Antennocheles Lindquist & Moraza 2014, gen. nov.
Creators: name: Lindquist, Evert E.
name: Moraza, María L.
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Mesostigmata
Antennochelidae
Antennocheles

description: Genus Antennocheles gen. nov.   
(Figures 1–16)  
 Type species: Antennocheles punctomarginalis sp. nov. Genus based on adult female, male and nymphal material representing two newly described species, as well as a few adults seeming to be of other, undescribed, species.    Diagnosis   
 Nymphs and adults of Antennocheles share with other genera included in the superfamily Ascoidea the series of 18 attributes given above for diagnosis of the family. They are immediately distinguished apomorphically from those of other genera of the families of Ascoidea by the following attributes: chelicerae with greatly elongated shafts capable of being withdrawn entirely into idiosoma and being projected for a distance slightly greater than length of idiosoma outside the body when feeding; subcapitulum with all four pairs of setae aligned longitudinally (rather than hyp-2 and hyp-3 aligned transversely); adult female and male with pair of strongly sclerotized invaginations alongside lyrifissures iv2 on sternal shielding. They are further characterized by: adult dorsal shield entire, nearly holotrichous, but lacking setae z1, z3, s3; marginal (r-R) series lacking setae r1, r6; marginal R- series of setae on soft lateral cuticle on female but variably (usually at least R1) on edge of dorsal shield on male; tritosternum with laciniae fused along most of their length; adult female with well sclerotized sternal, epigynal and ventrianal shields, and with poroids iv3 together with setae st4 on small metasternal plates; adult male with ventral shielding coalesced into a holoventral shield, with line of fusion delineating connection between sternitigenital and ventrianal portions. Leg chaetotactic deficiencies include trochanter I lacking seta ad; femur II lacking al-2, ad-3; genua III–IV lacking pv-1; legs with particular setae thickened, spine-like in form on both female and male include dorsal setae ad-1, pd-1, pd-2 on femora I–II, ad-1, ad-2, pd-1 on femora III–IV, and ventral seta av on femora II–III. Absence of al-2, basal to lyrifissure on femur II, is a highly unusual apomorphy.    Description   
 Idiosomal dorsum. Adult female (Figures 1A, 8A). Dorsal shield entire, without lateral incisions, well sclerotized, with or without a delineated lateral rim alongside the lateral series of s-S setae; surrounding soft cuticle smoothly striate. Dorsal shield with a maximum complement of 33 pairs of setae, including 18 podonotal (j1–j6, z2, z4–z6, s1, s2, s4–s6, r2–r4) and 15 opisthonotal pairs (J1–J5, Z1–Z5, S1–S5); setae z1, z3, s3 absent, and r3 sometimes off shield; dorsal setae heterogeneous in lengths and thickness. 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 lateral cuticle with c.10–12 pairs of marginal (r5, R1–R7, sometimes r3) and submarginal (three or four UR) setae and pair of marginal poroids idRp. Peritrematal plates broadly uniting with dorsal shield anteriorly at level of setae z2–s1; peritremes well developed, reaching to level of, but well lateral to, setae j1; peritremes conspicuously bent or elbowed subapically.   
 Adult male (Figures 3A, 12C). Dorsal shield similar in size, most ornamentation and setation to that of female, except its lateral margins slightly wider to bear setae r5 and variably R1 to R3 and to be more broadly united anteriorly with peritrematal plates; form and relative lengths of shield setae as in female. Extent and form of peritremes as in female.   
 Idiosomal venter. Adult female (Figures 2A,B, 9A,B, E). Tritosternum with laciniae fused for most of length, without basal elaborations (Figure 9E). Ventral shields variably ornamented, well sclerotized. Presternal region smooth or with lineated areas or small platelets (Figures 2A,B, 9A). Sternal shield entire, with strongly developed endopodal extensions between coxae I– II and II – III, that between legs I– II fused to exopodal shield and lacking gland pore (gst1); sternal shield with three pairs of setae, two pairs of poroids, and sometimes with vestiges of gland pores gv1 on posterior margin; shield with pair of prominent, transverse invaginations lateral to poroids iv2, their anterior border well sclerotized (Figure 15B). Intercoxal region with two pairs of small, dense, sigillar areas abutting or integrated into sternal shield lateral margins, one between legs II and one adherent to posterolateral margins between legs II – III and abutting apices of endopodal strips between coxae III – IV. Poroids iv3 together with setae st4 on free, small metasternal plates (Figures 2A, 9A). Endopodal strips between coxae III and IV well developed, free, but with anterior tips sometimes touching sternal shield posterolateral margin. Epigynal shield with hyaline anterior margin between legs III nearly abutting posterior edge of sternal shield, with posterior margin truncate; setae st5 on shield’ s lateral margins, paragenital poroids iv5 on soft cuticle; postgenital furrow with transverse row of four small platelets. Opisthosomatic venter with single pair of large metapodal platelets. Ventrianal shield well developed, wider than long, with anterior margin abutting posterior edge of epigynal shield, and with four or five pairs of opisthogastric setae (JV1 –JV3, ZV2, sometimes ZV3) and two pairs of poroids; paranal setae inserted at mid-level of anus, shorter than postanal seta; shield with pair of prominent gland pores gv3 on lateral margins of anal region, and with cribrum formed as a wide band along posterior margin; other opisthogastric setae (JV4 –JV5, ZV1, ZV3– ZV5) and two pairs of poroids, flanked by posterior pairs of marginal and submarginal setae, on soft cuticle. Peritrematal shield broadly connected with exopodal strip beside coxa IV, with two poroids and one gland pore (gp3) in area behind stigma, and with poroid ip2 and gland pore gp2 along mid-length of peritrematal shield; anteriorly, peritrematal shield with poroid ip1 located ventrolateral to peritreme at level of coxa I, and with gland pore gp1 located dorsolateral to peritreme at level of coxa II (Figure 8A); exopodal strip continuous alongside peritrematal shield by coxae I– III, with extensions between bases of coxae II – III and III – IV, and broadly fused to sternal shield between coxae I– II. Spermathecal apparatus of laelapoid type, sometimes with small section of tubular piece discernibly sclerotized (Figures 1C, 8C).   
