A conservative oviposition preference in spider mites for complex habitats as a preventive strategy for reducing predation risk

Abstract

Selecting a suitable oviposition site is challenging for females due to the unpredictable nature of conditions for their future offspring. To increase survival in the face of uncertainty, egg-laying females may evolve a conservative preference strategy that simplifies decision complexity, even if such a strategy involves immediate costs. We used spider leaf mites, pubescent apple and glabrous pear leaves and two predatory species as a model system to test this hypothesis. The leaf mites persistently preferred pubescent over glabrous leaf surfaces for oviposition, regardless of the presence of predators. The mites were attracted to cotton fibers on glabrous leaf surfaces, even though there were no direct fitness benefits. When predators co-existed with leaf mites, predation was significantly lower on pubescent leaves than glabrous leaves both in laboratory and in field experiments. These results support the notion that females used complex structures such as trichomes as a cue for oviposition, regardless of host quality or the presence of predators. This suggests that egg-laying females have evolved a simple and conservative preference behavior to increase survival under unpredictable predation stress, even with a fitness cost when predators are absent.