Gaeolaelaps cubaensis, Joharchi & Halliday & Tolstikov & Trach, 2019

Joharchi, Omid, Halliday, Bruce, Tolstikov, Andrei V. & Trach, Viacheslav A., 2019, New records and new species of mites from Cuba, with description of a new genus of Laelapidae (Acari: Mesostigmata), Zootaxa 4612 (3), pp. 326-350 : 339-347

Gaeolaelaps cubaensis sp. nov.

( Figures 53–67 )

Diagnosis (female). Idiosoma 358–363. Dorsal shield with 39 pairs of long setae including two pairs of Zx setae, and two unpaired setae Jx, setae mostly subequal in length, length 38–50, reaching well past base of next posterior setae, J4, J5 and Z5 with 2–3 minute barbs in apical third length. Pre-sternal area granulated and unsclerotised, without lineate reticulation ( Figures 54 , 59 ). Sternal shield with almost smooth, straight posterior margin; with two pairs of simple and subequal sternal setae, st1 off the shield ( Figures 54 , 59 ), ratio of shield length/width (at broadest level) ≈1. Genital shield longer than wide, ratio of length/width (at broadest level) ≈ 2.7. Anal shield ratio of length/width (at broadest level) ≈ 1; circum-anal setae and post-anal seta smooth. Opisthogastric membrane with nine pairs of smooth setae. Peritremes long, reaching to posterior level of coxae I. Tarsus IV with six elongate setae pd2–3, al2–3 and ad2–3 ( Figure 67 ).

Description. Female (n = 3)

Dorsal idiosoma. Dorsal shield oval shaped, 358–363 long, 176–184 wide, covering entire idiosoma; shield with weak reticulation, more distinct in opisthonotal and lateral regions ( Figures 53 , 58 ). Shield with 39 pairs of long setae, 22 pairs on podonotal region (j1–6; z1–6; s1–6; r2–5) and 17 pairs on opisthonotal region (J1–5; Z1–5; S1–5; and two pairs of Zx), two supernumerary setae Jx between J -series present, all setae on shield uniform in length (38–50) and thickness except j1, z1 (20–25), most setae long enough to reach past base of next posterior seta. Some setae (J4, J5 and Z5) on podonotal region with 2–3 minute barbs. Shield with 14 pairs of discernible pore-like structures, seven on podonotum (id1, id4, gd2, gd4, gd5, gd6, is1) and seven on opisthonotum (idm3, idm4, idm5, gd8, gd9, idl1, idx) ( Figures 53 , 58 ).

Ventral idiosoma ( Figures 54 , 59 ). Tritosternum with long paired pilose laciniae (72–77), columnar base 23–25 × 6–8 wide; pre-sternal area granulated and unsclerotised, without lineate reticulation ( Figures 54 , 59 ). Sternal shield (length 93–100) narrowest between coxae II (68–75), widest between coxa II–III (92–100), with almost straight posterior margin; with two pairs of simple and subequal sternal setae, st1 outside the shield, st 1 25–30, st 2 30–33, st3 33–36, and two pairs of poroids, iv1 slit-like and iv2 sub-oval, adjacent to anterior margin and between st2 and st3 respectively; shield without any distinct reticulation, almost completely smooth ( Figures 54 , 59 ); lateral margins alongside coxa II–III fused with endopodal plates. Metasternal platelets absent, one pair of simple metasternal setae st4 (25–30) and pore-like iv3 inserted in soft cuticle posterior to sternal shield; endopodal plates III/IV elongate, narrow, curved and free from sternal shield. Genital shield elongate, rounded posteriorly, width 52–56, length 150–155. Surface with inverted V-shaped line in anterior half and a few irregular diagonal lines in posterior half, shield bearing smooth genital setae st 5 (19–22) on its edges ( Figures 54 , 59 ). Paragenital poroids (iv5) located on soft cuticle lateral to shield near Zv1. Anal shield subtriangular with rounded anterior margin, length 53–55, width 50–53, bearing three sub-equal, simple and smooth circumanal setae, post-anal setae (17–19), and a pair of para-anal setae (19–21), its anterior half with lineate ornamentation and a pair of lateral pores (gv3); cribrum small. Soft opisthogastric cuticle surrounding genital and anal shields with one pair of sub-oval metapodal plates (13–15 long × 7–9 wide) and nine pairs of setae (Jv1–Jv5, Zv1–Zv 4); all setae uniform in length (14–21) and thickness ( Figures 54 , 59 ). Peritreme long, extending to posterior of coxa I (near s1), peritrematal shield narrow, free from exopodal shields, each shield bearing three discernible pore-like structures, a lyrifissure ip at level of coxa II, one lyrifissure ip and a gland pore gp on post-stigmatic section and also a small pore-like structure within peritreme at level of coxa III; anterior part of shield fused with dorsal shield.

