larvae are parasites that feed on hemolymph, though deutonymphs and adults are predatory and largely neutral as they feed on small invertebrates in nests
Larva: Prodorsal region with 2 pairs of trichobothria and 1 pair of eyes (Fig. 1). Cheliceral base flasklike in outline (dorsal aspect) (Fig. 1). Palpgenu and palpfemur with 1 seta each (Fig. 1). Urstigmata absent between coxal plates I-II (Fig. 2). Coxal plates I-II well-separated (Fig. 2), coxal plates II-III with 1 seta each (Fig. 2). Anus absent (Fig. 2). Genua II, III with less than 11 barbed setae each (Fig. 2). No trichobothria on genu, tibia, and tarsus I (Fig. 1). Tibia I with 2 solenidia (Fig. 1).
Cosmopolitan. Species parasitizing bees have been found in the Nearctic, Neotropical, and Australian regions.
Bee hosts include the European honey bee (Apis mellifera) and a colletid, Leioproctus
associated exclusively with bees or their close relative, wasps; cannot live without these hosts
some life stages are associated with bees, while others are not
can complete entire life cycle without bees or their close relative, wasps
Mites belonging to the large and cosmopolitan genus Leptus are parasitic as larvae and use a wide range of arthropods to feed. Most common hosts are arachnids (commonly spiders and opiliones) and various orders of insects. Many species are not host specific, attacking an array of disparate hosts (including bees). Mite larvae pierce the cuticle of the host and ingest hemolymph and interstitial fluids via a stylostome, which acts as a proteinaceous drinking straw. After engorging, larvae drop off the host and transform into octopod nymphs and then adults. Both adults and deutonymphs are free-living predators of small invertebrates.
Only two described species are known to attack bees: Leptus ariel, from honey bee Apis mellifera in Guatemala, and Leptus monteithi, from the colletid bee Leioproctus sp. in Tasmania (Southcott, 1989; Southcott, 1993). In addition, several unidentified species have been recorded parasitizing European honey bees in the USA, Peru, Colombia, and Brazil (Fletchtmann, 1980; Losada, 1947; Teixeira, 2011; Wilson et al., 1990; Wilson et al., 1987)