 Adult male (Figures 3A,B, 4A–E, 11G, 12A–D). Form of tritosternum and presternal area as in female. Sternitigenital, ventrianal and podal–peritrematal shields consolidated to form holoventral shield; anterior margin of shield, at level of genital opening, prominent; shield with five pairs of setae and three pairs of poroids in the sternitigenital region, and united with endopodal strips between coxae I–II, II–III, III–IV, and with exopodal strips between coxae I–II and behind coxae IV; shield with pair of prominent, transverse invaginations lateral to lyrifissures iv2, formed as in female; shield with a discernible transverse line delimiting sternitigenital from ventrianal region; shield ventrianal region with six or seven pairs of opisthogastric setae (usually JV1–JV4, ZV1, ZV2, sometimes also ZV3) in addition to circumanal setae, four pairs of poroids including paragenital pair, and gland pores gv 3 in anal region; two pairs of metapodal sigilla incorporated in shield; posterior margin of shield broadly rounded, with cribral band as in female; sternitigenital and opisthogastric setae smooth, similar in shape and length as in female (Figures 3B, 12C). Setae JV5 and usually ZV3–ZV5, variably flanked by posterior pairs of marginal setae, inserted on soft cuticle. Exopodal and peritrematal shielding and peritremes as in adult female, except peritrematal union with dorsal shield broader, beginning at level of setae r2 (Figures 3A, 12C).   
 Gnathosoma. Female and male. Gnathotectum with convex anterior margin bearing three elongate, pilose projections (Figures 1D, 8D). Chelicerae as described for the family, capable of complete retraction, yet projection anteriorly for at least idiosomatic length outside the body; chelicerae elongate and slender (Figures 2C, 8E), without any conspicuous process along antiaxial or paraxial lateral surfaces basal to digits. Fixed cheliceral digit fully developed, apposed to movable digit, with typically setiform pilus dentilis, with several teeth restricted to apical half of masticatory surface, and with bifid apical hook; movable digit of female tridentate (basically bidentate, with proximal tooth bifid) (Figure 2C), that of male with one large tooth, and with spermatodactyl directed anteriorly, not recurved basally (Figures 4A–C, 12A,B). Corniculi of female moderately long, slender, parallel (Figure 9C,D), those of adult male similarly formed; internal malae elongate, curving laterally along their length and extending well beyond tips of corniculi (Figures 4D, 9C). Apex of labrum extending slightly beyond tips of corniculi (Figure 9C). Subcapitulum with a pair of pore-like structures at level of insertion of corniculi. Subcapitular setae smooth, in longitudinal, slightly convergent alignment, hyp-1 clearly larger than other pairs. Deutosternum with seven moderately wide rows of denticles, similarly multidenticulate, none connected by lateral margins. Palpi (Figure 9C) with normal setation as described for Gamasina by Evans (1964); palpfemoral seta al with bluntly pointed tip; palpgenual setae al-1 and al-2 more or less spatulate; palptarsal apotele two-tined, with spatulate tips; palptrochanter with inner seta attenuated, whip-like.   