Gnathosoma ( Figures 55–57 and 60–63 ). Hypostome with three pairs of hypostomal setae, h 1 20–22, h 2 15–18, h 3 25–28, and a pair of palpcoxal setae (pc) (25–28). Deutosternal groove wide, with six transverse rows of 15–21 tiny denticles, corniculi horn-like and parallel to each other, almost reaching mid-level of palp femur ( Figures 55 , 61 ). Palp chaetotaxy normal: trochanter 2, femur 5, genu 6, tibia 14, tarsus 15, all setae smooth and needle-like except al1 and al1–2 on palp femur and genu apically spatulate ( Figure 63 ); palp tarsal claw two-tined ( Figure 63 ). Internal malae fringed, with one pair of thin contiguous median projections reaching anterior apex of corniculi, and one pair of thicker lateral projections; labrum considerably longer than internal malae ( Figures 55 and 61 ). Anterior margin of epistome densely denticulate ( Figures 56 and 60 ). Fixed digit of chelicera with nine teeth of varying sizes, a setaceous pilus dentilis, dorsal cheliceral setae short. Arthrodial brush present at base of movable digit, movable digit with two teeth ( Figures 57 , 62 ).

Legs ( Figures 64–67 ).Tarsi I–IV each with a pair of claws and pulvillus. Legs II (274–284) and III (234–250) shorter than legs I (359–367) and IV (364–370). Chaetotaxy normal for free-living Laelapidae : Leg I ( Figure 64 ): coxa 0 0/1 0/1 0, trochanter 1 0/2 1/1 1, femur 2 2/1 3/3 2 (pv1 longer, 33–35), genu 2 3/2 3/1 2 (pl1 and pl2 longer, 21–25), tibia 2 3/2 3/1 2 (av1, pv and lateral setae longer, 28–33). Leg II ( Figure 65 ): coxa 0 0/1 0/1 0, trochanter 1 0/1 1/1 1 (ad1 and av thickened and al1 longer), femur 2 3/1 2/2 1 (pd1 longer and al2 thickened), genu 2 2/1 2/1 2 (av thickened), tibia 2 2/1 2/1 2 (ventral setae thickened). Leg III ( Figure 66 ): coxa 0 0/1 0/ 1 0, trochanter 1 1/1 0/2 1, femur 1 2/1 1/0 1 (pd and pl thickened), genu 2 2/1 2/1 1 (al1, al2 and ad2 longer than other dorsal and lateral setae, 28–33, ventral setae thickened), tibia 2 1/1 2/1 1 (al1, al2 and ad2 longer, 28–33, ventral setae thickened). Leg IV ( Figure 67 ): coxa 0 0/1 0/0 0, trochanter 1 1/1 0/1 1, femur 1 2/1 1/0 1 (al and ad1-2 longer, 40–45, pd strongly thickened), genu 2 2/1 3/0 1, tibia 2 1/1 3/1 2 (ventral setae strongly thickened). All setae fine and needle-like unless otherwise noted. Tarsi II–IV with 18 setae 3 3/2 3/2 3 + mv, md, all setae simple and needle-like; setae mv, av2 on tarsus of leg II and all other ventral setae on tarsus III–IV slightly thickened; setae pd2–3 (48–56), al2–3 (44–48) and ad2–3 (45–47) on tarsus IV longer than the other setae on this segment. All pre-tarsi with a well-developed ambulacral stalk, a pair of claws and three rounded pulvillar lobes, projecting well beyond claws.

Insemination structures: Not seen, apparently unsclerotised.

Male. Unknown.

Type material. Holotype, female, Cuba, north of Matanzas Province, from soil and litter . Paratypes: two females, same data as holotype.

Type deposition. The holotype and one paratype are deposited at the acarological collection of the Tyumen State University Museum of Zoology , Tyumen, Russia ( TUMZ) and also one paratype is deposited at the departamento de Biología Animal y Humana, Facultad de Biología , Universidad de La Habana, Cuba .

Etymology. The specific name is derived from the type locality.

Differential diagnosis. According to Beaulieu (2009) and Kazemi et al. (2014), seta st1 is outside the sternal shield in the presternal region in only a few species of Gaeolaelaps – G. aculeiferoides ( Teng, 1982) , G. debilis ( Ma, 1996) , G. krantzi ( Arutunian, 1993) , G. minor ( Costa, 1968) , and G. franzi ( Van Aswegen & Loots, 1970) . Gaeolaelaps cubaensis can be easily distinguished from all those species by its very long dorsal setae (most long enough to reach past base of next posterior seta in Gaeolaelaps cubaensis , but never reaching base of next posterior seta in the other species), and by its much smaller body size in comparison with other described species in this genus.

In the classification of Karg (1982), G. cubaensis falls into the schusteri species group of Hypoaspis (Gaeolaelaps) , because its genital shield is of normal size and shape and moderately separated from the anal shield, the posterior margin of the sternal shield is straight, the anal shield is wider than the genital shield, and the dorsal shield setae are long. These character states are shared with G. spiculifera ( Berlese, 1918) , from South Africa. Van Aswegen & Loots (1970) show the epistome of G. spiculifera as smooth, with only two anterior points, while that of G. cubaensis is strongly polydentate.

Figures

FIGURES 53–57. Gaeolaelaps cubaensis sp. nov., female. 53, dorsal idiosoma; 54, ventral idiosoma; 55, subcapitulum; 56, epistome; 57, chelicera.

FIGURES 58–63. DIC micrographs of Gaeolaelaps cubaensis sp. nov., female. 58, idiosoma in dorsal view; 59, idiosoma in ventral view; 60, epistome; 61, subcapitulum; 62, chelicera; 63, palp and tarsal claw.

FIGURE 64–67. Gaeolaelaps cubaensis sp. nov., female. 64, leg I (trochanter-tibia); 65, leg II; 66, leg III; 67, leg IV.