Calyptoseius, Lindquist & Moraza, 2016

Lindquist, E. E. & Moraza, M. L., 2016, A new genus of mites of the subfamily Platyseiinae associated with Azteca ant galleries in Cecropia trees in Costa Rica (Acari: Mesostigmata: Blattisociidae), Acarologia 56 (3), pp. 293-319 : 296-305

Calyptoseius , new genus

( Figures 1-8 )

Type species: Calyptoseius longinoi new species. Monotypic.

Diagnosis — Adults (and deutonymphs) of the new genus are immediately distinguished autapomorphically from those of other platyseiines as well as from other members of the superfamily Phytoseioidea in having the tarsi of legs II to IV each with four elongated, strap- or whip-like setae (ad-2, pd-2, al-2, pl-2); those of other platyseiine genera have at most three setae (ad-2, pd-2, pl-2) strap-like on tarsus II and two (ad-2, pd-2) strap-like on tarsi III- IV. They are also distinguished apomorphically from other platyseines in having the third pair of sternal setae alone clearly longer than the other sternal setae, the dorsal and lateral setae of most leg segments collectively palmate-ciliated, and the male having a discrete ventral shield between the sternitigenital and anal shields. They are distinguished plesiomorphically from those of other platyseiines in having 12 and 11 setae on the femur of legs I and II, respectively (by retaining pv-2), and 11 and 9 setae on the genu of legs II and III (by retaining pv- 1). Among the genera of Platyseiinae , Calyptoseius shares with Cheiroseiulus the following apomorphic attributes: opisthogaster of female and male with an anal shield; gland pores gv3 on soft integument adjacent to anal shield; and legs I to IV with paradactyli and medial lobe of pulvillus untapered, blunt-tipped. However, adults of Calyptoseius are similar plesiomorphically to those of Cheiroseius in having a holotrichous dorsal shield with 21 to 23 pairs of setae on the podonotal region and 15 to 18 pairs on the opisthonotal region, and in having 10 setae on tibia II (seta pd-2 present).

Description:

Idiosomatic dorsum — Adult female. Dorsal shield entire, without lateral incisions, moderately well sclerotized, surrounding soft integument smoothly striate. Dorsal shield with complement of 38 pairs of setae, including 23 podonotal pairs (j1- j6, z1-z6, s1-s6, r2-r6) and 15 opisthonotal pairs (J1- J5, Z1-Z5, S1-S5), sometimes r6 asymmetrically off shield; setae collectively of similar, smooth, attenu-

Acarologia 56(3): 293–319 (2016)

ated form and lengths except j1 shorter, palmateserrate, and J5 shorter, slightly spiculate. Dorsal shield with complement of 23 pairs of discernible pore-like structures (nine podonotal, 14 opisthonotal), of which seven pairs (four podonotal, three opisthonotal) superficially appear secretory (gland pores) and 16 pairs (five podonotal, 11 opisthonotal) non-secretory (poroids). Soft surrounding cuticle with six or seven pairs of R -marginal setae and two pairs of marginal poroids including idRp, lacking UR -setae. Peritrematal plates broadly united anteriorly with dorsal shield to level of setae r3; peritremes well developed, reaching to level between setae s1 and z1.

Adult male — Dorsal shield with form and sclerotization as in female except more broadly united to peritrematal shields at level of setae r4. Dorsal shield with complement and form of setae similar to that of female, except with usually two more pairs of marginal setae including r6 and sometimes R1. Lateral soft cuticle with five or six pairs of R - marginal setae. Peritremes as in female.

Deutonymph — Dorsal shield with short lateral incisions, similarly sclerotized as in adults. Dorsal shield with complement of 30 pairs of setae, including 15 podonotal and 15 opisthonotal pairs, of similar length and shape as in adult; 14 pairs of dorsal setae on surrounding soft integument (z1, s1, s2, r2- r6, R1-R6). Dorsal complement of discernible porelike structures as in adult. Peritrematal shields free, limited to a narrow strip with two widened areas, one at anteriormost dorsal region bearing gp1, one at medial area bearing gp2, ip2; a short poststigmatic extension with ips1; gland pore gp3 and poroid ip3 on a tiny platelet on soft cuticle behind stigma; peritremes well developed, narrow, extending to level of setae s1.

