Releasing sterilized insects into the environment is one way of pest control known thus far. Now this method could be come more effective when we make the insects super-sexed but turn them sterile, say Israeli scientists.
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.
In the sterile insect technique, on the other hand, millions of species targeted are reared, sexes separated, males sterilized and then released into the field. But in the process their sexual competitiveness is also severely affected - which means the copulation itself might not come about, thus sabotaging the entire effort, says, Prof. Boaz Yuval at the Hebrew University of Jerusalem's Robert H. Smith Faculty of Agriculture, Food and Environment.
Now research in Yuval's laboratory at the Department of Entomology focuses on improving the sterile 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
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.