Davacarus lindquisti, Walter, 2004

Walter, David Evans, 2004, From the subantarctic to the subtropics: a revision of the Davacaridae Kethley, 1977 (Acari: Trigynaspida: Mesostigmata) with the description of a new genus and three new species, Journal of Natural History 38 (16), pp. 2033-2049 : 2047-2048

Davacarus lindquisti n. sp.

( figures 1D , 2B , 3C , 9 , 10 )

Material examined. HOLOTYPE: Queensland: adult female, from subtropical rainforest leaf litter and soil, Glow Worm Gully (28‡14’S, 153‡09’E), adjacent to Lamington National Park , Queensland, 27 June 1995, D. E. Walter. In QM . PARATYPES: Queensland: Border Ranges: two males, same data as holotype; Lamington National Park: seven females, three males from subtropical rainforest leaf litter and soil, Darraboola Creek (28‡13’S, 153‡08’E), 23 July 1995 ; female ex subtropical rainforest litter, Moran’s Creek (28‡14’S, 153‡08’E), 27 June 1995, 3 September 1996 ; female ex litter in brush box treehole, Wishing Tree Track , 9 September 1999 . Mt Glorious: Maiala National Park: male ex subtropical rainforest litter, Greene’s Falls , 6 October 1995 ; two males, Love Creek , 5 July 1995 . All D. E. Walter. In UQIC, ANIC, OSAL.

Diagnosis. Yellow-brown davacarid mites with elongate, mostly barbedacuminate dorsal setae; podonotal shield reticulate laterally, micropunctate medially; mesonotal shields each with six setae; pygidial shield with seven setae; sternal shield of female with three pairs of setae; internal malae simple. Endogynium with lung-shaped punctate regions and branched, toothed sclerites. Male genital setae present.

Adult female. Yellowish in life, body 390–450 M m long, primary shields ( figure 9A ) with reticulate to smoothly micropunctate ornamentation and elongate, barbed setae, each far exceeding insertion of next seta in series; secondary sclerotization leathery and micropunctate. Podonotal shield ( figure 9A ) reticulate laterally, smoothly micropunctate medially, with 12 pairs of setae; mesonotal shields (80 across) reticulate, each with six setae; pygidial shield (81–103 across) weakly reticulate laterally, micropunctate medially, bearing seven setae; marginal setae numerous, barbed, inserted on small plates or in leathery cuticle; lateral marginal setae simple to sparsely barbed. Peritrematal shields fused to parapodal shields at level of coxae IV, uniting anteriorly, and bearing two pairs of setae (j1, z1); peritreme reaching to mid-coxa II. Sternal shield ( figures 2B , 10A ) bearing three pairs (s2–4) of setae, st4 (50–51) barbed, st2–3 (28–31) simple; st1 (44–57) strongly barbed, on small platelets. Tritosternum (70–75), base (25–28) with distal collar, laciniae fused basally (stalk~18–20, free portion~26–28) and divided distally. Ventrianal shield (118–140 across) reticulate to smoothly micropunctate, bearing five pairs of simple to barbed setae (50–66 long); metapodal shields reticulate. Opisthosomal gland openings 5–8 across. Mesogynial shield subtrapezoidal, with micropunctate ornamentation; latigynial region with two pairs of setae (st5, 6) on weakly defined shields. Second cheliceral article (93–101 long) with fixed digit bearing gabelzahn and row of 12–15 teeth ( figure 9C ); movable digit (37–41 long) with row of 11–15 blunt teeth, and separate distal tooth; ventral excrescence (28–33 long) strongly fimbriate; lateral lobe with row of fleshy teeth. Subcapitulum ( figure 9D ) with two pairs of rows of genal teeth forming an obtuse angle, deutosternal gutter obsolete; corniculi (18–22) inserted dorsally; palpcoxal seta (27–28) and anterior hypostomal seta (19–24) barbed; external (28–33) and internal (33–47) setae simple to sparsely barbed; tectum ( figure 2B ) rounded, denticulate. Leg I (430–453) somewhat shorter than leg IV (475–510). Endogynium ( figure 3C ) with a pair of lung-like processes, each with 25–30 ventral punctae, leading to dorsal teeth united by a bridge medially and a complex of vaginal sclerites with large horn-like median processes with denticulate arms.

Adult male. Similar to female except somewhat smaller (body 410–422 long); sternigenital region ( figure 10B ) with five pairs of sternal setae, st1 barbed, inserted on small sclerites, st2–4 on smoothly micropunctate sternogenital sclerite, st 5 in soft cuticle; genital valves at level of coxae III–IV, anterior valve (33– 40 across) subcircular, micropunctate, bearing two simple setae; posterior valve crescentic.

Etymology. This species is named in honour of Dr Evert Lindquist in recognition of his tremendous contributions to the study of the Mesostigmata .

Remarks. This species has the least strongly expressed secondary sclerotization in the family and the four primary dorsal plates are clear in even fully sclerotized specimens.

Figures

FIG. 1. (A–C) Acanthodavacarus klompeni, n. sp. (A) Chelicerae from antero-ventral view (arrow points to cheliceral lobe); (B) chelicerae and tectum from lateral view (arrow points to cheliceral lobe); (C) subcapitulum and tritosternum. (D) Davacarus lindquisti, n. sp., subcapitulum and tritosternum.

FIG. 2. (A, C, D) Acanthodavacarus klompeni, n. sp. (A) Female sterno-genital region with intercoxal setae labelled; (C) dorsum of adult female (scale bar: 100Mm); (D) close-up of opisthosomal glands with exudates. (B) Davacarus lindquisti, n. sp., female sternogenital region with intercoxal setae labelled.

FIG. 3. Endogynial complexes of (A) Davacarus gressetti Hunter; (B) Davacarus reginaldi, n. sp.; (C) Davacarus lindquisti, n. sp.

FIG. 9. Davacarus lindquisti, n. sp., female. (A) Dorsum; (B) tectum; (C) chelicera; (D) subcapitulum. Scale bars: 100 Mm (A); 50 Mm (B–D).

FIG. 10. Davacarus lindquisti, n. sp. (A) Venter of female; (B) venter of male. Scale bar: 100 Mm).