Gaeolaelaps azul, Marticorena & Moreira & Moraes, 2020

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 : 334-338

Gaeolaelaps azul n. sp.

( Figures 1–13 )

Diagnosis (female). Dorsal shield about regularly and lightly reticulate, widest at level of r 3, tapering posteriorly but lobed between S 3 and S 4; with 36 pairs of pointed setae, all of which smooth, except J 4 and Z 5, slightly barbed; setae z 3 and Px 2–3 absent; pores gd 2 and gd 6 absent. Sternal shield reticulate laterally and smooth elsewhere; posterior margin centrally truncate to slightly concave. Genital shield tongue, reticulate. Anal shield subtriangular, marginally reticulate. Opisthogaster with seven pairs of setae (Jv 1– Jv 5, Zv 1 and Zv 2). Peritreme discrete up to midlevel of coxa II (level of s 1 or shortly behind it). Peritrematic plate with a punctate band distal to peritreme, narrow close to it, widening up between j 1 and z 1 to fuse with same structure of opposite side. Anterior region of epistome convex, anterior margin denticulate; covered by about straight lines that converge posteriorly. Deutosternum with six transverse denticulate lines each with 9–22 denticles. Fixed and movable cheliceral digits with respectively five and two teeth.

Adult female. (n=4)

Dorsal idiosoma ( Figs 1, 2 ). Dorsal shield about regularly and lightly reticulate, widest at level of r 3, tapering posteriorly, but lobed between S 3 and S 4; 419 (400–435) long and 156 (143–170) wide; with 36 pairs of pointed setae (j 1– j 6; z 1, z 2, z 4– z 6; s 1– s 6; r 2– r 5; J 1– J 5; Z 1– Z 5; S 1– S 5; setae z 3, Px 2 and Px 3 absent), all of which smooth, except J 4 and Z 5, slightly barbed; with 16 pairs of lyrifissures and five pairs of gland pores. Unsclerotised cuticle laterad of dorsal shield with two pairs of setae ( R 1 and R 5 ). Setal lengths: j 1 26 (22–30), j 2 31 (30–35), j 3 33 (30– 36), j 4 32 (31–33), j 5 26 (24–28), j 6 28 (26–30), z 1 19 (17–21), z 2 31 (30–33), z 4 32 (31–32), z 5 35 (34–35), z 6 28 (25–30), s 1 24 (22–28), s 2 25 (22–28), s 3 32 (30–35), s 4 32 (30–35), s 5 28 (27–30), s 6 30 (29–30), r 2 28 (23–30), r 3 32 (30–35), r 4 27 (25–30), r 5 26 (25–27); J 1 25 (22–27), J 2 26 (25–27), J 3 27 (25–28), J 4 26 (25–27), J 5 25; Z 1 29 (26–31), Z 2 29 (27–30), Z 3 31 (30–32), Z 4 32 (30–35), Z 5 37 (35–37), S 1 27 (25–28), S 2 26 (25–28), S 3 28 (25–30), S 4 29 (27–30), S 5 32 (30–34), R 1 24 (22–25), R 5 27 (25–30).

Ventral idiosoma ( Fig. 3 ). Base of tritosternum 33 (30–36) long and 13 (12–14) wide basally; laciniae 91 (85– 100), separated by about 93% of their total length. With a pair of punctate and transversely striate platelets fused with each other. Sternal shield reticulate laterally and smooth elsewhere; with three pairs of setae (st 1– st 3) and two pairs of lyrifissures (iv 1, iv 2); posterior margin centrally truncate to slightly convex; length 112 (100–120), width 97 (90–102). Distances between setae: st 1– st 1 73 (66–76), st 2– st 2 87 (85–91), st 3– st 3 88 (75–95). Seta st 4 and lyrifissure iv 3 on unsclerotised cuticle. Anterior region of endopodal plate fused with sternal shield; region behind sternal shield represented by a triradiate arched platelet, with short and sharp anterior and lateral projections, and elongate and blunt posterior projection. Exopodal plate fragmented, subtriangular between coxae II–III and III–IV and elongate and arched posterolaterad of coxa IV. Genital shield tongue-like, reticulate, in some specimens with slight constriction behind st 5; 143 (135–150) long, 59 (55–61) wide; distance st 5– st 5 57 (53–61). Genital lyrifissures iv 5 on unsclerotised cuticle laterad of st 5; with a pair of slender paragenital platelets posteriad of st 5. With a pair of ellipsoidal metapodal platelets. Anal shield subtriangular, marginally reticulate, with para-anal cribral extensions consisting of 1–2 rows of spines; with a pair of discreet pores (gv 3) next to a pair of elongate marginal marking. Opisthogaster with seven pairs of simple setae (Jv 1– Jv 5, Zv 1 and Zv 2) and five pairs of lyrifissures. Setal lengths: st 1 33 (30–35), st 2 31(28–35), st 3 31 (29–33), st 4 26 (24–28), st 5 22 (20–24), Jv 1 23 (21–25), Jv 2 24 (22–25), Jv 3 24 (20–26), Jv 4 25 (22–28), Jv 5 37 (35–40), Zv 1 21(20–24) and Zv 2 25 (23–26), para-anal 25 (23–30), postanal 25 (23–27). Setae smooth and pointed, except Jv 5, slightly barbed.

