Leptus

 

HARMFUL | NOT HARMFUL | UNCERTAIN

larvae are parasites that feed on hemolymph, though deutonymphs and adults are predatory and largely neutral as they feed on small invertebrates in nests

Name and classification

Leptus Latreille, 1796

Taxonomy
Superorder Acariformes » Order Trombidiformes » Suborder Prostigmata » Infraorder Anystina » Hyporder Parasitengona » Family Erythraeidae » Genus Leptus

Type species
Acarus phalangii Gée. Fab" (=Acarus phalangii De Geer, 1778)

Diagnosis

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).

Species identification

This is a species-rich genus with no key available for all species. The two described species attacking bees (Leptus ariel and L. monteithi) can be identified using Southcott, 1989 and Southcott, 1993.

Distribution

Cosmopolitan. Species parasitizing bees have been found in the Nearctic, Neotropical, and Australian regions.

Bee hosts

Bee hosts include the European honey bee (Apis mellifera) and a colletid, Leioproctus

Host association level

Permanent

associated exclusively with bees or their close relative, wasps; cannot live without these hosts

Temporary

some life stages are associated with bees, while others are not

Facultative or opportunistic

can complete entire life cycle without bees or their close relative, wasps

temporary

Host associations, feeding, and dispersal

  • Deutonymphal and adult stages are predatory in different habitats, such as forest litter, and can also be found in bee nests. Protonymphal and tritonymphal stages are not active; they develop under the cuticle of the preceding stage.
  • Mite larvae are parasitic on different arthropod hosts, including bees, though probably with no specificity towards bees. When on bees, they feed on hemolymph and internal tissue fluids and use the bees for transport.
  • After engorging, larvae drop off the host (inside or outside the nest) and molt into nymphs and then adults. Non-larval mite stages may feed on other arthropods in bee nests.

Biology

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)