Bee

Mite ID

Adult: Dorsal shield entire (Figs. 1, 3); setae z3 present (Fig. 3). Most setae in R-series situated on dorsal shield (Fig. 3) and not on unsclerotized cuticle.

Female: Fixed cheliceral digit with pilus dentilis modified to a membranous lobe (Figs. 11, 12, 13). Movable cheliceral digit with a pointed process (mucro) on its mid-ventral face; in bumble bee associated mites mucro situated on external side of movable digit (Fig. 12). Peritrematic shield of adults free posteriorly from exopodal plate IV (Fig. 8). Metasternal shields present (Figs. 4, 6). Epigynal shield gently rounded posteriorly (Figs. 5, 6). Anal shield oval or elliptical, bearing only the 3 anal setae (Fig. 7) (some taxa may have opisthogastric setae on anal shield).

A dichotomous key is not available for all species. The most recent key can be found in Karg, 1988. A key to species associated with bumble bees in North America is available from the bee-associated mites website.

Cosmopolitan. Species permanently associated with bumble bees have been recorded in the Palaearctic and Neotropical regions. Many species in this group have broad, intercontinental distributions.

bumble bees (Bombus) and honey bees (Apis)

facultative (generalist species) or permanent (bumble bee-associated species)

Generalist species (e.g., Proctolaelaps pygmaeus and P. bickleyi)

• All stages are probably omnivorous on microarthropods and fungi in different habitats, including honey bee hives and, rarely, bumble bee nests. They may also feed on eggs, larvae, and pupae of larger insects, thus posing a potential danger to bees.
• Mites probably enter bee nests by walking if a nest is nearby. Dispersal on bees is also possible, but not documented.

Bumble bee-specialist species (Proctolaelaps bombophilus, P. longanalis, P. longisetosus, P. ornatus, and P. sibiriensis)

• All stages live in bumble bee nests. Feeding habit is unknown, but may be different from that of the generalist species.
• Mite females disperse and overwinter on adult queen bees.

This genus includes nearly 100 species with diverse ecologies. They are common inhabitants in beetle galleries, ant colonies, bumble bee nests, stored products, insect cultures, rotting fruit, flowers, and soil.

Among Proctolaelaps, there is a group of species recorded only from bumble bee nests (Proctolaelaps bombophilus, P. longanalis, P. longisetosus, P. ornatus, and P. sibiriensis). In contrast to most generalist species of Proctolaelaps with multidentate fixed chelicerate digits, the bumble bee species display fixed chelicerate digits with just a few teeth, and they lack the typical ventral process (mucro) on the movable digit. The disparity in cheliceral morphology may suggest a different type of and/or more specialized feeding.

Other species associated with bees include habitat generalists Proctolaelaps pygmaeus found in nests of bumble bees and honey bees and Proctolaelaps bickleyi found, among other habitats, in honey bee hives. In addition, one species, Proctolaelaps scolyti, normally associated with bark beetles, has been recorded from Apis mellifera.

Proctolaelaps pygmaeus is an example of a cosmopolitan habitat generalist that can be found in soil, decomposing plant material, bulbs, moss, stored food, under bark, and nests of small mammals, bumble bees, and honey bees. This species may be predatory on small arthropods, but is also a fungivore, and unlike most similar mites, it is able to ingest solid matter (fungal conidia, arthrospores, hyphae, or yeast). There is circumstantial evidence that it can attack humans and that the results can be severe enough to cause extensive papular dermatosis (reviewed by Halliday, 1997). Feeding on both animal prey (small mites) and fungi has been confirmed in laboratory experiments for Proctolaelaps bulbosus (Galvao et al., 2011). Proctolaelaps regalis, which is normally an omnivore species that feeds on fungi and microarthropods, could also prey on eggs, larvae, and pupae of Drosophila by rapid cheliceral thrusting (Houck et al., 1991).

Other species are more specialized. For example, feeding on nectar of tropical flowers and dispersing on hummingbirds, butterflies, or honey possums has been seen (Dusbabek et al., 2007; Guerra et al., 2010). Proctolaelaps nauphoetae is a true parasite of the cockroach Nauphoeta cinerea (Blattidae); it inserts its chelicerae through the cuticle of its host and feeds on the hemolymph.