THE EFFECT OF PARASITISM BY HYPOSOTER-DIDYMATOR [HYM, ICHNEUMONIDAE] ON FOOD-CONSUMPTION AND UTILIZATION BY SPODOPTERA-LITURA [LEP, NOCTUIDAE]

The effect of parasitism by Hyposoter didymator (Thunb.) [Hym. : Ichneumonidae] on food consumption and utilization by Spodoptera litura (Fb.) [Lep. : Noctuidae] was studied for seven days, during which the parasitoid completed its larval development. Food consumption, weight gained and faeces produced were significantly less in parasitized larvae than in unparasitized larvae after the 4th day following parasitization. Approximate digestibility was higher in parasitized larvae after the 2nd day following parasitization. Efficiency of conversion of ingested and digested food into body weight was greater in unparasitized larvae after the 2nd day of parasitization. There seems to be a definite immediate advantage to the crop on releasing the parasitoid due to the reduced consumption of food.