Laboratory effects of ingestion of azadirachtin by two pests (Ceratitis capitata and Spodoptera exigua) and three natural enemies (Chrysoperla carnea, Opius concolor and Podisus maculiventris)

The effects of azadirachtin on two pests: neonate larvae and newly emerged adults of Ceratitis capitate (Wiedemann) and last instar larvae of Spodopte ra exigua (Hubner); and three natural enemies: newly emerged adults of Opiu s concolor Szepligeti, second instar larvae of Chrysoperla carnea (Stephens ), and fifth instar nymphs of Podisus maculiventris (Say) were studied in l aboratory.,Adult insects were exposed to a non-oil formulation of azadirach tin (Align(R), emulsifiable concentrate 3.2% azadirachtin, Sipcam Inagra, S pain) via their drinking water and immature instars were reared in the pres ence of the insecticide-treated diet. The natural enemies were exposed to a t least the maximum field recommended concentration of the insecticide (0.1 5% v/v). Azadirachtin wets highly toxic to neonate larvae of C. capitata an d prevented adult emergence at a concentration of I mg a.i l(-1). When adul ts were fed the insecticide at the maximum recommended concentration their survival Mns not affected bur egg laying was totally inhibited Last instar S. exigua larvae were also very susceptible (LC50 = 7.7 mg a.i. l(-1)) and at a concentration of 10 mg a.i. l(-1) fecundity of surviving adults, and e gg fertility, were reduced by 72 and 85%, respectively. Effects on O. conco lor were large, and significant reductions in longevity, percentage of atta cked hosts, and progeny size per female, were recorded The predator P. macu liventris was much less sensitive to azadirachtin, but slight reductions in survival of emerged adults and of reproductive parameters occurred. The in secticide had no significant effect on C. carnea Inn ae fed with treated Si totroga cerealella (Oliver) eggs, probably because of its inability to pene trate inside the egg.