An environmentally friendly pest control method

"Breakfast of champions" to increase the sexual activity of insects... barren

A new method developed in the Faculty of Agriculture, Food and Environment by Robert H. Smith of the Hebrew University increases the sexual activity of sterile insects that are used for environmentally friendly pest control purposes. The method depletes the populations of harmful insects without harming the environment or human health and thereby contributes to increasing crops and the profitability of farmers.

Pest control today is mainly based on a variety of chemical substances. These substances violate the ecological balance in the habitat, penetrate the groundwater and in many cases even harm human health. In addition to this, over the years it became clear that the use of chemical pesticides provides only a temporary solution to the problem of pests developing resistance to the substances.

As a substitute for the use of chemical substances, Prof. Boaz Yuval from the Faculty of Agriculture at the Hebrew University perfected an existing method for sterilizing harmful insects or disease-carrying insects. The method can be applied to a variety of disease-carrying mosquitoes and fruit flies that cause great damage to many agricultural crops, such as citrus and olives. As part of the method, millions of insects are raised in a factory, the males are genetically isolated and sterilized before being released back into the field. The expectation is that the infertile males will mate with the wild females, they will lay unfertilized eggs and thus the pest population will decrease.

However, it turned out that the sterilization process affects the sexual ability of the insects and actually harms the effectiveness of the method. In Prof. Yuval's laboratory, they studied the physiological and behavioral aspects that affect the success of the sexual activity of the insects and found that one of the factors that affect the sexual function of the males is their diet.

Prof. Yuval found that feeding the males high protein food improves their sexual function. In a study done in collaboration with Prof. Edward Yurkevitz, and research students Adi Bachar, Miki Ben-Yosef, Sagi Gabriel and Eyal Ben-Ami from the Faculty of Agriculture, it was found that the bacteria found in the digestive system of fruit flies have a distinct effect on their sexual success.

Based on the discovery, recently published in the journal International Society for Microbial Ecology, Prof. Yuval and his research colleagues are developing a "breakfast of champions" rich in proteins and bacteria found in the flies' digestive system. The probiotic meal is given to them before they are released into the field, and improves their sexual function.

Today, the method developed in Prof. Yuval's laboratory is applied against a variety of fruit flies in Israel, the USA, Thailand, the Philippines, Australia and Mexico. At the same time, they are now trying to implement the method against mosquitoes in different parts of the world, such as in Africa and the Caribbean.

"Successful application of the method will result in its expansion to various types of insects that harm plants and animals as well as pests that transmit diseases to people while protecting the environment and health," notes Prof. Yuval.