Protonymph — Dorsal shields weakly sclerotized. Podonotal shield with 11 pairs of setae (j1- j6, z2, z4, z5, s4, s5) similar in moderate length and simple form, except j1 shorter palmate-spiculate, flanked by four pairs of setae (r2, r3, r5, s6) on soft lateral cuticle; pygidial shield with eight pairs of setae (J3-J5, Z3-Z5, S4, S5) of similar size and simple form except J5 shorter, slightly spiculate, and three pairs of pore-like structures discernible (two pairs of gland pores, one pair of poroids); soft cuticle between shields with seven pairs of dorsal setae (J1, J2, Z1, Z2, S2, S3, R1). Peritrematal shields fragmented and free, and peritremes short, alongside coxae III and IV; poroids gp2 on small peritrematal platelet, gp3, ip3 on soft cuticle behind the stigma.

Idiosomatic venter — Adult female. Tritosternum with pilose laciniae free for most of length, their fused section and base without elaborations ( Fig. 1E ). Ventral shields unornamented, weakly sclerotized. Presternal region without platelets. Sternal shield entire, with well developed endopodal extensions between coxae I-II bearing gland pore gvb distally, and with those poorly developed between coxae II-III; shield with three pairs of setae, st3 the longest, and two pairs of lyrifissures; setae st4 and lyrifissures iv3 on soft cuticle ( Fig. 2A ). Endopodal strips between coxae III and IV free, weakly defined, distant from sternal shield. Epigynal shield with its convex hyaline anterior margin between legs II-III abutting or barely overlapping posterior edge of sternal shield, its posterior margin slightly convex; setae st5 on shield’s lateral margins, paragenital poroids iv5 on soft cuticle; postgenital furrow present, its strip of transverse platelets hardly discernible. Soft opisthogastric integument with small, undivided metapodal platelets, five pairs of setae (JV1, JV2, JV5, ZV1, ZV2), and four pairs of poroids, flanked by posteriormost two pairs of R -setae. Opisthogaster with anal shield ovoid, with paranal setae inserted at midlevel of anus, and similar in size to postanal seta; anal valves with euanal poroids; shield with a well-developed cribrum behind level of postanal seta; gland pores gv3 on soft cuticle well removed from shield. Peritrematal shield connected with exopodal strips curving behind coxa IV, with two poroids (ip3, ips1) and one gland pore (gp3) in area behind stigma; shield with poroid ip2 and gland pore gp2 along widened area below level of setae r3-r4 ( Figs 1A , 2B ). Exopodal strip weakly developed freely alongside peritrematal shield by coxae II-IV, with small extensions between I-II, II-III, III-IV (not shown in figures). Spermathecal apparatus of phytoseioid-type, with minor duct emanating from embolus near base of sclerotized calyx, and with major duct leading from calyx to solenostome between coxae III-IV ( Figs 8A, B ).

Adult male. Aspects of tritosternum and presternal area as in female. Ventral shields unornamented, weakly sclerotized. Sternitigenital shield with five pairs of setae and three pairs of poroids, and fully contiguous with well developed endopodal extensions between coxae I-II, II-III, and III-IV ( Fig. 3A ); relative lengths of sternal setae as in female. Opisthogaster with discrete ventral shield bearing one or two pairs of setae (ZV1 laterally and JV1 on or barely off posterior margin); soft opisthogastric integument with metapodal platelets as in female, four or five pairs of setae (JV2, JV5, ZV2, ZV3, sometimes JV1), and three pairs of poroids, flanked by posteriormost two pairs of R -setae. Opisthogaster with discrete anal shield, with aspects of its form, three circumanal setae, and cribrum as in female. Posteriorly and laterally, peritrematal shield, peritreme, and exopodal strip as in female.

