Intraguild Predation and Cannibalism between Two Phytoseiid Mites, Neoseiulus californicus and Amblyseius andersoni

Intraguild predation and cannibalism (conspecific predation) of two generalist phytoseiid mites were determined in this study. Adult females and protonymphs of Neoseiulus californicus (McGregor) and Amblyseius andersoni Chant were considered as intraguild and cannibalistic predators, provided with eggs, eggs+larvae and protonymphs as intraguild or conspecific prey. A side from predator species and prey type (IG prey versus conspecific prey), females exhibited lowest predation rates on eggs. Not including prey type, the highest predation rate was recorded in A. andersoni and N. californicus when provided with eggs+ larvae. Female predators were not interested in the first nymphal stage of prey and there was no significant difference in consumption rates and oviposition when provided with conspecific or intraguild prey. Feeding on intraguild larval prey did not only increase mortality of A. andersoni immatures, but also decreased their consumption rates. For N. californicus immatures, predation on IG larval prey was higher than on conspecific larvae. Therefore, it seems that the predator species are able to survive on both con- and heterospecific prey.