Parasitisation of Tetrastichus brontispae (Hymenoptera: Eulophidae), a biological control agent of the coconut hispine beetle Brontispa longissima (Coleoptera: Chrysomelidae)

The gregarious endoparasitoids Tetrastichus brontispae Ferrière is one of the important natural enemies of the coconut hispine beetle Brontispa longissima (Gestro), a serious invasive pest on coconut palm plants (Cocos nucifera L.) in Southeast Asia. Development at different temperatures, effect of host and female ages, effect of food and oviposition frequency and superparasitism were investigated in the laboratory. Females were allowed only one attack against one host in all experiments. The wasp developed in a host between 19 and 30°C, whilst no wasp completed its immature development at 16 and 31°C. Host and female ages affected parasitisation. Parasitoid emergence was high on day 0 and day 1 pupal hosts, and younger females produced more offspring than older females. The longevity of the female was affected not only by food supply, but also by oviposition frequency. The female survived longer when oviposition frequency was low. However, the total number of hosts parasitised by the female during her lifetime did not differ at different oviposition frequencies. In superparasitism, although the percentage of adult emergence and body size of offspring decreased with an increasing number of attacks per host, a host parasitised by up to four females could produce parasitoid offspring.