Blattisocius thaicocofloris, Oliveira, Daniel C., Chandrapatya, Angsumarn & De Moraes, Gilberto J., 2015

Oliveira, Daniel C., Chandrapatya, Angsumarn & De Moraes, Gilberto J., 2015, A new species of Blattisocius (Acari: Mesostigmata: Blattisociidae), with a new characterisation of the genus, Zootaxa 4040 (1), pp. 93-100 : 94-98

Blattisocius thaicocofloris n. sp.

( Figs 1–20 )

Diagnosis. Females and males: corniculi parallel to each other; para-anal setae inserted about in line with posterior margin of anal opening. Females: corniculi not well separated; dorsal shield with lateral incisions between s6 and S1; podonotal and opisthonotal regions of dorsal shield with 21 and 15 pairs of setae, respectively; 11 pairs of setae on unsclerotised cuticle surrounding the dorsal shield, two on podonotal region and nine on opisthonotal region; iv3 indistinguishable; ventrianal shield with four pairs of setae in addition to circumanals. Males: without lateral incisions on dorsal shield; podonotal and opisthonotal regions of dorsal shield with 23 and 21 pairs of setae, respectively; three pairs of setae on opisthonotal region of the unsclerotised cuticle surrounding the dorsal shield; ventrianal shield with five pairs of setae in addition to circumanals; with ventral spur-shaped setae on leg II.

Type specimens. Holotype female collected on 23 March 2013 from flowers of Cocos nucifera L. at Kamphaeng Saen District (14o 00' 22'' N, 99o 59' 78'' E), Nakhon Pathom Province, Thailand, by D.C. Oliveira and S. Buttachon, deposited at the mite reference collection of Departamento de Entomologia e Acarologia, Escola Superior de Agricultura "Luiz de Queiroz" ( ESALQ), University of Sao Paulo ( USP), at Piracicaba, Sao Paulo State, Brazil). Four paratype females collected on 27 December 2012 and one paratype male and one paratype female collected on 28 January 2013, other data same as holotype, deposited at ESALQ-USP. One paratype female collected on 23 August 2012, one paratype female collected on 20 November 2012 and two paratype females collected on 28 January 2013, other data same as holotype, deposited at the Museum of the Kasetsart University, Chatuchak, Bangkok, Thailand.

Description. Female (n= 10). Figures 1–14 .

Dorsal idiosoma ( Fig. 1 ). Dorsal shield 461 (440–477) long and 252 (232–265) wide at level of setae r3; mostly reticulate and punctate, with lateral incisions between s6 and S1; very lightly sclerotised. Podonotal region of dorsal shield with 21 pairs of setae, five pairs of lyrifissures and four pairs of pores. Opisthonotal region of dorsal shield with 15 pairs of setae, 11 pairs of lyrifissures and three pairs of pores. Measurements of dorsal shield setae: j1 28 (26–30), j2 19 (17–21), j3 19 (17–21), j4 19 (17–20), j5 19 (17–20), j6 19 (17–21), J1 20 (17–22), J2 22 (20–24), J3 23 (22–24), J4 26 (23–28), J5 12 (12–13), z1 17 (16–19), z2 20 (17–23), z3 20 (18–22), z4 21 (19– 22), z5 19 (18–20), z6 21 (19–23), Z1 23 (22–25), Z2 24 (22–26), Z3 25 (23–26), Z4 30 (27–32), Z5 49 (45–52), s1 18 (17–18), s2 18 (17–19), s3 22 (20–23), s4 22 (20–23), s5 23 (21–25), s6 24 (22–26), S1 25 (23–26), S2 29 (27– 30), S3 33 (30–34), S4 40 (35–43), S5 37 (33–40), r2 24 (22–25), r3 24 (22–26), extra seta (x) 24 (23–25) (inserted posteromesad of r3, paired in one paratype, present only on left side of holotype and two paratypes, absent in other six paratypes), r4 24 (22–26). Lateral unsclerotised cuticle with eight pairs of marginal and three pairs of submarginal setae. Measurements of setae on unsclerotised cuticle as follows: r5 25 (22–26), r6 26 (25–27), R1 27 (25–27), R2 28 (26–30) (absent on right side of one paratype), R3 27 (25–29), R4 28 (26–31) (absent the left side of one paratype), R5 29 (26–30) (absent on left side of one paratype), R6 31 (29–34), UR2 24 (23–25), UR4 26 (23– 28), UR5 27 (25–29) (absent on left side of one paratype and on right side of another paratype). All setae of similar length and shape, slender and smooth, except Z5 longer, relatively stout and sparsely serrate ( Fig. 2 ).

