Lasioseius duobtusisetis, Moraza & Lindquist, 2018

Moraza, Maria L. & Lindquist, Evert E., 2018, A new species-group with new species of the genus Lasioseius (Acari: Mesostigmata: Blattisociidae) associated with Neotropical hispine beetles in furled leaves ofHeliconia, Acarologia 58 (1), pp. 62-98 : 88-93

Lasioseius duobtusisetis n. sp. ( Figures 10 , 12 E-F, 13I, 14C)

Zoobank: F8B79273-9C72-4212-816C-8BC080C933CE

Diagnosis. Adult female: Sternal shield weakly lineate along lateral margins, smooth medially, its posterolateral corners not emarginated; poroids iv3 and setae st4 together on slender metasternal platelets; epigynal shield partially reticulated laterally, its lateral margins gently concave, narrowed anterior to setae st5; ventrianal shield with posterolateral margins on either side of anus nearly parallel, and with four pairs of opisthogastric setae, JV1 on shield; metapodal plates well separated on each side. Dorsal setae r6 on soft cuticle; setae Z5, S5 thickened, spinelike with blunt tips, Z4, S4 somewhat thickened but attenuated. Adult attributes: Gnathotectum anterior margin triramous, denticulate. Fixed chela with file of ca 20 teeth in female. Sternal setae st1 inserted on anterior edge of sternal shield. Tarsi II-IV with ventral apical process bluntly pointed, smooth apically; tarsi II-III with setae (v-1), (l-1) symmetrically stout; tarsus IV with apical seta av-1 longer, stouter than pv-1, (l-1), and pretarsus with anterior paradactylus longer than posterior one.

Description

Idiosomatic dorsum — Adult female. Dorsal shield 540 – 595 long, 293 – 319 wide at level of r3, 320 – 345 at level of r5 (n=4), lightly reticulated over most of surface, but nearly smooth in dorsal hexagonal area (delimited by setae j5-z5-j6), not punctate behind level of setae Z4, but finely transversely striate between Z5 behind J5; shield with 37 pairs of setae, with lengths of most podonotal setae and J1-J3 not reaching bases of following setae; Z5, S5 thickened, spinelike with blunt tips, Z4, S4 somewhat thickened but attenuated ( Figs. 10A, B ): j1 (34 – 42), j2 (31 – 40), j3 (39 – 43), j4 (28 – 34), j5 (30 – 37), j6 (38 – 50), z1 (24 – 27), z2 (33 – 40), z3 (40 – 43), z4 (40 – 50), z5 (30 – 38), z6 (37 – 40), s1 (29 – 35), s2 (38 – 50), s3 (43 – 50), s4 (40 – 51), s5 (45 – 52), s6 (50 – 57), r2 (40 – 50), r3 erect (38 – 42), r4 (44 – 57), r5 (47 – 57), J1 (33 – 38), J2 (33 – 42), J3 (43 – 52), J4 (40 – 57), J5 minute and barbed (7 – 9), Z1 (53 – 62), Z2 (58 – 62), Z3 (62 – 70), Z4 (80 – 87), Z5 blunt (85 – 103), S1 (48 – 59), S2 (55 – 67), S3 (58 – 69), S4 (63 – 75), S5 blunt (75 – 90). Lateral soft cuticle with eight pairs of smooth setae, including r6 (45 – 60), R1 (35 – 52), R2-R6 shorter (28 – 42) and ZV5 posteriorly (40) ( Fig. 10C ).

