Acalvolia Fain, 1971

Fan, Qing-Hai, George, Sherly & Kumarasinghe, Lalith, 2010, Genus Acalvolia (Acari: Winterschmidtiidae), with the description of a new species from the USA, Zootaxa 2719, pp. 41-61 : 42

Acalvolia Fain, 1971

Acalvolia Fain, 1971 , 84(3–4): 281–284; Fain & Knülle, 1981, 7: 139–140. Type species: Vidia squamata Oudemans, 1909 .

Diagnosis. FEMALE. Ocelli absent; prodorsal shield widened posteriorly; setae sce at least 2× as long as sci; supracoxal setae scx slender, smooth or slightly barbed; opisthosomal cuticle with 1 to 3 pairs of tiny tubercles ( Fig. 1 ); idiosoma with 2 pairs of h setae and 3 pairs of ps setae; tarsi (excluding pretarsi) at least 5× as long as their basal width. Chaetotaxy of legs I–IV: trochanter 1, 1, 1, 0; femora 1, 1, 0, 0; genua 2 + 2σ, 2 + 1σ, 1σ, 0; tibiae 2 + 1ϕ, 2 + 1ϕ, 1 + 1ϕ, 1 + 1ϕ; tarsus I with 4 long setae (wa, ra, la and d) + 2 minute terminal setae (f and e) + 1 subterminal ventral spine (s) + 2 basally merged terminal ventral spines (u + p and v + q) + ω1 + ω2 + ω3 + 1ε; tarsus II similar to tarsus I but without ω2, ω3 and ε; genu I solenidion σ’ less than 2× as long as σ”; σ on genu III nearly reaching base of tibia III; seta wa on tarsi I and II situated closer to la and ra rather than to ω1; seta w on tarsi III and IV situated at same level with or slightly posterior to r rather than far from r.

MALE. Ocelli absent; prodorsal shield, comparative lengths of sce and sci; structure of scx, number of h and ps setae, chaetotaxy of legs I–IV (except tarsi), comparative lengths of σ’ and σ” on genu I, size of σ on genu III and position of w on tarsi III and IV same as in female. Ventral setae 3a and 4a absent. Tarsi I and II (excluding pretarsi) less than 4× as long as their basal width, their apicoventral portion modified into suckers, all setae situated at terminal half; tarsi I–IV with same number of setae as in female but terminal ventral spines u fully merged with p, and v fully merged with q, and subterminal ventral spine (s) on tarsi I and II indiscernible.

Remarks. Fain (1971) established the genus, Acalvolia , based on the deutonymph of Vidia squamata Oudemans, 1909 . Ten years later, Fain & Knülle (1981) described the adult female, adult male, tritonymph, deutonymph, protonymph and larva of Acalvolia squamata , and also provided a detailed definition of adult and deutonymph of the genus.

This genus is very similar to Psylloglyphus but can be separated from the latter by having 1 to 3 pairs of small opisthosomal tubercles, having larger idiosoma length (more than 300 μm) and shorter spermathecal duct (not forming 5 or 6 loops) in female. Adults of this genus can also be readily distinguished from those in other genera of the family by the following combination of characters: ocelli absent, femur IV and genu III without setae; genu III with a dorsal solenidion.

Figures

FIGURE 1. Acalvolia americana sp. nov. (female). Dorsal view of idiosoma.