Ventral idiosoma ( Fig. 3 ). All shields very lightly sclerotised. Sternal shield punctate, with sparse lines parallel to lateral margins; with three pairs of setae and two pairs of lyrifissures; setal lengths: St1 30 (28–31), St2 24 (18– 26) and St3 27 (23–30); distances between St1–St3 96 (91–102) and St2–St2 80 (76–85). Metasternal plates absent; seta St4 18 (15–21) on unsclerotised cuticle, third pair of ventral lyrifissures (iv3) absent. Epigynal shield punctate, lateral margins moderately concave, truncated posteriorly and bearing genital seta St5 19 (15–21); distance between St5–St5 61 (56–63); paragenital lyrifissure on unsclerotised cuticle posterolaterad of genital seta. Ventrianal shield 137 (132–145) long, 164 (150–177) wide at level of ZV2 and 91 (85–95) at anus level; totally punctate, narrowing behind JV3; lineate anteriad of anus; with four pairs of opisthogastric setae in addition to circumanal setae: JV1 17 (15–19), JV2 18 (15–20), JV3 20 (19–23) and ZV2 20 (18–22); pores and lyrifissures indistinguishable; postanal seta 26 (23–29); para-anal setae 25 (21–26), inserted in line with the posterior margin of anus. Six pairs of opisthogastric setae on unsclerotised cuticle around ventrianal shield: JV4 26 (25–28) (absent on right side of holotype and on left side of one paratype), JV5 39 (36–42), ZV1 18 (14–21), ZV3 21 (20–21), ZV4 31 (27–33) (absent on right side of one paratype) and ZV5 34 (31–36). All setae slender and smooth. One pair of ellipsoid metapodal plates. Anterior section of endopodal plate fused with sternal shield, and absent posteriorly. Exopodal plate represented by an inverted comma-shaped platelet near posterior margin of coxa II, a more elongate platelet running from anterior margin of coxa III to region between coxae III–IV (narrowed to a thin line near middle of coxa III), and a curved section near margin of coxa IV fused with peritrematic plate; the latter narrow, with a pore and two lyrifissures on each side behind stigma, connecting to dorsal shield anteriad of s1. Peritreme extending anteriorly to level of z1.

Spermatheca ( Figs 4–6 ). Major duct leading to a strongly sclerotised cylindrical calyx, 11 (8–14) long and 5 (4–5) in diameter; minor duct long, rather thin and sometimes difficult to see.

Gnathosoma . Cheliceral shaft, excluding basal article, 121 (115–125) long; fixed cheliceral digit 47 (44–50) long, with slender pilus dentilis (about 20 long, very lightly sclerotised, and difficult to see), and three teeth (one large basal tooth and two subapical teeth, in addition to apical hook) ( Fig. 7 ); movable cheliceral digit 57 (54–61) long, with three teeth in addition to apical hook. Gnathotectum with anterior margin inverse-V-shaped, smooth with vertex rounded ( Figs 8–9 ). Deutosternum with seven connected transverse denticulate rows; most distal with three denticles; second to fifth rows each with 6–8 denticles; sixth with 8–12 denticles and seventh with 15–20 denticles ( Fig. 10 ). Corniculi parallel to each other, not widely spaced. Palpus length 124 (120–125), with normal chaetotaxy for the Gamasina as described by Evans (1963b); numbers of setae from trochanter to tarsus: 2, 5, 6, 14, 15; apotele two-tined; inner palp-trochanter seta slightly [20 (19-20)] shorter than outer palp-trochanter seta [23 (22-23)]. Subcapitular setae slender, h1 24 (20–26), h2 18 (16–19), h3 33 (30–35) and sc 28 (26–30).

