Functional Response of Two Chrysopid Predators Feeding on Helicoverpa Armigera (Lep: Noctuidae) and Aphis Gossypii (Hom; Aphididae)
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Springer
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http://link.springer.com/article/10.1007/BF02764242
Predation onHelicoverpa armigera (Hubner) eggs andAphis gossypii (Glover) nymphs by 3rd instar larvae ofMallada desjardinsi (Navas) andChrysoperla congrua (Walker) was studied under laboratory conditions. Single predators that had been starved for 24 hours were isolated for 1 hour in 9 cm Petri dishes containing prey at densities of 5, 10, 15, 20 and 25 per dish. A type II functional response model gave a satisfactory fit to the data in case ofM. desiardinsi preying onH. armigera. However, with C.congrua, a type III model gave a slightly better fit. ForA. gossypii, functional responses of both predators did not differ from type II, withM. desjardinsi showing a significantly lower search rate and shorter handling time thanC. congrua. Implications of these findings are discussed
Predation onHelicoverpa armigera (Hubner) eggs andAphis gossypii (Glover) nymphs by 3rd instar larvae ofMallada desjardinsi (Navas) andChrysoperla congrua (Walker) was studied under laboratory conditions. Single predators that had been starved for 24 hours were isolated for 1 hour in 9 cm Petri dishes containing prey at densities of 5, 10, 15, 20 and 25 per dish. A type II functional response model gave a satisfactory fit to the data in case ofM. desiardinsi preying onH. armigera. However, with C.congrua, a type III model gave a slightly better fit. ForA. gossypii, functional responses of both predators did not differ from type II, withM. desjardinsi showing a significantly lower search rate and shorter handling time thanC. congrua. Implications of these findings are discussed
Keywords
Mallada desjardinsi, Chrysoperla congrua, Cotton, Eastern Tanzania, Fonctional response