Gaeolaelaps circularis Hyatt

Marticorena, Jorge L. M., Moreira, Grazielle Furtado & Moraes, Gilberto José De, 2020, Mites of the genus Gaeolaelaps (Acari: Laelapidae) from southern Brazil, with description of two new species, Zootaxa 4772 (2), pp. 333-348 : 343-346

Gaeolaelaps circularis Hyatt

( Figures 34 –46)

Gaeolaelaps circularis Hyatt, 1964: 470 .

Hypoaspis (Geolaelaps) circularis .— Karg, 1979: 84, 1982: 242, 1989: 116.

Gaeolaelaps circularis .— Beaulieu, 2009: 36; Kazemi et al., 2014: 505.

Diagnosis (female). Dorsal shield suboval, laterally reticulate, more extensively behind Z 1, smooth elsewhere, with a slender and rugose strip along margin; with 33 pairs of smooth and pointed setae; setae J 2, Px 2 –Px 3, z 6, Z 2 and S 2 absent; pores gd 1, gd 2 and gd 6 absent. Sternal shield reticulate over most of its extent, smooth posteromesally; with long projection between coxae I–II; posterior margin convex. Genital shield drop-like, reticulate. Anal shield piriform. Opisthogaster with 7–9 pairs of simple setae (Jv 1– Jv 5, Zv 1and Zv 2 always present; Zv 3 and Zv 4 present or absent) and five pairs of lyrifissures. Peritreme reaching mid-level of coxa I (level of s 2), totally ventral. Epistome convex, covered with short, broken, irregularly oriented lines; anterior margin denticulate. Deutosternum with six transverse denticulate lines, each with 12–19 denticles; with three smooth transverse lines laterad of deutosternal groove. Fixed and movable cheliceral digits with eight and two teeth.

Adult female. (n= 6)

Dorsal idiosoma ( Fig. 34 ). Dorsal shield suboval, laterally reticulate, more extensively behind Z 1, smooth elsewhere, with a slender and rugose strip along margin; 489 (485–495) long and 301 (290–314) wide; with 33 pair

of setae: j 1– j 6, z 1– z 5, s 1– s 6, r 2– r 5, J 1, J 3– J 5, Z 1, Z 3– Z 5, S 1, S 3– S 5; all setae smooth and pointed; setae z 6, J 2, Px 2 –Px 3, Z 2 and S 2 absent; with 15 pairs of lyrifissures and three pairs of pores (gd 1, gd 2 and gd 6 absent). Unsclerotised cuticle laterad of dorsal shield with one or two pairs of setae ( R 1 and R 5 ; the latter often absent). Setal lengths: j 1 28 (27–28), j 2 41, j 3 52 (49–55), j 4 53 (47–56), j 5 39 (37–40), j 6 31 (30–32), z 1 15 (15–16), z 2 50 (50–51), z 3 52 (52–53), z 4 56, z 5 35 (33–38), s 1 33 (31–34), s 2 33 (31–35), s 3 52 (52–53), s 4 56 (55–57), s 5 50 (50–51), s 6 39 (37–41), r 2 37 (36–38), r 3 42 (41–43), r 4 30 (30–31), r 5 30; J 1 27 (26–28), J 3 23 (22–25), J 4 20 (20–21), J 5 20 (20–21), Z 1 48 (46–50), Z 3 41 (40–42), Z 4 41 (40–41), Z 5 42 (41–42), S 1 25 (25–26), S 3 31 (30–33), S 4 27 (27–28), S 5 31 (30–32), R 1 20 (18–21), R 5 23 (21–24).

Ventral idiosoma ( Fig 35 ). Base of tritosternum 21 (18–23) long and 11 (10–12) wide basally; laciniae 72 (70– 73), separated for about 95% of their total length. With a pair of reticulate presternal platelets fused to each other by a narrow bridge. Sternal shield reticulate over most of its extent, smooth posteromesally; with long projection between coxae I–II; with three pairs of setae (st 1– st 3) and two pairs of lyrifissures (iv 1, iv 2); posterior margin convex; length 134 (130–145), width 111 (105–116). Distance between setae: st 1– st 1 61 (60–62), st 2– st 2 87 (85–90), st 3– st 3 88 (87–90). Seta st 4 and lyrifissures iv3 on unsclerotised cuticle. Anterior region of endopodal plate fused with sternal shield; region behind sternal shield represented by a triradiate arched platelet, with sharp projection anteriorly (that in some specimens seem fused by a narrow bridge with sternal shield) and laterally, an with an elongate and blunt posterior projection. Exopodal plate fragmented, subtriangular between coxae II–III, elongate and arched near coxae III and IV, the latter with short and sharp anterior and lateral projections, and elongate and blunt posterior projection. Genital shield drop-like, bulging considerably behind st 5; reticulate, 157 (155–160) long, 105 (103–110) of maximal width; distance st 5– st 5 73 (68–80). Genital lyrifissures (iv 5) on unsclerotised cuticle, posterolaterad of st 5. With a pair of elongate metapodal platelets. Anal shield piriforn, with a single line parallel to margin and a pair of marginal pores about in level with anterior margin of anal opening; cribrum with 2–3 rows of spines; glands gv3 indistinguishable. Opisthogaster with 7–9 pairs of simple setae (Jv 1– Jv 5, Zv 1 and Zv 2 always present; Zv 3 and Zv 4 present or absent) and five pairs of lyrifissures. Setal lengths: st 1 43 (41–46), st 2 50, st 3 46 (45–47), st 4 36 (35–39), st 5 36 (35–37), Jv 1 39 (38–40), Jv 2 38 (36–39), Jv 3 34 (32–36), Jv 4 21 (20–21), Jv 5 38 (35–40), Zv 1 22 (21–23), Zv 2 33 (32–35), Zv 3 20, para-anal 36 (35–37), postanal 21 (18–22). All setae smooth and pointed.