Legs ( Figs 11–14 ). Legs I–IV with paired claws and with central lobe of pulvilli rounded, inserted on well developed pretarsi. Leg lengths (from base of coxa to apex of tarsus): I: 334 (320–350); II: 283 (275–295); III 272 (262–295); IV: 341 (332–360). All setae slender and smooth; setation of legs I–IV: coxa: 2, 2, 2, 1; trochanter: 1 0/ 1 1/2 1; 1 0/1 0/2 1; 1 1/1 0/1 1; 1 1/1 0/1 1; femur: 2 3/1 2/1 2; 2 3/1 2/2 1; 1 2/1 1/0 1; 1 2/1 1/0 1; genu: 2 3/2 3/1 2; 2 3/1 2/1 2; 2 2/1 2/1 1; 2 2/1 3/0 2; tibia: 2 3/1 3/2 2; 2 2/1 2/1 2; 2 1/1 2/1 1; 2 1/1 3/1 2; tarsus: 38, 18, 18, 18.

Male (n=1). Figures 15–20 .

Dorsal idiosoma ( Fig. 15 ). Dorsal shield 350 long and 225 wide at level of setae r3; mostly reticulate and punctate; very lightly sclerotised. Podonotal region of dorsal shield with 23 pairs of setae, five pairs of lyrifissures and four pairs of pores. Opisthonotal region of dorsal shield with 21 pairs of setae, 11 pairs of lyrifissures and three pairs of pores. Measurements of dorsal shield setae: j1 23, j2 18, j3 18, j4 16, j5 16, j6 17, J1 19, J2 17, J3 24, J4 30, J5 10, z1 17, z2 18, z3 17, z4 19, z5 18, z6 20 (absent on left side), Z1 23, Z2 23, Z3 28, Z4 38, Z5 60, s1 16, s2 17, s3 21, s4 21, s5 21, s6 24, S1 25, S2 32, S3 42, S4 61, S5 57, r2 23, r3 26, r4 25, r5 27, r6 27, extra seta (x) 27 (inserted between bases of r6 and R1 on left side), R1 28, R2 32, R3 30, R4 27, R5 31, R6 37. Lateral soft cuticle with three pairs of submarginal setae: UR2 24, UR4 24 and UR5 30. Podonotal setae of similar length and shape; opisthonotal setae progressively longer towards posterior end, except J5; dorsal idiosomal setae slender and smooth, except Z4, Z5, S3, S4 and S5, stouter and smooth, except Z5, sparsely serrate.

Ventral idiosoma ( Fig. 16 ). All setae slender. All ventral plates very lightly sclerotised. Sternogenital shield punctate and with sparse striae parallel to lateral margins, with five pairs of setae and three pairs of lyrifissures; setal lengths: St1 18, St2 14, St3 13, St4 13, St5 18; distances between St1–St5 138, St2–St2 63 and St5–St5 35. Ventrianal shield punctate and lineate, 128 long, 180 wide at level of JV1 and 100 wide at anus level, covering most of opisthogaster, not fused to peritrematic and sternogenital shields; with five pairs of opisthogastric setae: JV1 20, JV2 20, JV3 22, ZV1 17 (absent on right side) and ZV2 22, in addition to circumanal setae and one pair of lyrifissures; postanal seta 31; para-anal setae 23, inserted in line with posterior margin of anus. Three pairs of opisthogastric setae on unsclerotised cuticle around ventrianal shield: JV5 48, ZV4 36 and ZV5 40. Exopodal plate similar to adult female. Anterior end of peritrematic plate fused to dorsal shield at region between s1 and s3; posterior end with a pair of lyrifissures and a pore on each side immediately behind stigma; fused to posterior remnant of exopodal shield, which curves behind coxa IV; peritreme as in adult female.

