Acarophagous Beetles Associated with Oligonychus yothersi (Acari: Tetranychidae) in Avocado Orchards: Life-History Traits and Responses to Infested-Plant Volatiles and Prey-Derived Odours
TL;DR
Although the intrinsic rate of increase was lower for the beetles than for the red mite, the combined population parameters suggest that both predators could still produce substantial offspring per generation over the long term once established.
Abstract
Simple Summary The beetles Parastethorus histrio and Oligota pygmaea (Insecta: Coccinellidae, Staphylinidae) are found in avocado orchards infested with Oligonychus yothersi, yet little is known about their biology and behaviour. We investigated the biological characteristics and life-table parameters of both predatory beetles. They completed the life cycle when reared on colonies of O. yothersi (red mite) and showed higher net reproductive rates (R0) than the red mite. Although the intrinsic rate of increase (rm) was lower for the beetles than for the red mite, the combined population parameters suggest that both predators could still produce substantial offspring per generation over the long term once established. Furthermore, beetles of both species were attracted to herbivore-induced plant volatiles (HIPVs) emitted by avocado shoots infested with O. yothersi. In contrast to O. pygmaea, P. histrio displayed no positive response to odours associated with live prey or prey residues. These findings suggest that both predators may have a strong capacity to locate their prey and establish themselves within red mite colonies.