Field Translocation of Mountain Pine Beetles Suggests Phoretic Mite Communities Are Locally Adapted, and Mite Populations Respond Variably to Climate Warming

Temperature is a key determining factor in the population dynamics of forest insects and their associated biota. Bark beetles, often considered key agents of change in forest ecosystems, are particularly affected by warming in their environment. Beetles associate with various phoretic mite species that have direct/indirect effects on beetle fitness and population dynamics, although there is limited knowledge of how temperature affects these communities. Here, we use a field reciprocal translocation experiment with the addition of a novel “warming” environment to represent future changes in local environment in two populations of a keystone bark beetle species (Dendroctonus ponderosae). We hypothesize that mite community abundances as carried by bark beetles are significantly altered when not in their native environments and when subjected to climate warming. We use multivariate generalized linear models based on species abundance data to show that mite community compositions significantly differ across different field climates; and that these patterns diverge between source populations, indicating local adaptation. Our study offers foundational information on the general effects of simulated climate-warming on the compositional shifts of common and abundant biotic associates of mountain pine beetles and may be used as a model system for other important insect–mite systems.

Temperature stress induces mites to help their carrion beetle hosts by eliminating rival blowflies

Ecological conditions are known to change the expression of mutualisms though the causal agents driving such changes remain poorly understood. Here we show that temperature stress modulates the harm threatened by a common enemy, and thereby induces a phoretic mite to become a protective mutualist. Our experiments focus on the interactions between the burying beetle Nicrophorus vespilloides, an associated mite species Poecilochirus carabi and their common enemy, blowflies, when all three species reproduce on the same small vertebrate carrion. We show that mites compete with beetle larvae for food in the absence of blowflies, and reduce beetle reproductive success. However, when blowflies breed on the carrion too, mites enhance beetle reproductive success by eating blowfly eggs. High densities of mites are especially effective at promoting beetle reproductive success at higher and lower natural ranges in temperature, when blowfly larvae are more potent rivals for the limited resources on the carcass.

Phoretic mite Neocypholaelaps indica Evans infests inflorescences of Pachysandra axillari Franch. and its pollinators, Apis cerana Fabricius

In this study, we report that the phoretic flower mite Neocypholaelaps indica can infest flowers of Pachysandra axillaris and Apis cerana in Yunnan, China. We suggest that beekeepers, researchers and regulators should be aware of this species to regulate its potential harm to beekeeping and output of crops in China.

Phoretic uropodine mites (Acari: Mesostigmata) associated with the red palm weevil, Rhynchophorus ferrugineus (Coleoptera: Curculionidae) in Iran

During an investigation on phoretic mite associates of the red palm weevil, <em>Rhynchophorus ferrugineus</em>, in Sistan and Balouchestan Province of Iran, two uropodine species were collected and identified as <em>Centrouropoda almerodai</em> (Uropodidae) and <em>Uroobovella marginata</em> (Dinychidae). This is the first record of the genus <em>Centrouropoda</em> from Iran and the first record of phoretic mites associated with this weevil from the country.