Zercoseius luizdequeirozi, Santos & Borges & Castilho, 2023

Santos, Jandir C., Borges, Vinicius & Castilho, Raphael C., 2023, A new species of Zercoseius (Acari: Mesostigmata: Blattisociidae) from Brazil, Zootaxa 5336 (2), pp. 271-280 : 272-278

Zercoseius luizdequeirozi n. sp.

( Figs 1–17 )

Diagnosis (adult female).Epistome with three pointed and smooth anterior projections. Podonotum and opisthonotum totally fused, respectively with 20 and 16 pairs of setae (including all r–R), most of which spine-shaped, smooth and straight to slightly curved; J 2– J 5 and Z 2– Z 4 slightly spatulate and slightly serrate; seta s 1 present; fused dorsal shield strongly sclerotised, completely covering the idiosoma, ornamented mostly by a honeycomb pattern skirted by a tuberculate band, with a pair of narrow and segmented marginal strips extending from the level of r 2 to the level of R 1. Presternal area with a pair of minute plates. Lyrifissures iv 1 and iv 2 each next to a large, crater-like depression. Peritrematic plate broad, fused with exopodal plate next to coxa IV, and fused section posteriorly truncate. Tarsus I with an elongate and curved seta s. Genu and tibia of leg III respectively with nine and eight setae (each including one pl) and tibia of leg II with ten setae (including two pl). Setae ad 2 and pd 2 of tarsi II and III relatively stout and elongate.

Description

Adult female (n = 10).

Gnathosoma. Chelicera with antiaxial and dorsal lyrifissures as well as dorsal seta ( Fig. 1 ); arthrodial process shaped as a short coronet-like fringe; fixed cheliceral digit 27 (25–28) long, with five teeth in addition to the apical hook and a setiform pilus dentilis; movable cheliceral digit 24 (23–25) long, with two teeth in addition to the apical hook. Palp setae (trochanter to genu): 2–5–6; inner palp trochanter seta (av) distinctly longer than outer seta (pv) ( Fig. 2 ); all setae aciculate and smooth. Palptarsal claw 2-tined ( Fig. 3 ). Epistome with three pointed and smooth anterior projections ( Figs 4 and 5 ). Deutosternum relatively wide, delimited by jagged lateral lines, with anteriormost transverse line smooth followed by six transverse denticulate lines, about parallel to each other, each with 4–12 denticles; sub-proximal region of deutosternum not bordered by lines of denticles. Corniculi wellseparated from each other, well-sclerotised, horn-shaped, about 16 (15–17) long from median level of base to tip and 7 (6–7) wide basally. Each internal mala anteriorly rounded. Seta h 3 about in longitudinal line with h 1 and mediad and slightly posteriad h 2. Setal lengths: h 1 24 (18–25), h 2 9 (8–10), h 3 18 (13–20), pc 21 (15–23); palp trochanter setae av 18 (17–20) and pv 9 (8–10); all acicular and smooth.

