Olfactory reactions of Cryptolaemus montrouzieri Mulsant (Col., Coccinellidae) and Chrysoperla carnea (Stephens) (Neur., Chrysopidae) in relation to period of starvation.
In a laboratory study, the extent of olfactory responses of the predators Cryptolaemus montrouzieri and Chrysoperla carnea at varying levels of starvation, to their prey, Planococcus citri and Acyrthosiphon pisum, resp., was measured. Results indicated that both predators, irrespective of their developmental stage, reacted more positively to their prey's odour when they were deprived of food for a certain period of time compared with when they were tested without subjecting them to starvation. The 1st-, 2nd-, 3rd- and 4th-instar larvae and adults of C. montrouzieri showed maximum response at 4, 8, 12 and 24 h of starvation, resp. Similarly, the best response of larvae of C. carnea was observed after 4, 8 and 12 h of starvation in 1st-, 2nd- and 3rd-instar larvae, resp. However, it was also evident that continued starvation for more than a certain period affected the predator's olfactory orientation negatively. The adults of C. montrouzieri differed slightly in their behaviour as they still responded positively after longer periods of starvation..