Gnathosoma . Cheliceral shaft, excluding basal segment, 85 long; fixed cheliceral digit 30 long, pilus dentilis not seen, with six teeth in addition to apical hook ( Fig. 17 ); movable cheliceral digit 28 long, with single proximal tooth in addition to apical hook. Spermadactyl L-shaped; shaft 21 long; toe 18 long, with an apical lobe. Gnathotectum similar to female ( Fig. 18 ). Deutosternal denticles apparently in six connected rows, anterior most with three relatively large denticles, others with multiple tiny teeth ( Fig. 19 ). Palpus length 95, with chaetotaxy and numbers of seta from trochanter to tarsus as in female; apotele two-tined; inner palp-trochanter seta (16) slightly shorter than outer palp-trochanter seta (18). Subcapitular setae slender: h1 22, h2 19, h3 26 and sc 22.

Legs. Legs I–IV with paired claws and central lobe of pulvilli rounded, inserted on well developed pretarsi. Leg lengths (from base of coxa to tip of tarsus): I: 260; II: 230; III: 225; IV: 287. Chaetotaxy, number and shape of setae as in adult female, except for some ventral setae of leg II (pv1 of femur, av of genu, av and pv of tibia and mv of tarsus) which are enlarged (spur-shaped) ( Fig. 20 ).

Etymology. The name thaicocofloris refers to a combination of thai (for Thailand, country where the type specimens were collected), coco (for coconut, the host plant) and floris (Latin for flower, plant part onto which the types were collected).

Remarks. Some outstanding characteristics of the new species are the very light sclerotisation of the shields, as well as the frequent absence of various setae and the occasional presence of extra setae in both females and males. This species resembles Adhaerenseius floralis Loots & Theron, 1992 , the single species in Adhaerenseius , by having female dorsal shield with midlateral incisions, corniculi parallel to each other, trochanter – tarsus of male leg II with enlarged spur-shaped setae (spur-shaped setae also present on trochanter I, femur I, tarsus II, and femurtibia IV in Adhaerenseius ). However, it differs especially in having opisthonotal region of dorsal shield with 15 pairs of setae, female metasternal plate and metasternal lyrifissure (iv3) absent, genu III with 10 and genu IV with 11 setae. A major distinctive autapomorphy of larvae and nymphs of Adhaerenseius refers to the presence of opisthogastric sucker-like structures, but immatures of the new species are unknown.

The new species is similar to some other species of Blattisocius , which however do not have midlateral incisions on dorsal shield, and which have corniculi very close together and distally convergent, metasternal lyrifissure (iv3) present, 12 setae on femur I, nine setae on genu IV (setal deficiencies occur in several leg segments of Blattisocius apisassociae Chinniah & Mohanasundaram ), and male with no leg setae enlarged and spur-shaped.

Figures

FIGURES 1 – 14. Blattisocius thaicocofloris n. sp. Female. 1. Dorsal shield; 2. Enlarged view of seta Z 5; 3. Ventral idiosoma; 4 – 6. Different views of spermatheca; 7. Chelicera; 8 – 9. Different views of gnathotectum; 10. Ventral gnathosoma; 11. Leg I; 12. Leg II; 13. Leg III; 14. Leg IV.

FIGURES 15 – 20. Blattisocius thaicocofloris n. sp. Male. 15. Dorsal shield; 16. Ventral idiosoma; 17. Chelicera and spermadactyl; 18. Gnathotectum; 19. Ventral gnathosoma; 20. Leg II.