A. G. MURUGESAV AND JOHN RUBY
Abstract
Eichhornia crassipes is one of the most notorious aquatic weeds that causes serious ecological and economic problems. The water hyacinth weevils Neochaina bruchi and :Veochetina eichhorniae have proven themselves to be efficient in suppressing the weed growth. However environmental conditions influence the behaviour of biocontrol agents. Changes in the feeding behaviour of the weevils in relation to thermal variation have been compared at different constant temperatures from 203C to .1Sk- at 2\ intervals, N \ imum feedino,- occurred at 30k7 and so can be considered optimum. Feeding rate of the male and female NV(VVilS compared at the same temperature treatments reveal that females of both species fed more than aid the males,