THE CHEMOSTERILIZING ACTIVITY OF SOME MYCOTOXINS AND THEIR INFLUENCE ON THE DEVELOPMENT AND SURVIVAL OF SPODOPTERA-LITTORALIS (BOISD) (LEP,NOCTUIDAE)

The effects of four mycotoxins: aflatoxin B-1 (AFB(1)), aflatoxin B-2 (AFB(2)), aflatoxin G(1) (AFG(1)) and kojic acid (KA) on Spodoptera li ttoralis were investigated. Second instar larvae were allowed to feed on an artificial diet containing various concentrations of either AFB( 1) (0.5, 1, 2, 2.5, 3 and 3.5 ppm), AFB(2)(2, 3 and 4 ppm), AFG(1) (1, 2, 3 and 4 ppm), or KA (up to 100 ppm). Mortality, development time, fecundity, egg hatchability and adult longevity were determined for ea ch treatment and compared to control values. AFB(1)(2-3.5 ppm) and AFG (1) (3 and 4 ppm) delayed the larval and pupal development and reduced the fecundity and hatchability. AFB, (4 ppm) reduced fecundity and ha tchability but did not affect the development rate. The highest mortal ity was caused by AFB(1) (3.5 ppm). KA had no remarkable effect when g iven alone, even in concentrations up to 100 ppm. Yet it potentiated t he toxicity and sterilizing activity of AFB(1). A combination of AFB(1 ) (3.5 ppm) and KA (75 ppm) caused more than 92% sterility among male and female moths. Sterilized males exhibited good, though not fully eq ual, mating competitiveness against control males. The possibility of making use of the chemosterilizing activity of these mycotoxins is dis cussed.