Rearing Phoretic Mites Associated with Wood-Boring Insects

Phoretic mites are common associates of a wide range of wood-boring insects, such as Coleoptera: Curculionidae and Cerambycidae. Phoretic mites are among the few groups of organisms capable of accessing their hosts' breeding sites. These organisms are minute, establishing close associations and affinity for biotic and abiotic conditions within wood-boring insects' galleries. Their presence within the galleries may exert a significant influence on beetle behavior and reproduction. Some species may act as natural antagonists of the beetles and their mutualistic fungi, disrupting symbiotic relationships that guarantee their success. These characteristics make phoretic mites promising candidates for biological control programs targeting wood-boring pests. However, reproducible methods for rearing these mites are needed to study their basic biology and ecology and assess their potential as biocontrol agents. Despite their importance, there are currently no detailed protocols for maintaining phoretic mite populations in captivity. This study presents a practical and accessible approach for rearing two groups of phoretic mites, fungivores/detritivores (Acari: Astigmata) (i.e., Histiogaster arborsignis) and predators (Acari: Mesostigmata) (i.e., Proctolaelaps spp.). We propose using rolled barley grains and nematodes as nutritional sources for these mites, respectively. These food sources are practical and widely accessible, requiring minimal maintenance while offering a standardized diet tailored to the nutritional requirements of the target mite groups. A plaster-charcoal-based substrate is used as a humidity-regulating matrix. This combination provides both food resources and a suitable microhabitat for long-term maintenance and reproduction of these mites. The method described is scalable, enabling researchers to expand rearing units in proportion to colony size and experimental requirements. This protocol offers a critical tool for advancing research into the ecological roles of phoretic mites. This experimentally validated system ensures long-term colony viability for several months and multiple generations, while remaining adaptable for rearing other mite taxa under laboratory conditions.