Deutonymph. Tritosternum and presternal area as in female. Ventral shields unornamented, weakly sclerotized. Sternal shield with four pairs of setae and three pairs of poroids (iv3 present); setae st5 and poroids iv5 on soft cuticle; shield without endopodal extensions, but endopodal fragment well developed, apically with gland pore gvb, between coxae I and II; endopodal fragments between coxae II-III indiscernible ( Fig. 6B ); narrow rim of exopodal plate behind coxa IV with gland pore gv2. Opisthogaster similar to female; soft integument with five pairs of setae, three pairs of poroids, and gland pore gv3. Anal shield with aspects of its form, three circumanal setae and cribrum as in female.

Protonymph. Tritosternum and presternal area as in deutonymph. Sternal shield weakly delineated, with three pairs of setae and one pair of poroids (iv1 indiscernible); endopodal extensions between coxae I-II hardly discernible but gvb present ( Fig. 7B ); intercoxal soft cuticle with tiny setae st5 between bases of legs IV. Opisthogaster with well delineated anal shield surrounded by soft integument with four pairs of setae (JV1, JV2, ZV2, JV5) and two pairs of discernible pore-like structures including gv3. Anal shield with structures much as in deutonymph, except postanal seta somewhat shorter than paranal setae.

Gnathosoma — Gnathotectum with three denticulate branches ( Fig. 1C ), median branch not elongated. Chelicera slender, its shaft moderately elongated (but dimorphically shorter on male), without any conspicuous process along antiaxial or paraxial lateral surfaces near bases of the digits; fixed digit with setiform pilus dentilis and row of few small teeth along apical one-third of masticatory surface, and an offset tooth (gabelzahn) subapically ( Figs 2C, D ); movable cheliceral digit of female and nymphs bidentate, with margin of arthrodial envelope smooth; movable digit of male unidentate with spermatodactyl digitiform, free to its connection at base, directed anteriorly and somewhat ventrally. Deutosternum with usually seven (variably eight) transverse rows of denticles, anterior five rows similarly moderately wide, sixth and seventh rows somewhat wider; all rows similarly spaced from one another, multidenticulate and indistinctly connected by lateral edges. Corniculi normal in form, entire, well separated from base to apex, with blunt-tipped salivary styli appressed to dorsal cornicular faces; male with blunt lobe medial to insertion of corniculus ( Fig. 3C ); internal malae normal in form, somewhat longer than corniculi, fimbriated laterally, not subdivided. Subcapitular setae similarly smooth, attenuate, hp1 slightly longer, more whip-like than hp3 and pc, which clearly longer than lateral hp2 ( Fig. 1D ). Palpi with normal setation as described for Gamasina by Evans (1964); palptrochanter with inner seta longer, more whip-like, than outer seta; palpfemur with seta pd palmate, spiculate, like most dorsal setae on legs, and with al spatulate; palpgenual setae al-1 and al-2 more or less spatulate; palptarsal apotele two-tined ( Figs 1F, G ).

Legs — Legs I to IV with pretarsi bearing paired claws, those of II-IV with blunt paradactyli, pulvillae with three blunt lobes, and one slender ventral acuminate lobe ( Figs 5C, D ). Legs I the thinnest, legs IV especially elongate and stronger; legs II to IV with tarsus two to three times as long as tibia. Distal margins of coxae I-IV lacking serrations or spurlike processes. Tarsus I without markedly elongated setae apically, and with sensilla s conspicuous, its apex slightly lanceolate ( Fig. 5A ). Tarsi II-IV each with apical setal processes ad-1, pd-1 as long as pretarsi, and with four elongated, strap- or whip-like setae, al-2 and pl-2 nearly as long as ad- 2 and pd-2. Complement of setae on segments of legs I-II-III-IV differs in several respects (indicated by boldface) from that of other Platyseiinae as presented by Lindquist & Evans (1965): coxae, 2-2-2-1; trochanters, 6-5-5-5; femora, 12 (2 3/1 2/ 2 2) – 11 (2 3/1 2/ 2 1) – 6 (1 2/0 1/1 1) – 6 (1 2/0 1/1 1); genua, 13 (2 3/1 3/2 2) – 11 (2 3/1 2/ 1 2) – 9 (2 2/1 2/ 1 1) – 9 (2 2/1 3/0 1); tibiae, 13 (2 3/1 3/2 2) – 10 (2 2/1 2/1 2) – 9 (2 1/1 2/1 2) – 10 (2 1/1 3/1 2); femora I and II each with a third ventral seta (pv-2, sometimes denoted as v-3) added to deutonymph; genua II and III each with deutonymphal seta pv-1, genu IV lacking pv-1; tibia II with 10 setae, pd-2 present ( Figs 4 A-D). Other than on tarsi, dorsal and lateral leg setae collectively palmate-spiculate, and ventral setae mostly smooth. Legs of male without conspicuous dimorphically modified setae; dorsal setae of tibiae I and II smooth; dorsal setae of genua I and II less palmate-spiculate.