Dorsal idiosoma ( Fig. 6 ). Podonotal and opisthonotal shields totally fused, forming a single and ellipsoidal dorsal shield, completely covering the idiosoma; 327 (300–355) long and 244 (215–273) wide; shield strongly sclerotised, ornamented mostly by a honeycomb pattern with an outer tuberculate band ( Fig. 7 ), with a pair of narrow and segmented marginal strips extending from the level anteriad r 2 to the level posteriad R 1. Podonotal region with 20 pairs of setae (j 1– j 6, z 2– z 6, s 1, s 3– s 6 and r 2– r5; s 5 absent on the left side in the holotype), four pairs of distinguishable lyrifissures and four pairs of distinguishable pores. Opisthonotal region with 16 pairs of setae (J 1– J 5, Z 1– Z 5, S 1– S 5 and R 1), ten pairs of distinguishable lyrifissures and one pair of distinguishable pores. Unsclerotised cuticle along lateral margins without setae. Setal lengths: j 1 8 (5–10), j 2 21 (20–23), j 3 21 (18–23), j 4 23 (20–28), j 5 23 (20–25), j 6 27 (25–28), J 1 28 (28–30), J 2 30 (30–33), J 3 32 (30–33), J 4 32 (30–33), J 5 32 (31–33), z 2 22 (18–23), z 3 22 (20–23), z 4 23 (23–25), z 5 21 (18–23), z 6 28 (25–30), Z 1 28 (25–30), Z 2 31 (28–33), Z 3 34 (30–38), Z 4 34 (33–38), Z 5 26 (23–28), s 1 13 (10–15), s 3 24 (23–25), s 4 21 (18–25), s 5 24 (23–28), s 6 24 (23–25), S 1 27 (25–30), S 2 27 (28–30), S 3 28 (25–30), S 4 28 (25–30), S 5 23 (20–25), r 2 15 (13–20), r 3 13 (10–15), r 4 17 (13–20), r 5 17 (15–20), R 1 9 (8–10). Most dorsal setae spine-shaped, smooth and straight to slightly curved; J 2– J 5 and Z 2– Z 4 slightly spatulate and slightly serrate ( Fig. 8 ). Setae J 1– J 3 about as long as distance between their bases. Setae set on tubercles, except j 1 and R 1.

Ventral idiosoma ( Fig. 9 ). Base of tritosternum 10 (8–10) long and 15 (13–23) wide proximally; laciniae 48 (43–50) long, separated for about 80% of their total length, pilose along divided section. Presternal area with a pair of minute plates. Sternal shield 82 (78–85) long and 114 (108–128) wide, bearing setae st 1– st 3 and lyrifissures iv 1 and iv 2; ornamented with relatively few crater-like elements that are much larger next to region usually occupied by iv 1 and iv 2 (inconspicuous lyrifissures in these mites) ( Fig. 10 ); the margin of the crater-like element near each iv 1 is only conspicuous as a short, curved band along the anterior section, whereas the margin of the crater-like element near each iv 2 is conspicuous as a horseshoe-shaped band; with a large, anteromedian subtriangular depression, whose anterior angles coincide with insertions of setae st 1 and posterior angle is slightly anteriad transverse line connecting bases of setae st 2. With a pair of distinct subtriangular metasternal plates, each bearing seta st 4 and lyrifissure iv 3. Epigynal shield trapezoidal, ornamented with crater-like elements and a pair of irregular lines parallel to the lateral margin; hyaline anterior region rounded; posterior margin truncate; broadened posteriorly to encompass seta st 5 and lyrifissure iv 5, distance st 5– st 5 76 (73–80). Ventrianal shield bowl-shaped, ornamented with crater-like elements throughout and with anterolateral reticulation or oblique striation; 102 (93–118) long and 212 (200–230) wide; with seven pairs of setae (Jv 1– Jv 5, Zv 2 and Zv 3) in addition to circumanal setae; para-anal and post-anal setae similar in length, para-anals inserted between levels of anterior margin and mid-length of anal opening; anal opening relatively small; gv 3 indistinguishable. Without opisthogastric setae on unsclerotised cuticle. Metapodal plates seemingly amalgamated with ventrianal shield.Anterior section of endopodal strip fused with sternal shield; section between coxae III–IV represented by a pair of distinct subtriangular fragments, each with a conspicuous crater-like element. Exopodal plate distinguishable as two discrete subtriangular plates between coxae I–II and II–III abutting a narrow, sclerotised strip running along the inner margin of the peritreme, as well as triangular fragment between coxae III–IV proceeds posteriorly as a band fused with the peritrematic plate. Setal lengths: st 1 16 (13–17), st 2 18 (18–23), st 3 19 (18–20), st 4 15 (13–18), st 5 15 (13–16); Jv 1 14 (10–15), Jv 2 14 (10–15), Jv 3 14 (10–15), Jv 4 17 (13–20), Jv 5 18 (15–20), Zv 2 11 (10–15), Zv 3 11 (10–13); para-anal 10 (8–13), post-anal 8 (5–10). Ventral setae aciculate to spine-shaped, and smooth.