Peritreme and peritrematic plate ( Figs 34, 35 ). Peritreme 236 (230–242) long, extending anteriorly to midlevel of coxa I (level of z 2), totally ventral; peritrematic plate fused with dorsal shield near z 1, with a lyrifissure (anterior) and a pore between coxae II–III of each side and a pair of lyrifissures and a pore behind each stigma.

Gnathosoma ( Figs 37–40 ). Anterior region of epistome convex; anterior margin denticulate, covered with short, broken, irregularly oriented lines. Chelicera with distinct dorsal lyrifissure, antiaxial lyrifissure and large dorsal seta and; fixed digit 51 (50–53) long, with 8–9 teeth (most basal and fourth most distal denticles distinctly larger than others) and a thick pilus dentilis; with a distinct triangular notch on the paraxial surface matching the tip of the movable digit; movable digit 61 (59–62) with two teeth. Labrum extending forward well beyond tip of corniculus, by a distance about half as long as the latter. Deutosternal groove with six denticulate rows, each with 10–20 denticles; with three pairs of smooth, transverse lines laterad of deutosternal groove. Corniculi parallel to each other, 36 (35–37) long and 14 (12–16) wide, reaching base of palp femur; h 3 slightly anteromediad of h 2. Internal malae subtriangular, fimbriate, sided by pair of shorter fimbriate structures. Setal lengths: h 1 39 (36–42), h 2 32 (31–33), h 3 51 (48–53), pc 36 (34–39). Palp 161 (160–165) long; with usual numbers of setae for Mesostigmata ( Evans, 1964) ; al 1 of genu 13 (12–15) stout, bacillate; al 2 of genu 24 (22 –25) and al 1 of femur 26 (26 –27), spine-like. Palp-tarsal claw with two tines of distinct length.

Spermathecal apparatus ( Fig. 41 ). Tubulus slender, about 1 µ in diameter; rami distinct, with a constriction near attachment with sacculus, about 34 µ away from each other at attachment to sacculus.

Legs ( Fig. 42–45 ). Lengths (not including ambulacra): I, 452 (440–466); II, 394 (390–397); III, 360 (355–365); IV, 524 (518–535). Chaetotaxy (coxa–tibia): I, 0 0/2 0/0 0; 1 0/1 1/2 1; 2 2/1 3/3 2; 2 3/2 3/1 2; 2 3/2 3/1 2; II -0/1 0/1 0; 1 0/1 0/2 1; 2 3/1 2/2 1; 2 3/1 2/1 2; 2 2/1 2/1 2; III 0 0/1 0/1 0; 1 1/1 0/1 1; 1 2/1 1/0 1; 2 2/1 2/1 1; 2 1/1 2/1 1; IV 0 0/1 0/0 0; 1 1/1 0/1 1; 1 2/1 1/0 1; 2 2/1 3/0 1; 2 1/1 3/1 2; tarsi II–IV with 18 setae each. Seta pd2 of tarsus IV 91 (85–93) and ad1 femur IV 72 (70–75) longer (at least 1.2) than other setae of the same segments. With the following setae stouter than other setae of same segments: leg II: av of femur and genu; av and pv of tibia; mv, ad 2, al 2, md, al 1, pl 1, av 1 and pv 1 of tarsus; leg III: av and pv of genu and tibia; mv, ad 2, al 2, md, av 2, pv 2, al 1, pl 1, av 1 and pv 1 of tarsus; leg IV: ad of trochanter, pv of genu; av and pv of tibia; av 2, pv 2, md, al 1, pl 1, av 1 and pv 1.

Adult male. unknown.

Specimens examined. Four females collected at Valparaíso on 12/II/2014 from soil (0–5 cm deep) of natural vegetation; two females collected at Ipaussu on 28/I/2015 from soil (0–5 cm deep) of natural vegetation.

Remarks. This species was only known from the original description, based on the holotype, taken from a passalid beetle collected in Venezuela. The original description is rather detailed, with good illustrations of the idiosoma, gnathosoma and tarsi II and IV, although bringing only the measurements of the dorsal shield. This species seems most similar to Gaeolaelaps disjunctus ( Hunter & Yeh, 1969) , which differs by having 32 pairs of dorsal shield setae (apparently missing z2). Gaeolaelaps aculeifer ( Canestrini, 1884) can be readily distinguished by hav- ing a much larger number of R setae. This same characteristic can be used to separate Gaeolaelaps variabilis ( Faraji & Halliday, 2009) from G. circularis , in addition to the absence of z3 and the concave posterior margin of the sternal shield in the G. variabilis .

Figures

FIGURES 34–42. Gaeolaelaps circularis n.sp. Female: 34, dorsal view of idiosoma; 35, ventral view of idiosoma; 36, epistome; 37, gnathosoma; 38, anti-axial view of chelicera; 39, labrum; 40, pedipalp; 41, spermathecal apparatus.