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Stevelus

Harmfulness rating

HARMFUL | NOT HARMFUL | UNCERTAIN

presumably lives in bee nests and disperses on adult bees; details of biology unknown

Name

Stevelus Hunter, 1963Hunter, 1963:
Hunter, P. E. 1963. Two genera of mites associated with stingless bees (Acarina: Laelaptidae). Acarologia. 5:5-12.

Taxonomy

Superorder Parasitiformes » Order Mesostigmata » Suborder Monogynaspida » Hyporder Dermanyssiae » Family Laelapidae » Genus Stevelus

Type species

Stevelus amiculus Hunter, 1963Hunter, 1963:
Hunter, P. E. 1963. Two genera of mites associated with stingless bees (Acarina: Laelaptidae). Acarologia. 5:5-12.

Diagnosis

Female: Idiosomal shield short, not covering posterior body (Fig. 1). PeritremesPeritreme:
Paired, tubular, elaborated extensions of a tracheal system associated with stigmatic openings. Can be chambered, arch-like, and situated on the bases of chelicerae as in Cheyletidae (Prostigmata) or, in Mesostigmata, linear and situated on the lateral sides of the body.
wide, wider than stigma (Figs. 1, 5). AmbulacraAmbulacrum:
The claws and empodium of the apotele or pretarsus.
 elongated (Fig. 2, 11). Claws reduced (Fig. 11). CorniculiCorniculus:
Paired, horn-like process (sometimes toothed, bifurcate, trifurcate, spine-like, spatulate, or membranous) on the subcapitulum of parasitiform mites. These processes usually support the salivary styli. If toothed could be confused with a rutellum, a possibly homologous structure in Acariformes and Opilioacarida.
membranous (Fig. 6). Ventral gnathosomal setae (hypostomatic and palpcoxal) short, spiniform (Fig. 6).

Other diagnostic characters

Female: PeritremesPeritreme:
Paired, tubular, elaborated extensions of a tracheal system associated with stigmatic openings. Can be chambered, arch-like, and situated on the bases of chelicerae as in Cheyletidae (Prostigmata) or, in Mesostigmata, linear and situated on the lateral sides of the body.
not extending beyond legs II (Figs. 1, 5). Tectumtectum:
The leading dorsal, shelf-like projection of the basis capitulum in Mesostigmata. Also known as gnathotectum or epistome.
well-sclerotized (Figs. 1, 9). Anal shieldanal shield:
In Mesostigmata, a ventral shield bearing the anal opening and circumanal setae (adanal or postanal setae), but without any ventral setae or pores (lyrifissures) on it. If ventral setae are present on shield than referred to as a ventrianal shield.
transversely oval (nearly circular); not elongated longitudinally or triangular (Fig. 10).

Species identification

This genus is known from a single species, Stevelus amiculus.

Distribution

Neotropical region (Panama)

Bee hosts

The single known female was collected from the nest of an unidentified stingless bee (Meliponini) (Hunter, 1963Hunter, 1963:
Hunter, P. E. 1963. Two genera of mites associated with stingless bees (Acarina: Laelaptidae). Acarologia. 5:5-12.).

Host association level

permanent permanent:
associated exclusively with bees or their close relative, wasps; cannot live without these hosts
(assumed)

Host associations, feeding, and dispersal

  • All stages presumably live in nests of bees.
  • Females presumably disperse on adult bees.
Fig. 1. Stevelus amiculus holotype female, dorsal view.

Fig. 1. Stevelus amiculus holotype female, dorsal view.
Fig. 2. Stevelus amiculus holotype female, ventral view.

Fig. 2. Stevelus amiculus holotype female, ventral view.
Fig. 3. Sternal shield of Stevelus amiculus holotype female, ventral view.

Fig. 3. Sternal shield of Stevelus amiculus holotype female, ventral view.
Fig. 4. Stevelus amiculus holotype female epigynal shield, ventral view.

Fig. 4. Stevelus amiculus holotype female epigynal shield, ventral view.
Fig. 5. Stevelus amiculus holotype female peritreme, ventral view.

Fig. 5. Stevelus amiculus holotype female peritreme, ventral view.
Fig. 6. Stevelus amiculus holotype female gnathosoma, ventral view; DIC.

Fig. 6. Stevelus amiculus holotype female gnathosoma, ventral view; DIC.
Fig. 7. Stevelus amiculus holotype female gnathosoma, ventral view; phase contrast.

Fig. 7. Stevelus amiculus holotype female gnathosoma, ventral view; phase contrast.
Fig. 8. Stevelus amiculus holotype female chelicerae movable digits, ventral view.

Fig. 8. Stevelus amiculus holotype female chelicerae movable digits, ventral view.
Fig. 9. Stevelus amiculus holotype female dorsal gnathosoma showing tectum.

Fig. 9. Stevelus amiculus holotype female dorsal gnathosoma showing tectum.
Fig. 10. Stevelus amiculus holotype female anal shield.

Fig. 10. Stevelus amiculus holotype female anal shield.
Fig. 11. Stevelus amiculus holotype female ambulacrum I, dorsal view. Ventral view shown in inset.

Fig. 11. Stevelus amiculus holotype female ambulacrum I, dorsal view. Ventral view shown in inset.