Factors influencing the developmental rates and reproductive potentials of Telenomus busseolae (Gahan) [Hym: Scelionidae], an egg parasitoid of Sesamia calamistis Hampson (Lep: Noctuidae)

The effect of seven constant temperatures on the development of Telenomus busseolae was determined, using Sesamia calamistis eggs as the host. The developmental threshold calculated was 13.7 degrees C, the optimum temperature was 31 degrees C, and the maximum temperature at which no parasitoid emergence occurred was 34 degrees C. Female I: busseolae began ovipositing immediately after emergence. They produced more offspring during the first 24 h of adult life than during any subsequent period. At 20 degrees C, adult females lived twice as long as those at 30 degrees C (21.7 and 11.0 days, respectively). Total progeny of T. busseolae was significantly highest at 27 degrees C. Mean fecundity ranged from 61 to 182 offspring per female. The effect of host age and host deprivation on the host parasitism rate, egg viability, and sex ratio of II busseolae was also investigated. Only parasitism and emergence rates were affected by host age. The numbers of total progeny were the same between 0 and 10 days of host deprivation, whereas longevity tended to increase from 12.8 to 23.4 days from 0 to 14 days of withholding hosts. The percentage parasitoid emergence and the sex ratio were not affected by withholding hosts, I: busseolae is adapted to an ecosystem with strong environmental fluctuations that cause temporary scarcity of hosts and food. (C) 1997 Academic Press