Peritrematic plate and peritreme. Peritrematic plate fused with dorsal shield anteriorly next to level of z 2– z 3 ( Fig. 6 ); extending posteriorly beside coxa IV, to fuse with posteriormost fragment of exopodal plate, truncate at posterior end ( Figs 9 and 11 ); with a narrow somewhat darkened strip along the outer margin of the peritreme ( Fig. 12 ), sectioned at different points by 3–7 transverse to oblique lines; this is sided by a smooth strip running from posterior end to level between coxae II–III, where it widens up; that strip is in turn sided by an external tuberculate strip that widens up distally anteriad level between coxae II–III; the fused section behind the stigma has two distinguishable lyrifissures (ip 3 and ip 4, sensu Lindquist & Moraza, 2008) and one pore (gp 2, sensu Lindquist & Moraza, 2008); lyrifissure ip 2 and pore gp 1, between coxae II–III, inconspicuous. Peritreme about as wide as stigma, extending forward almost to level of j 1; only anterior tip visible from a dorsal view.

Spermathecal structure. ( Fig. 13 ). Of the phytoseiid-type, consisting of a discrete trumpet-like structure whose narrow end has a short, swollen section, which narrows down forming a short duct; minor duct indistinguishable.

Legs ( Figs 14–17 ). Lengths: I: 224 (215–238); II: 216 (205–233); III: 207 (198–218); IV: 258 (248–273). Chaetotaxy: coxa: I—0, 0/1, 0/1, 0; II—0, 0/1, 0/1, 0; III—0, 0/1, 0/1, 0; IV—0, 0/1, 0/0, 0; trochanter: I—1, 0/1, 1/2, 1; II—1, 0/1, 0/2, 1; III—1, 1/1, 0/2, 0; IV—1, 0/1, 0/2, 0; femur: I—2, 3/2, 2/1, 2; II—2, 3/1, 2/2, 1; III—1, 2/1, 1/0, 1; IV—1, 2/1, 1/0, 1; genu: I—2, 3/2, 3/1, 2; II—2, 3/1, 2/1, 2; III—2, 2/1, 2/1, 1; IV—2, 2/1, 3/0, 1; tibia: I—2, 3/2, 3/1, 2; II—2, 2/1, 2/1, 2; III—2, 1/1, 2/1, 1; IV—2, 1/1, 3/1, 2; tarsus: I—not counted; II—18; III—18; IV—18.

Tarsus I with an elongate 30 (28–32) and curved seta s (“isthmochète” = “ s ” seta, of Athias-Henriot, 1972). Basifemur of leg I of distinctly smaller diameter than telofemur (respectively about 20 and 28 in diameter). Most dorsal and lateral setae of trochanter to tibia of all legs set on distinct tubercles. Setae ad 2 and pd 2 of tarsus II relatively stout and elongate, reaching tip of tarsus; setae ad 2 and pd 2 of tarsus III also relatively stout and elongate, reaching respectively bases of a1 1 and pl 1. Pretarsi of all legs consisting of a pair of claws and a pulvillus with broad and rounded central lobe; pretarsus of leg I much smaller than others.

Adult male. Unknown.

Immature stages. Unknown.

Type specimens. All specimens collected from soil/litter samples taken from Sao Paulo State, Brazil, between 30 and 850 m above sea level. Holotype female and nine paratype females collected at Escola Superior de Agricultura “ Luiz de Queiroz ” ( ESALQ), Universidade de S ã o Paulo ( USP), Piracicaba, by A.C. Pereira on November 11, 2000. One paratype female collected at S ã o Pedro by A.R. Oliveira on February 16, 2000. Holotype and paratypes deposited in the mite reference collection of Departamento de Entomologia e Acarologia, Escola Superior de Agricultura “Luiz de Queiroz”, Universidade de S ã o Paulo, Piracicaba, S ã o Paulo State, Brazil. In addition to the type specimens, 82 other females identified as the same species were collected as follows: at Piracicaba by A.R. Oliveira (21 on November 11, 2000); at São Pedro by A.R. Oliveira (one on May 6, 2000 and seven on August 10, 2000); at Pariquera-açu by A.R. Oliveira (two on January 8, 2000); and at São Carlos by V. Borges (29 on December 3, 2021; four on October 29, 2021; seven on January 28, 2022; and eight on April 29, 2022).

