Time to death from starvation and compulsive killing by the larvae of Toxorhynchites splendens (Diptera: Culicidae).

Time to death from starvation and compulsive killing without eating of the prey by larvae of Toxorhynchites splendens were studied in the laboratory. The first and second instars survived without food for 3 days while third and fourth instars survived for 7.8 and 14 days, respectively. When the corresponding instars of Aedes aegypti, Anopheles stephensi or Culex quinquefasciatus were offered, the number of prey killed but not eaten ranged from 0 to 15 per 40 prey larvae. Compulsive killing of Ae. aegypti was mainly at its third instar by 9- and 10-day old T. splendens. Compulsive killing of An. stephensi was mainly at its second and third instars by young and older ages of T. splendens but older T. splendens also killed fourth instar of An. stephensi. Compulsive killing of Cx. quinquefasciatus was of all its instars and mainly by young T. splendens. There was a significant negative correlation between the amount of food eaten per predator and the number of prey killed compulsively. The number of larvae killed and eaten were much larger than number killed compulsively, except in the case of third instar Ae. aegypti and 9-10-day old T. splendens.