pests or carriers
of diseases. However, this approach has led to the evolution of
resistance to pesticides and has severely negative impact on human
health and the environment.
As an alternative to the use of chemicals, Prof. Boaz Yuval at
the Hebrew University of Jerusalem's Robert H. Smith Faculty of
Agriculture, Food and Environment, is working on upgrading a
veteran approach, known as the sterile insect technique. This
method is currently employed against several dozen insect species.
The principle is to rear millions of individuals of the species one
seeks to control, separate the sexes, sterilize the males and
release them into the field. It is expected that the sterile males
will copulate with wild females, who will then be unable to lay
fertile eggs, thus reducing the pest populations.
However, says Prof. Yuval, the process of rearing millions of
male insects, sterilizing them and transporting them to the release
site can severely affect their sexual competitiveness. The research
in Yuval's laboratory at the Department of Entomology focuses on
improving this technique, as applied to fruit flies and
mosquitoes.
Prof. Yuval has studied the behavioral and physiological
elements that define the factors that contribute to male sexiness,
and subsequently has devised ways to confer these characteristics
on sterile males.
One of these factors is nutritional status. Yuval found that
feeding males on high protein diets significantly improves their
sexual performance. Recently (in collaboration with Hebrew
University colleague Prof. Edouard Jurkevitch and graduate students
Adi Behar, Miki Ben-Yosef, Sagi Gavriel and Eyal Ben Ami) Yuval
also found that the bacteria residing in fruit flies are important,
and that the factory reared flies lacked the bacteria found in wild
insects.
With this information in hand, Yuval and his colleagues are
formulating a high-protein, bacteria enhanced "breakfast of
champions" which will be provided to males before their release,
and significantly improve their sexual performance when released in
the field. Their work is described in the ISME
(International Society for Microbial Ecology)
Journal.
Yuval believes that successful application of this approach can
be applied to a variety of plant and animal pests, as well as to
organisms that transmit human disease, thus making an important,
organic and environmentally friendly approach to pest control.
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