Leioseius cananeiensis, Santos, Jandir C. & De Moraes, Gilberto J., 2016

Santos, Jandir C. & De Moraes, Gilberto J., 2016, A new species of Leioseius (Acari: Ascidae) from Brazil, redescription of Leioseius basis and a key for separation of the world species of the genus, Zootaxa 4158 (1) : -

Leioseius cananeiensis n. sp.

Diagnosis (female): podonotal region of dorsal shield with 20 pairs of setae (j 1– j 6, z 1– z 6, s 1– s 6, r 2 and r 4; some specimens with s 2 off the shield on one or both sides, r 4 off the shield on one side or a pair of extra setae between z 3 and z 4); opisthonotal region with 16 pairs of setae (J 1– J 5, Z 1– Z 5, S 1– S 5 and R 1; some specimens with R 1 off the shield on one or both sides). Unsclerotised cuticle along lateral margins of dorsal shield usually with two pairs of setae (r 3 and r 5; some specimens with r 2, r 4 or R 1 on the cuticle in one or both sides); pre-sternal area lightly sclerotised; ventrianal shield subtrapezoidal, with a pair of short anterolateral lobes, with six pairs of setae (Jv 2– Jv 5, Zv 2, Zv 3; some specimens with Zv 2 on one side or Zv 3 on both sides inserted on unsclerotised cuticle) in addition to circumanal setae; para-anal and post-anal setae similar in length, the former inserted slightly anteriad of level of posterior margin of anal opening; all legs with pretarsi and claws; median section of pulvilli rounded and paradactyli acuminate. Setae pl 1 and pl 2 of tibia IV and pl 3 of tarsus IV distinctly stouter than other setae of same respective segment; Setae pd 1 and pd 2 of femur I lightly pilose. Legs without macrosetae.

Type material. Holotype female and nine paratype females collected from roots of L. racemosa partially covered with barnacles from mangrove plants along the edge of Mar Pequeno canal (brackish water) at Cananéia (24°57’25''S and 47°54’28"W), São Paulo State, Brazil ; collected by G.J. Moraes on January 22, 2015 and January 12, 2016; deposited in the mite reference collection of Departamento de Entomologia e Acarologia, Escola Superior de Agricultura “ Luiz de Queiroz ”, Universidade de São Paulo, Piracicaba, São Paulo State, Brazil .

Adult female ( Figs 1–14 ) (Ten specimens measured).

Gnathosoma. Antiaxial and dorsal lyrifissures as well as dorsal seta distinct ( Fig. 1 ); fixed cheliceral digit 53 (52–55) long, with six teeth in addition to apical tooth (five in a paraxial line and one in an antiaxial line) and a minute setiform pilus dentilis; movable cheliceral digit 52 (51–54) long, with two teeth in addition to apical tooth. Palp setae (trochanter to tibia): 2-5-6-13; all setae aciculate and smooth. Anterior region of epistome with three short extensions, each 5–6-tined ( Fig. 2 ). Deutosternum delimited by lateral lines, with anteriormost transverse line smooth followed by six transverse lines of denticles, about parallel to each other, the first four lines with 5–7 denticles and the last two with 10–13 smaller denticles; corniculus horn-shaped, about 32 (31–33) long (from median level of base to tip) and 28 (28–29) wide basally; seta h 2 about transversely aligned with h 3 ( Fig. 3 ). Measurements of setae: h 1 42 (40–45), h 2 23 (22–25), h 3 46 (43–45), pc 30 (30–31).

Dorsal idiosoma ( Fig. 4 ). Dorsal shield smooth, 554 (550–555) long and 299 (296–300) wide at widest level. Podonotal and opisthonotal shields fused, with distinct lateral incisions at region of fusion. Podonotal region with 20 pairs of setae (j 1– j 6, z 1– z 6, s 1– s 6, r 2 and r 4; s 2 off the shield on one or both sides in respectively four and one specimens; r 4 off the shield on one side in one specimen; with a pair of extra setae, x, between z 3 and z 4, in one specimen), five pairs of distinguishable lyrifissures and three 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; the latter off the shield on one or both sides in respectively three and one specimens), 11 pairs of distinguishable lyrifissures and three pairs of distinguishable pores. Unsclerotised cuticle along lateral margins usually with two pairs of setae (r 3 and r 5; in some specimens r 2, r 4 and R 1 can be on the cuticle in one or both sides of the shield). Setal measurements: j 1 31 (30–32), j 2 33 (32–34), j 3 34 (33–35), j 4 32 (31–32), j 5 31 (31–32), j 6 32 (31–32), J 1 32 (30–33), J 2 31 (32–31), J 3 26 (25–28), J 4 26 (25–26), J 5 28 (27–30), z 1 36 (35–37), z 2 34 (32–35), z 3 36 (31–40), z 4 35 (35–36), z 5 31 (30–32), z 6 30 (30–31), Z 1 34 (32–36), Z 2 38 (35–40), Z 3 62 (60–65), Z 4 71 (70–73), Z 5 69 (67–70), s 1 32 (31–32) , s 2 30, s 3 40 (39–40), s 4 42 (40–43), s 5 39 (38–40), s 6 34 (33–35), S 1 31 (30–32), S 2 40 (40–41), S 3 39 (37–40), S 4 42 (41–42), S 5 57 (51–67), r 2 36 (33–38), r 3 33 (31–35), r 4 30 (30–31), r 5 32 (31–40), R 1 30 (27–32), x 35 –36. All setae aciculate and smooth, except J 5 and Z 5, lightly pilose ( Fig. 5 ).

