Effect of food deprivation on survival and development of larvae of Idaea inquinata

Food shortage on the development of larvae of Idaea inquinata (Scopoli) was considered. Experiments were carried out at 26 ± 1 °C, 70 ± 5% RH, and a photoperiod of 16:8 (L:D). Fifty larvae of first, second, third, and fourth instar fasted after the moult, were observed. Larvae from the first to the third instar were deprived of food for two, four, six, eight, and ten days; after the different periods without food, 0.1 g of artificial diet was gradually added. In another experiment, larvae were fed ad libitum for three, five, and seven days and then starved. Only fasted fourth instar larvae developed into an adult, the other instars larvae died. When food was reintroduced after a period of fast, 100% mortality was observed after 6 days fast in first instar larvae, after 8 days in second instar larvae and after 10 days in third instar larvae. When food was available after the moult for few days, larvae of first, second, and third instar can afford at most only one moult and died.