Idiosomatic venter — Adult female. Tritosternum base 26 – 35 long, 15 – 16 wide at its base, with paired laciniae fused for about 10 – 17 of their total length (112 – 118). Presternal region with circumscribed pair of weakly granulated areas with jigsawed lineation, sometimes flanked anteriorly by a pair of narrow slightly sclerotized strips. Sternal shield 115 – 127 long, with slightly concave posterior margin, 98 – 109 wide, its surface nearly smooth medially, weakly lineate along lateral margins; sternal setae st1-st3 attenuate, of similar length (21 – 25) ( Fig. 10C ). Sternal poroids iv3 and setae st4 (20 – 22) inserted together on small metasternal platelets (21 – 26 long). Endopodal strips narrow between coxae III and IV. Epigynal shield with lightly reticulated lateral areas separated by smooth area medially, its narrowly rounded hyaline anterior margin reaching or slightly overlapping posterior edge of sternal shield, its lateral margins slightly concave, narrowed anterior to setae st5 (20 – 24), and its posterolateral corners slightly emarginated behind st5: shield 178 – 197 long, 82 – 102 at widest level at posterior angulate corners, 70 – 75 at level of st5, and 54 – 62 at narrowest width between legs IV. Opisthosomatic venter with two pairs of well separated metapodal platelets, primary pair oval, 30 – 40 long, 15 – 19 wide, secondary pair small, greatest dimension transverse, 18 – 25. Ventrianal shield inversely subtriangular with rounded anterior corners, with posterolateral margins on either side of anus nearly parallel; surface entirely sculptured, with primarily transverse lineation changing to reticulation behind setae JV2-ZV2, except anal region conspicuously punctate on either side of postanal seta; shield wider (216 – 235) than long, including cribrum (176 – 197), 113 – 132 wide at anal region; shield with four pairs of ventral setae and glandular pores gv3: JV1 (19 – 22), JV2 (22 – 25), JV3 (23 – 27), ZV2 (23 – 29); with paranal setae (17 – 20) shorter than postanal seta (36 – 45). Soft cuticle with five pairs of simple opisthogastric setae, ZV1 (22 – 24) anterior to ventrianal shield, ZV3 (22 – 26), ZV4 (25 – 33), JV5 markedly thicker (53 – 57) flanking the shield, and ZV5 somewhat aligned behind R6; four pairs of poroids (including ivp). Peritrematal-exopodal shield lineate posteriorly behind leg IV; peritreme extending to level between insertions of setae s1 and z1 ( Fig. 10C ). Spermathecal apparatus with cup-like calyx 40 long including embolus and 22 wide at distal margin ( Fig. 10 F ).

Gnathosoma — Gnathotectum anterior margin triramous, with three short denticulate prongs, lateral margin slightly serrate ( Fig. 10D ). Cheliceral shaft, excluding basal section, 161 – 182 long, with slender digits; dorsal seta blunt (10); fixed digit with tiny, slightly offset subapical tooth and row of 20-28 very fine teeth ( Fig. 10G ), pilus dentilus minute (3) at level of 4 th or 5 th apical tooth; movable digit (70 – 80) tridentate. Subcapitulum rows of deutosternal denticles each with numerous (ca 20-30) fine denticles, 6 th and sometimes 7 th slightly widest and with ca 35 and 30 teeth, respectively; subcapitular setae hp1 (41 – 45) nearly as long as capitular setae pc (48 – 50), hp3 shorter (30 – 32), but longer than hp2 (13 – 17) ( Fig. 10E ). Palp length (160 – 165); apical margin of palptrochanter with a single spine anterolaterally; palptrochanter setae dissimilar in length, v1 42 – 45 and v2 27 – 36 ( Fig. 10E ).

Legs — Legs I (503 – 562) slightly longer than legs IV (488 – 546), and shorter than dorsal shield; other leg lengths (excluding pretarsi): II 390 – 445, III 380 – 442. Leg I pretarsus with biarticulated shaft (25 – 27 to base of claws), claws 15 long; tarsus (142 – 167) about 1.8 longer than tibia; other length ratios, femur (88 – 105): genu (73 – 82): tibia (80 – 95), about 1.1: 0.9: 1.0. Legs II-III with tarsus/tibia length ratio about 1.8-2.2, leg IV with that ratio about 1.8-1.9. Chaetotactic formulae of leg segments as given for species-group. Tarsi II-IV with ventroapical process (8 – 10) bluntly pointed, smooth apically ( Figs 13I , 14C ), and with setae (d-1) (13 – 18) nearly as long as pretarsus to base of claws (15 – 18). Tarsi II-III with paradactyli reaching tips of tarsal claws, but tarsus IV with anterior paradactylus about 1.5 longer ( Fig. 14C ). Tarsi II and III with setae (l-1) and (v-1) symmetrically stout, pl-1 (18) and pv-1 (18 – 25) slightly longer than al-1 (15) and av-1 (17 – 20), respectively; md (43 – 50) reaching bases of claws; setae (d-2) symmetrically attenuate (45 – 53). Tarsus IV with apical seta av-1 longer (28 – 45), stouter than pv-1 (16 – 23); setae (l-1) symmetrically similar in length (13 – 15), md (55 – 61) and (d-2) (60 – 72) attenuate ( Fig. 14C ).

ADULT MALE. Unknown.