Ventral idiosoma ( Fig. 6 ). Base of tritosternum 20 (20–21) long and 17 (15–17) wide proximally ( Fig. 7 ); laciniae 95 (95–95) long, separated for about 75% of their total length, pilose along about 85% of the divided section. Pre-sternal area lightly sclerotised, barely distinguishable in most specimens. Sternal shield 84 (82–87) long at mid-line and 106 (100–110) wide between setae st 1 and st 2, smooth; posterior margin concave; with two pairs of setae (st 2 and st 3) and three pairs of lyrifissures (iv 1– iv 3); st 1 inserted on lightly sclerotised presternal area; with prominent endopodal projections between coxae I and II; with small variations in the anterior and posterior margins ( Fig. 8 ). Seta st 4 inserted on unsclerotised cuticle. Genital shield smooth, apex of hyaline anterior region rounded, posterior margin truncate; widened posteriorly to include st 5 and iv 5, distance st 5- st 5 82 (81–84). One pair of elliptical metapodal plates. Ventrianal shield subtrapezoidal, with a pair of short anterolateral lobes, 161 (153–175) long at mid-line and 212 (205–220) wide at widest level; with six pairs of setae (Jv 2– Jv 5, Zv 2, Zv 3 one specimen without Zv 2 on one side; another specimen with both Zv 3 inserted on unsclerotised cuticle) in addition to circumanal setae; para-anal and post-anal setae similar in length, the former inserted slightly anteriad of level of posterior margin of anal opening. With four elongate and transversely aligned platelets between genital and ventrianal shields. Usually with four pairs of opisthogastric setae on unsclerotised cuticle flanking ventrianal shield (Jv 1, Zv 1, Zv 4 and Zv 5). Anterior section of endopodal plate fused with sternal shield; posterior section slender and elongate, usually meeting distal extension of peritrematic-exopodal shield that encircles posterior margin of coxa IV (line of fusion indistinguishable or barely distinguishable near median level of coxa IV). Exopodal plate distinguishable as two discrete, subtriangular platelets between coxae II-III and III-IV. Measurements of setae: st 1 36 (35–37), st 2 35 (33–35), st 3 34 (33–35), st 4 35 (35–36), st 5 35 (35–36); Jv 1 32 (31– 34), Jv 2 35 (35–36), Jv 3 38 (35–40), Jv 4 38 (36–40), Jv 5 53 (50–58), Zv 1 26 (25–26), Zv 2 31 (30–34), Zv 3 26 (25– 27), Zv 4 27 (26–27), Zv 5 31 (30–31); para-anal 46 (48–52), post-anal 51 (50–55). All setae aciculate and smooth.

Peritreme and peritrematic plates. Peritreme about as wide as stigma, extending forward almost to level of z 1; anterior half visible from a dorsal view. Peritrematic plate fused with dorsal shield anteriad of s 1, extending posteriorly behind coxa IV; with one pair of distinguishable lyrifissures and one pair of pores next to coxae II and with two pairs of distinguishable lyrifissures behind stigma, probably fused with posterior end of exopodal shield beside and posteriad of coxa IV.

Spermathecal apparatus. ( Fig. 9 ) Insemination pore located at inner posterior margin at base of coxa IV; infundibulum distinct, followed by the uniformly narrow tubulus that connects to sacculus away from tubulus of opposite side; sperm duct annulated, leading to a spherical receptaculum.

Legs. ( Figs 10–14 ) Lengths: I: 498 (498–500); II: 416 (413–420); III: 404 (400–410); IV: 494 (490–495). Chaetotaxy (legs I–IV): coxae—0 0/1 0/1 0; 0 0/1 0/1 0; 0 0/1 0/1 0; 0 0/1 0/0 0; trochanters—1 0/1 1/2 1; 1 0/1 0/ 2 1; 1 1/1 0/2 0; 1 1/1 0/2 0; femora –2 3/1 2/2 2; 2 3/1 2/2 1; 1 2/1 1/0 1; 1 2/1 1/0 1; genua—2 3/1 3/1 2; 2 3/1 2/1 2; 2 2/1 2/1 1; 2 2/1 3/0 1; tibiae—2 3/1 3/1 2; 2 2/1 2/1 2; 2 1/1 2/1 1; 2 1/1 3/1 2; tarsi II–IV 18, 18, 18. All legs with pretarsi, including a pair of claws and pulvilli with median section rounded. Legs II–IV with elongate and acuminate paradactyli ( Fig. 14 ). Setae pl 1 and pl 2 of tibia IV and pl3 of tarsus IV distinctly stouter than other setae of same respective segment; femur I with pd 1 and pd 2 lightly pilose; other setae aciculate and smooth. Legs without macrosetae.

Adult male. Unknown.

Etymology. The term “ cananeiensis ” refers to “from Cananéia”, the type locality of this species. Remarks. Leioseius cananeiensis n. sp. is most similar to Leioseius australis Luxton, 1984 , but females of the latter have distinct presternal platelets; incisions between podonotal and opisthonotal regions of dorsal shield reaching only level of s–S series; fixed cheliceral digit with two teeth in addition to apical tooth and genital shield narrower posteriorly, seemingly not including iv 5.

Figures

FIGURES 1 – 9. Leioseius cananeiensis n. sp. Female. 1. Antiaxial view of chelicera; 2. Epistome; 3. Hypostome; 4. Dorsal view of idiosoma; 5. Setae J 5 and Z 5; 6. Ventral view of idiosoma; 7. Tritosternum; 8. Variation in shape of sternal shield; 9. Spermathecal apparatus. Lyrifissures and pores enlarged for improved visibility.

FIGURES 10 – 14. Leioseius cananeiensis n. sp. Female. 10. Leg I; 11. Leg II; 12. Leg III; 13. Leg IV; 14. Pretarsus of legs II.