Agistemus exsertus (Acari: Stigmaeidae) predation on insects: life history and feeding habits on three different insect eggs (Lepidoptera: Noctuidae and Gelechiidae)
2006 - Volume: 46 Issue: 3-4 pages: 203-209
Life history and reproductive parameters of the predatory mite Agistemus exsertus were studied, to evaluate its potential as a predator of Agrotis ipsilon, Spodoptera littoralis and Phthorimaea operculella eggs as an alternative food substance in the laboratory. Total developmental time of the immature stages was the shortest on eggs of S. littoralis and A. ipsilon, followed by P. operculella. Fecundity was highest on S. littoralis eggs (68.9 eggs; 3.4 eggs/female/day), then A. ipsilon eggs (49.9 eggs; 2.5 eggs/female/day) and lowest on P. operculella eggs (4.9 eggs; 0.6 egg/female/day). Intrinsic rate of increase (rm), net reproductive rate (Ro) and finite rate of increase (lambda) followed the same pattern, S. littoralis (0.21, 44.07 and 1.23, respectively), A. ipsilon (0.18, 30.37 and 1.20, respectively) and P operculella (0.03, 2.29 and 1.04). Mean generation time (days) was the shortest on S. littoralis eggs (17.89), followed by A. ipsilon eggs (18.91) and then P. operculella eggs (20.78). The sex ratio of the progeny was strongly female biased (female: male = 1.8: 1 and 1.5: 1) when both noctuid eggs were provided.
Please read and follow the instructions
to post any comment or correction.