Divilia Sevastianov, 1969

KhaustovK, Alexander A., KhaustovK, Vladimir A. & Klimov K, Pavel B., 2024, A new subcortical mite, Divilia orbiculata n. sp. (Acari: Hemisarcoptidae), from Siberia based on adults and phoretic deutonymphs, Acarologia 64 (1), pp. 123-137 : 124-125

Genus Divilia Sevastianov, 1969

Type species: Divilia oculata Sevastianov, 1969 , by original designation.

Diagnosis — Adults (based on D. orbiculata n. sp.).

Female. Chelicera robust ( Fig. 7A ); movable and fixed digits with two teeth each; paraxial surface with two spiniform cheliceral processes; cheliceral seta (cha) short, needle-like. Subcapitulum with one pair of setae (h); gnathosomal supracoxal setae absent. Palps short; basal palpal segment with only one dorsal seta sup (), ventral seta (a) absent; palpal solenidion very small; palpal eupathidia (ul) not observed. Idiosoma egg-shaped, sejugal furrow weakly developed ( Fig. 6 ). Ocelli present, situated anterolaterad setae si ; prodorsal shield absent; supracoxal setae (scx) filiform, situated laterad small supracoxal sclerite. Idiosoma with 23 pairs of setae: vi, si, se, scx, c 1, c 2, c p, c 3, d 1, d 2, e 1, e 2, f 2, h 1, h 2, h 3, 1a, 3a, 4a, 4b, g, ps 1, and ps 2. Most of hysterosomal setae short, filiform; setae h 3 very long, whip-like. Three pairs of cupules: ia, im and ih ; cupules ip absent. All legs very short, subequal in length, robust (Figs

8, 9); all tarsi lack claws. Legs setation: leg I: Tr 0, Fe 1 (vF), Ge 2(2) (cG, mG, σ′, σ″), Ti 1(1) (dT, φ), Ta 8(4) (d, f, la, wa, ra, p, q, s, ε, ω 1, ω 2, ω 3); leg II: Tr o, Fe 1 (vF), Ge 2(1) (cG, mG,

σ), Ti 1(1) (dT, φ), Ta 8(1) (d, f, la, wa, ra, p, q, s, ω 1); leg III: Tr 0, Fe 0, Ge 0, Ti 1 (kT), Ta 6

(d, r, w, p, q, s); leg IV: Tr 0, Fe 0, Ge 0, Ti 0, Ta 6 (d, r, w, p, q, s). Setae p and q on tarsi I-IV massive, spiniform, distinctly larger than spiniform seta s.

Male. Gnathosoma as in female. Idiosoma smaller and more flattened dorsoventrally than in female. Prodorsum with triangular prodorsal shield ( Fig. 11A ). Setae 4b modified into unpaired sucker; genital setae (g) represented by alveoli. Other character states as in female.

Phoretic deutonymph. Gnathosoma strongly reduced; subcapitulum and palps very short, only gnathosomal solenidia present. Prodorsal sclerite smooth; ocelli and underlying pigment spot well developed. Hysterosomal seta c 1 present. Setae 1a and 3a absent or represented by alveoli; setae 4a, 4b and g filiform. Tarsi I-III with claws. Legs setation: leg I: Tr 0, Fe 1 (vF), Ge 2(1) (cG, mG, σ), Ti 1(1) (dT, φ), Ta 6(3) (d, e, f, la, wa, ra, ε, ω 1, ω 3); leg II: Tr o, Fe 1 (vF), Ge 2(1) (cG, mG, σ), Ti 1(1) (dT, φ), Ta 6(1) (d, e, f, la, wa, ra, ω 1). In Divilia occidentalis and D. exigua , tarsus IV has 4 setae; leg III: Tr 0, Fe 0, Ge 0, Ti 1 (kT), Ta 4 (d, r, w, s); leg IV: Tr 0,

Fe 0, Ge 0, Ti 0, Ta 5 (d, w, r, q, s). Setae d of tarsi I and II foliate distally. Tibia and tarsus IV fused. Setae d and w of tarsus IV very long, whip-like; seta d IV thinner and distinctly longer than w IV ( Fig. 18 ).

Figures

Figure 6 Divilia orbiculata n. sp., female: A – idiosoma in dorsolateral view, B – idiosoma in ventrolateral view.

Figure 7 Divilia orbiculatan. sp., female (A–C) and male (D): A – chelicera, paraxial view, B – supracoxal seta and Grandjean’s organ; C – spermatheca; D – gnathosoma, ventral aspect.

Figure 11 Divilia orbiculatan. sp., male: A – idiosoma in dorsal view, B – idiosoma in ventral view.

Figure 18 Phase contrast micrographs of Divilia orbiculatan. sp., phoretic deutonymph (holotype): A – dorsal view, B – ventral view.