Immature instars. Structures of legs and shapes of setae in nymphal instars, and leg chaetotaxy of deutonymph as in adults. Leg chaetotaxy of protonymph typical of general pattern presented for free-living Gamasina by Evans (1963): coxae, 2- 2-2-1; trochanters, 4-4-4-4; femora, 10 (2 3/1 1/1 2) – 8 (1 2/1 2/1 1) – 5 (1 2/1 1/0 0) – 4 (1 2/0 1/0 0); genua, 8 (1 2/1 2/1 1) – 6 (1 2/0 2/0 1) – 6 (1 2/0 2/0 1) – 5 (1 2/0 2/0 0); tibiae, 8 (1 2/1 2/1 1) – 7 (1 1/1 2/1 1) – 7 (1 1/1 2/1 1) – 7 (1 1/1 2/1 1).

Etymology

The genus name is a Latinized combination of the term calypto, based on the Greek kalyptos, meaning ’concealed’ or ’covered’, and seius or sejus, a Roman surname used by many authors to form names for genera of mesostigmatic mites. The name is masculine in gender, and is intended to refer to the hidden niche in which these mites are found associated with ants in Cecropia trunks.

Figures

FIGURE 1: Calyptoseius longinoi n. sp., adult female: A – Idiosoma, dorsal view; B – Detail of denoted dorsal setae; C – Gnathotectum; D – Subcapitulum; E – Tritosternum; F – Palp, dorsolateral view; dorsal setae in solid black color; G – Detail of palptarsus.

FIGURE 2: Calyptoseius longinoi n. sp., adult female: A – Idiosoma, ventral view; B – Detail of proximal region of peritrematal shield and its fusion with exopodal strip; C – Chelicera, anterolateral view; D – Fixed cheliceral digit, lateral detail of distal region; E – Dorsum of fixed digit, with detail of dorsal cheliceral seta.

FIGURE 3: Calyptoseius longinoi n. sp., adult male: A – Idiosoma, ventral view; B – Idiosoma, dorsal view; C – Subcapitulum; D – Chelicera and spermatodactyl, lateral view; E – Detail of cheliceral digits and spermatodactyl.

FIGURE 4: Calyptoseius longinoi n. sp., legs I-IV excluding tarsus, adult female: A – Leg I, dorsal view; B – Leg II, dorsal view; C – Leg III, anterolateral view; D – Leg IV, anterolateral view. Dorsal setae in solid black color.

FIGURE 5: Calyptoseius longinoi n. sp., adult female: A – Tarsus I, detail of distal seta "s"; B – Tarsus I, dorsal view; C – Tarsus II, dorsal view; D – detail of pretarsus, ventral view; E – Detail of basitarsus III; F – Tarsus IV, anterolateral view and detail of dorsal strap-like seta. Fig. B, solid black circles refer to ventral setae; Figs. C-F, dorsal setae in solid black color.

FIGURE 6: Calyptoseius longinoi n. sp. deutonymph: A – Idiosoma, dorsal view; B – Idiosoma, ventral view.

FIGURE 7: Calyptoseius longinoi n. sp. protonymph: A – Idiosoma, dorsal view; B – Idiosoma, ventral view; C – Detail of corniculi and salivary styli; D – Detail of apex of subcapitulum.

FIGURE 8: Calyptoseius longinoi n. sp.: A, B – Female, spermathecal structures, different views, arrow pointing to diverticular lobe; C-E – Male, spermatodactyl, different views.