Development of the Parasitoid Fly Drino inconspicuoides (Diptera: Tachinidae) in the Host Mythimna separata: Effect of Temperature and Clutch Size

Abstract

The development of the tachinid fly, Drino inconspicuoides, a polyphagous and gregarious ovolarviparous parasitoid of lepidopteran larvae was investigated in the laboratory, under different regimes of temperature and varying clutch sizes, using the host, Mythimna separata. The objective of this work was to determine the effect of clutch size (number of maggots per host) and varying constant temperatures on development and survival of D. inconpicuoides in order to optimize rearing for this species. Development was studied at seven temperature regimes 15, 17.5, 20, 22.5, 25, 27.5 and 30ºC at 60-70% RH and a photoperiod of 16L: 8D. Larval developmental time decreased from 18 days for males, 16 days for females at 15ºC to about 6 days for both male and female at 30ºC. Regardless of the number of maggots laid per host, not more than 8 puparia egressed and pupariated per host. Increasing clutch size resulted in decreased developmental time, reduced puparial weight and reduced emergence/survival of parasitoids. The study provides key information relevant in optimizing rearing procedures for a tachinid parasitoid.