Peritreme and peritrematic plate ( Figs 1, 3 ). Peritreme 178 (175–180) long, extending to level of s 1 or shortly behind it. Peritrematic plate barely distinguishable for most of its extent, widening in region between coxae II–III and near anterolateral notch of dorsal shield (anteriad of r 3), fusing to dorsal shield between z 1 and s 1; with a lyrifissure (anterior) and a pore on each side between coxae II–III and a pair of lyrifissures and a pore behind each stigma; with a punctate band distal to peritreme, narrow close to it, widening up between j 1 and z 1 to fuse with same structure of opposite side.

Gnathosoma ( Figs 4–8 ). Anterior region of epistome convex, anterior margin denticulate; covered by about straight lines that converge posteriorly. Chelicera with dorsal and antiaxial lyrifissure and dorsal seta distinct; fixed cheliceral digit 52 (45–55), with five teeth and setiform pilus dentilis; movable digit 70 (67–74), with two teeth. Labrum extending forward to a level slightly beyond tip of corniculus. Deutosternal groove with six denticulate rows, each with 9–22 denticles; with three smooth transverse lines laterad of deutosternal groove. Corniculi parallel to each other, 41 (40–45) long and 15 (13–17) wide, reaching base of palp femur; h 3 mediad and slightly anteriad of h 2. Internal malae subtriangular, fimbriate. Setal lengths: h 1 33 (28–36), h 2 22 (20–25), h 3 25 (20–30), pc 26 (22–30). Palp 172 (160–190) long; with usual numbers of setae for Mesostigmata ( Evans, 1964) ; all setae smooth; seta al1 of genu 13 (12 –14) stout, bacillate; seta al 2 genu 22 (21 –33) and al 1 of femur 26 (24 –27), spine-like. Palp-tarsal claw with two tines of very distinct lengths.

Spermathecal apparatus ( Fig. 9 ). Tubulus relatively thick, about 3 in diameter; rami distinct, with a slight constriction near attachment to sacculus, about 20 away from each other at attachment.

Legs ( Figs 10–13 ). Lengths (not including ambulacra): I, 472 (465–480); II, 336 (322–345); III, 295 (280–305); IV, 458 (445–470). 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 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. With the following setae stouter than other setae of same segments: legs II and III: av and pv of genu and tibia; mv, av 2, pv 2, md, al 1, pl 1, av 1 and pv 1 of tarsus; leg IV: av of genu; av and pv of tibia; mv, av 2 and pv 2 of tarsus. Setae pd 2 of tarsus IV slender and elongate.

Adult male. unknown.

Type specimens. Holotype female collected at Jataí on 26/II/2014 from litter of a sugarcane field. Three paratype females collected at Valparaíso on 16/XII/2014 from soil (0–5 cm deep) of a sugarcane field.

Remarks. Karg (1979) created the “ angustus species group”, in which he included four species. A few years later, he incorporated another species to the group ( Karg, 1982), but that species was later considered to belong to Cosmolaelaps Berlese ( Moreira et al., 2014). The structures taken into account by Karg (1979) to characterise that species group were the shape of the dorsal shield (tapering behind r 3) and the usual absence of Px setae. The concept of the group was recently modified, while new synonymies were established and some species were transferred to other genera ( Nemati & Kavianpour, 2013; Kazemi et al., 2014; Nemati et al., 2018). Despite the difficulties in determining exactly the constitution of this species group, probably because of the continuous variation of characters among species, narrowing of the dorsal shield posteriorly seems the most consistent character. Within this group, Gaeolaelaps dactylifera ( Fouly & Al-Rehiayani, 2011) , Gaeolaelaps fishtowni ( Ruf & Koehler, 1993) , Gaeolaelaps queenslandicus ( Womersley, 1956) , Gaeolaelaps sevastianovi Trach, 2016 and Gaeolaelaps zhoumanshuae ( Ma, 1997) are most similar to Gaeolaelaps azul n. sp. They all have dorsal shield tapering behind the level of r 3 –r 4 and lack Px 2 and Px 3. However, G. fishtowni and G. queenslandicus differ from the new species by having 6–7 marginal pairs of setae on the unsclerotised cuticle and by having distinctly spur-like setae on legs II and IV; G. sevastianovi has very short peritreme (ending near coxa III) and three pairs of marginal setae on the unsclerotised cuticle; G. zhoumanshuae has a short peritreme (ending near coxa II) and dorsal setae short, none of which extending beyond base of the closest subsequent seta; G. dactylifera has nine pairs of marginal and submarginal setae and smooth dorsal shield. This new species is also similar to Gaeolaelaps mirzakhaniae Khalesi & Kazemi, 2018 , which however has setae Px 2 and Px 3, different ornamentation of the dorsal shield and does not have the punctate strip anteriad of the peritreme.

Etymology. The epithet azul refers to “Azul”, the name of a river near the type locality of this species.

Figures

FIGURES 1–9. Gaeolaelaps azul n.sp. Female: 1, dorsal view of idiosoma; 2, setae; 3, ventral view of idiosoma; 4, epistome; 5, gnathosoma; 6, anti-axial view of chelicera; 7, labrum; 8, pedipalp; 9, spermathecal apparatus.

FIGURES 10–13. Gaeolaelaps azul n.sp. Female: 10, leg I; 11, leg II; 12, leg III; 13, leg IV.