Etymology. The specific name luizdequeirozi refers to Luiz Vicente de Souza Queiroz, donor of the property where Escola Superior de Agricultura Luiz de Queiroz (ESALQ), a renowned campus of the University of S ã o Paulo (USP), was established over 120 years ago, and where the holotype and some paratypes were collected.

Diagnostic similarities and differences with Zercoseius spathuliger . The following comparison refers only to adult females. The similarities between the two species presently placed in this genus include the presence of a single, strongly sclerotised dorsal shield covering completely the dorsum of the idiosoma; the absence of setae z 1, s 2 and Zv 1; similar lengths of fixed and movable cheliceral digits, the first with five teeth and a setiform pilus dentilis, and the second with two teeth; epistome with three anterior projections; deutosternum relatively wide; 2-tined palptarsal claw; posterior margin of sternal shield concave; seta st 4 and lyrifissure iv 3 inserted in the metasternal plates; broad epigynal and ventrianal shields, the first encompassing seta st 5 and lyrifissure iv 5, and the second with all the opisthogastric setae present in these species (Jv 1– Jv 5, Zv 2, Zv 3 and circumanals); anal opening relatively small; gv 3 indistinguishable; metapodal plates not discrete; anterior section of endopodal strip fused with sternal shield; peritrematic plate broad, fused with the exopodal plate next to coxa IV, and the fused section posteriorly truncate; basifemur of leg I of much smaller diameter than telofemur; tarsus I with an elongate and curved seta s.

However, Z. spathuliger differs from the new species in relation to the following aspects: delimiting lateral lines of the deutosternum not jagged; dorsal and ventral shields with different ornamentation; seta s 1 absent; most dorsal shield setae of different shapes; seta r 3 of different orientation (perpendicular to shield margin) and shape in comparison with neighbouring setae; no large crater-like structures next to lyrifissures iv 1 and iv 2; tibia II with one pl setae, and genu and tibia III with two pl; setae ad 2 and pd 2 of tarsi II and III not stout and elongate (characteristics of leg setae provided by E.E. Lindquist, in personal communication). Additionally, the insertion of R 1 is shown on the dorsal shield by Westerboer (1963), but on the unsclerotised cuticle by Evans (1958). The endopodal plate between legs III–IV is shown as slim strip by Evans (1958) and it is not shown by Westerboer (1963); an examination of the photographs of the specimens in the Berlese Acarotheca indicates this plate to be either absent or very small.

Figures

FIGURES 1–5. Zercoseius luizdequeirozi n. sp., adult female. 1. Lateral (antiaxial) view of chelicera; 2. Hypostome; 3. Palptarsal claw; 4. Epistome; 5. Epistome (DIC micrograph).

FIGURES 6–8. Zercoseius luizdequeirozi n. sp., adult female. 6. Dorsal view of idiosoma; 7. Ornamentation of part of dorsal shield (DIC micrograph); 8. Setae J2–J4 (DIC micrograph).

FIGURES 9–13. Zercoseius luizdequeirozi n. sp., adult female. 9.Ventral view of idiosoma; 10. Sternal shield (DIC micrograph); 11. Fusion of peritrematic and exopodal plate near coxa IV (DIC micrograph); 12. Section of peritreme (DIC micrograph); 13. Sperm access system (variants).

FIGURES 14–17. Zercoseius luizdequeirozi n. sp., adult female. 14. Leg I: a, coxa-tibia; b, tip of tarsus with seta s; 15. Leg II: a, coxa-tibia; b, tarsus; 16. Leg III: a, coxa-tibia; b, tarsus; 17. Leg IV: a, coxa-tibia; b, tarsus.