Cosmolaelaps lutosus, Khan & Halliday & Bashir, 2024

Khan, Ahmad Kamran, Halliday, Bruce & Bashir, Muhammad Hamid, 2024, New records of soil mites from Pakistan, with description of a new species (Acari: Laelapidae), Persian Journal of Acarology 13, pp. 719-732 : 720-723

Cosmolaelaps lutosus sp. nov. ( Figs. 1–12 )

http://zoobank.org/ urn:lsid:zoobank.org:act:E05ECFC0-1C14-4D72-8720-512F362ABF81

Specimens examined – Holotype female, University of Agriculture , Faisalabad, Punjab, Pakistan, 31° 26' N, 73° 04' E, 20 August 2014, soil core . Paratypes: 3 females, same data as holotype except 21 October 2014 ; 1 female, Dhannot , District Lodhran, Punjab, Pakistan, 29° 36' N, 71° 45' E, 21 June 2014 , soil core; 1 female, Dhudial , Chakwal, Pakistan, 33° 03' N, 72° 57' E, 19 February 2014 , soil core.

Female

Dorsal idiosoma ( Fig. 1 ) – Female with doral shield tapering posteriorly, lightly sclerotised, pale yellow, not completely covering dorsal idiosoma; length 506 µm, width 294 µm, surface with faint polygonal ornamentation thoughout, with adhering fragments of soil and debris, and approximately 12 pairs of minute circular pores and two pairs of lyrifissures. Podonotal region with 23 pairs of setae, opisthonotal region with 17 pairs of setae including Zx1 and Zx2 between the J and Z setae. Three of the six specimens examined have single unpaired Jx seta between J3 and J4. Seta z1 fine, pointed, pilose, J5 pointed, lightly pilose, all other setae distally expanded and pilose ( Fig. 2 ). Setae j3, j4, r3 longest (40–50 μm), z1 and J5 shortest (20–30 μm), others intermediate (30–40 μm). Opisthonotal soft cuticle with seven pairs of setae, three anterior pairs fine, four posterior pairs heavy and strongly pilose.

Ventral idiosoma ( Fig. 3 ) – Tritosterum with trapezoidal base, pre-sternal area with transverse lineate ornamentation. Sternal shield with curved anterior margin and weakly concave posterior margin, with weak polygonal ornamentation, lateral corners fused with endopodal plates II/III, with three pairs of subequal smooth needle-like setae, st1 on anterior margin of shield, and two pairs of lyrifissures. Metasternal setae st4 and metasternal pore inserted in soft integument. Endopodal plates III/IV long, narrow, crescentic. Genital shield elongate, narrowest between coxa IV, weakly ornamented laterally and posteriorly, with one pair of smooth pointed setae. Anal shield longer than wide, with weak ornamentation laterally and smooth posteriorly, cribrum extending anteriorly past post-anal seta, post-anal seta thick and distally pilose, para-anal setae smooth and pointed; pore gv3 on edges of shield, at posterior level of anus. Peritrematal shield very long and narrow except for a short section outside the peritreme opposite coxae II–III bearing a gland pore and a poroid; anterior end reaching z1, post-stigmatal section of peritrematal shield narrow, reaching mid-level of coxa IV; with one pre-stigmatic pore and two post-stigmatic pores. Opisthogastric integument with one pair of elongate metapodal plates and eight pairs of distally pilose setae, their length, thickness, and pilosity increasing posteriorly; opisthogastric pores not visible.

Gnathosoma – Hypostomal setae normal, deutosternal groove with six transverse rows of teeth, each row with about 20 fine teeth ( Fig. 4 ), corniculi robust and horn-like, palp trochanter with two long pointed setae, other features of palp normal for genus. Movable digit of chelicera with two teeth, arthrodial brush with a circular membrane and several long bristles; fixed digit with six small proximal teeth, three distal teeth, and one large tooth near pilus dentilus, pilus dentilis fine and pointed ( Fig. 5 ); epistome semi-circular, serrated, with a long underlying bifurcate process ( Fig. 6 ).

Legs ( Figs. 7–10 ) – Chaetotaxy typical for free-living Laelapidae as reported by Evans (1963): Leg I: coxa 0 0/1 0/1 0, trochanter 1 0/1 1/2 1, femur 2 3/1 2/3 2, genu 2 3/2 3/1 2, tibia 2 3/2 3/1 2. Leg II: coxa 0 0/1 0/1 0, trochanter 1 0/2 0/1 1, femur 2 3/2 2/1 1, genu 2 3/1 2/1 2, tibia 2 2/1 2/1 2, tarsus 3 3/2 3/2 3 + mv, md. Leg III: coxa 0 0/1 0/1 0, trochanter 1 0/2 0/1 1, femur 1 2/1 1/0 1, genu 2 2/1 2/1 1, tibia 2 1/1 2/1 1, tarsus 3 3/2 3/2 3 + mv, md. Leg IV: coxa 0 0/1 0/0 0, trochanter 1 1/0 0/2 1, femur 1 2/1 1/0 1, genu 2 2/1 3/0 1, tibia 2 1/1 3/1 2, tarsus 3 3/2 3/2 3 + mv, md. Most dorsal and ventral setae thick, distally expanded and pilose; seta pv1 on femur II short, thick, spine-like; pl1 and pl2 on tarsus II very thick and conspicuous.

Insemination structures – Not visible in the available specimens.

Etymology The name lutosus (dirty) refers to the fragments of debris adhering to most of the specimens.

Notes

The genus Cosmolaelaps includes 135 species ( Moraes et al. 2022). Attempts to develop a subgenus or species-group classification for these species have been unsatisfactory (for example Karg, 1988). We have checked the descriptions and illustrations of all the species of Cosmolaelaps listed by Moraes et al. (2022), with the exception of a few Berlese species that cannot be recognised. The dorsal shield setae in Cosmolaelaps are modified in various ways – expanded and leaf-like, scimitar-shaped with a basal swelling, terminally trifurcate, or with a longitudinal rib, but only a few species have distally pilose brush-like setae. A few pairs of opisthonotal setae are distally pilose in C. bipennata ( Karg, 2003) and C. brevilingua ( Karg, 2006) but most of the idiosomal setae in these species are smooth and pointed. The only other species that has distal pilosity on most of the dorsal shield setae is C. kassaii ( Van Aswegen & Loots, 1970) . However, C. kassaii has strongly developed exopodal plates, which are absent in C. lutosus . The anal shield of C. kassaii is almost circular, with a small cribrum confined to its posterior margin. In C. lutosus the anal shield is elongate and produced posteriorly, and the arms of the cribrum extend anteriorly beyond the post-anal seta.

Figures

Figures 1–6. Cosmolaelaps lutosus sp. nov. (female) – 1. Dorsal shield; 2. Typical dorsal shield setae (not to scale); 3. Ventral idiosoma; 4. Hypostome; 5. Chelicera; 6. Epistome.

Figures 7–10. Cosmolaelaps lutosus sp. nov. (female) – 7. Leg I, trochanter to tibia; 8. Leg II, trochanter to tarsus; 9. Leg III, trochanter to tarsus; 10. Leg IV, trochanter to tarsus.

Figures 11–12. Ololaelaps translineatus (Barilo, 1991) – 8. Sternal shield; 9. Insemination duct inside coxa IV.