Type material — All specimens collected at the La Selva Biological Station, Heredia Province, Costa Rica (10°26´N, 84°01´W, elevation 50-150 m): HOLOTYPE: adult female, (CRI 002, 739028), 8 July 1997, ex adult Chelobasis perplexa Baly , no host plant data, coll. M Paniagua. PARATYPES: 1 adult female, February 1994, associated with adult Chelobasis sp. on leaf of Heliconia pogonantha , coll. E.E. Lindquist & ALAS; 1 adult female, 15 April 1994, ex adult Chrysomelidae , no host plant data, coll. M. Paniagua; 1 adult female, 12 June 1997, ex adult Cephaloleia aequilata Uhmann (misidentification, see below) on leaf of Calathea , coll. ALAS; 1 adult female, 12 June 1997, ex adult Cephaloleia erichsonii Baly on leaf of Calathea , coll. ALAS.

Host identifications — With one exception, the identities of the associated beetles given above are in accord with current molecular studies of their field diet records, which indicate that one haplotype of Chelobasis perplexa sensu stricto is on Heliconia pogonantha . Cephalolaeia erichsonii is a host generalist. Cephaloleia aequilata does not occur at La Selva, and specimens identified as such from there are, in all cases checked by DNA barcodes, C. dilaticollis Baly , which is a host generalist, often on Heliconia , Calathea and other host plants (Carlos Garcia-Robledo, personal communications 2017; Garcia-Robledo et al. 2017).

Etymology — The specific name is a Latinized adjectival combination of ‘duo-obtusi-setis’, referring to two pairs of characteristically blunt-tipped setae Z5 and S5 on the dorsal shield.

Remarks — One female asymmetrically lacks one of setae s2. One female asymmetrically has seta JV4 inserted on the ventrianal shield; otherwise, this setal pair is symmetrically absent, characteristically in all species described of this group.

One female at hand, from under elytra of Cephaloleia erichsonii, Corcovado National Park, May 1997, coll. D. Johnson, has been tentatively identified as Lasioseius duobtusisetis , but is excluded from the type material. It differs primarily from other females by having lengths of most podonotal setae and J1-J3 longer, reaching beyond bases of following setae; yet setae Z5, S5 are thickened, spinelike with blunt tips, and Z4, S4 somewhat thickened but attenuated, which are distinctive of this species.

Two aspects of the sparse collection data are notable, with two records of association with beetles of the genus Chelobasis , and two other records with beetles of two species of Cephaloleia from leaves of a different genus of host plant, Calathea . Tentatively, subject to further studies, we conclude that, at La Selva, Lasioseius duobtusisetis is associated regularly with generalist forms of Chelobasis perplexa and Cephaloleia erichsonii on leaves of various species of Heliconia (and C. erichsonii also on various species of Calathea and Goeppertia ), and also to some extent with another generalist form, Cephaloleia dilaticollis on a similar variety of host plant genera ( Staines & Garcia-Robledo 2014, Garcia-Robledo et al. 2017).

Figures

Figure 10 Lasioseius duobtusisetis n. sp., adult female: A – Idiosoma, dorsal view; B – Detail of denoted dorsal setae; C. Idiosoma, ventral view; D – Gnathotectum; E – Subcapitulum and ventral setae of palptrochanter; F – Spermathecal structures; G – Detail of cheliceral fixed digit, ventral view.

Figure 12 A-D – Leg II, dorsal view (right leg, excluding tarsus, coxa and trochanter), adult males: A—Lasioseius serripes n. sp.; B – L. serripes, detail of ventral setaeon genu and tibia III; C –Lasioseius cassidini n. sp.; D – Lasioseius fuscina n. sp. E, F – Lasioseius duobtusisetis, adult female, tarsus I right leg, dorsal view: E – General aspect without detail of dorsodistal sensorial area; F – Detail of dorsodistal sensorial area. G – Lasioseius serripes, protonymph, tarsus IV left leg; H — Lasioseius sp. undescribed. adult female, tarsus IV right leg, ventral view. (Solid black setae in figures A-G and solid black circles in figures G and H indicate dorsal setae).

Figure 13 Tarsus II, right leg. A, B, H.Lasioseius cassidini n. sp.: A – Adult female, dorsal view; B – Adult male, dorsal view; H — Detail of distal region, lateroventral view. C, D, G.Lasioseius serripes n. sp.: C – Adult female, dorsal view; D – Adult male, anterolateral view; G. Detail of distal region, ventral view. E, F.Lasioseius fuscina n. sp.: E – Adult male, dorsal view; F – Adult female, dorsal view. I —Lasioseius duobtusisetis n. sp., adult female, dorsal view. (Solid black color indicates dorsal setae on segment).

Figure 14 Tarsus IV, adult females, right leg, ventral view: A –Lasioseius cassidini n. sp.; B – Lasioseius serripes n. sp.; C – Lasioseius duobtusisetis n. sp.; D – Lasioseius fuscina n. sp. (solid black circles indicate dorsal setae insertions).