Anti-oviposition and repellence of Cordyceps fumosorosea against Spodoptera exigua

Abstract

Anti-oviposition induced by Cordyceps fumosorosea FG340 to Spodoptera exigua and its persistence had been assessed on the Chinese cabbage seedlings sprayed with 0, 106, 107 and 108 conidia per mL in greenhouse and laboratory. In a randomized complete block, four couples (males and females) of moths were released in each cage. In the laboratory, the percentage of egg laid varied significantly between treatments with 59.8, 14.8, 11.9, and 13.5% on 0, 106, 107 and 108 conidia per mL; respectively. Similarly, in the greenhouse, the percentage of eggs laid differed significantly between suspensions with 88.18, 8.7, 0, and 3.13% on 0, 106, 107, and 108 conidia per mL; respectively. Repellence study showed that there is a major difference between suspensions with average 34.55, 35.21 and 40.02% for 106, 107 and 108 conidia per mL; respectively. Endophytic C. fumosorosea and its culture fluid affect the behavior of armyworm larvae. The concentration of 108 conidia per mL can affect the oviposition of the armyworm.