 Legs. Female and male. Legs of moderate length, I and IV no longer than dorsal shield. Legs I slightly thinner, and II slightly thicker, than legs III and IV (Figures 5A–H, 10A–E). Distal margins of coxae I–IV without serrated ridges or spur-like processes. Legs I to IV with pretarsi bearing paired claws of moderate size, inconspicuous paradactyli and rounded pulvilli (Figure 11A,B, D). Leg I tarsus with distinct pedicel bearing pretarsal structures (Figure 11D). Tarsus I with sensilla s inconspicuous, slightly lanceolate (Figure 11F). Legs II to IV with tarsus (excluding pretarsus) about twice as long as tibia. Tarsi II–IV with apical setal processes ad-1, pd-1 short, less than half as long as pretarsi (Figure 11A), and with rounded triangular apical process ventrally (Figure 11B). Setation and their ontogeny on segments of legs I to IV slightly deficient from full complement of Ascidae (as presented by Lindquist and Evans 1965 for Ascini), coxae, 2-2-2-1; trochanters, 5-5-5-5; femora, 12 (2 3/1 2/2 2) – 9 (1 2/1 2/2 1) – 6 (1 2/1 1/0 1) – 6 (1 2/1 1/0 1); genua,13 (2 3/2 3/1 2) – 11 (2 3/1 2/1 2) – 8 (2 2/1 2/0 1) – 9 (2 2/1 3/0 1); tibiae, 13 (2 3/2 3/1 2) – 10 (2 2/1 2/1 2) – 8 (2 1/1 2/1 1) – 10 (2 1/1 3/1 2); trochanter I lacking seta ad; femur II lacking al-2, ad-3; genua III–IV lacking pv-1. Dorsal setae ad-1, pd-1, pd-2 on femora I–II and ad1, ad-2, pd-1 on femora III–IV thickened, spine-like; femora II–III with ventral seta av strongly spine-like (on female and male). Tarsi II–IV with ventral setae v-1 and v-2 spine-like, v-1 thicker and grooved (except pv-1 on tarsus IV no thicker than other ventral setae) (Figure 11B,C); other leg setae simple, not strongly modified on female and male. Male leg setal dimorphism not strongly developed, limited primarily to seta av being somewhat more spine-like or shorter than in female on femora II–III and genua II–IV (Figures 4D, 11G), and tarsus II av-1 asymmetrically more spine-like than pv-1.   
 Deutonymph. Idiosomatic dorsum. Dorsal shield well sclerotized, with lateral incisions reaching to level of setae Z1, and with 30 pairs of setae: 15 pairs (j1–j6, z2, z4–z6, s1, s4–s6, r2) on podonotal region, and 15 pairs (J1–J5, Z1–Z5, S1–S5) on opisthonotal region (Figures 5A, 13A). Lateral soft cuticle with s2, r3–r5 on podonotal region and R1–R6 and two or three pairs of UR –setae on opisthonotal region. Dorsal setae added to protonymphal complement denoted in Figure 13A. Dorsal idiosomatic complement of poroids and gland-pores similar to that in female; paravertical poroids idj1 added to protonymphal complement.   
 Idiosomatic venter. Sternal region with a pair of prominent endopodal pieces between coxae I and II, and sometimes with endopodal fragments between coxae II and III; sternal shield lightly sclerotized, without endopodal extensions between coxae, with two pairs of setae and two pairs of poroids, lacking pair of slit-like invaginations beside poroids iv2 which present on adults; setae st3–st5 and poroids iv3, iv5 inserted on soft cuticle between coxae III and IV (Figures 5B, 13C). Anal shield well sclerotized, clearly wider than long, with circumanal setae, adanal gland pores (gv3) and sometimes poroids ivp and setae JV5 on posterolateral edges of shield at level of posterior margin of anal opening; cribrum as in adult female. Opisthogaster with 10 pairs of ventral setae (JV1–JV5, ZV1–ZV5) flanked by one or two pairs of UR -setae; ventral setae added to protonymphal compliment denoted in Figure 13C. Peritrematal shields not united anteriorly with dorsal shield, and, along with exopodal strips, not developed alongside coxae II–IV (Figure 13B). Peritrematal gland pore gp1 located dorsolateral to peritreme at level of coxae II, and poroid ip2 and gland pore gp2 near midlength of peritreme between coxae II and III; post-stigmatic poroid ip3 adherent to stigma on posterior edge of peritrematal shield, and post-stigmatic gland pore gp3 and poroid ip4 on soft cuticle. Rim of exopodal plate behind coxa IV well delineated, with gland pore gv2 at its medial extremity.   
 Gnathosoma. Gnathotectum, chelicerae, salivary stylets, corniculi, deutosternal structures and palpi similar to those in adult female.   
 Legs. Pretarsi, claws and chaetotaxy of legs I–IV as in adult, including these additions to protonymphal setal complement: av-2 on trochanters I–IV; ad-3 on femur I, pd-2 on femora III–IV; al-2 on genua I–IV, pl-2 on genua I–II, ad-3 on genua I–II, pd-3 on genua I and IV, pl-1 on genu IV, av-2 on genu I, av-1 on genua II–IV, pv-1 on genu II; al-2 on tibiae I–IV, ad-3 on tibia I, ad-2 on tibia II, pd-3 on tibiae I and IV, pl-2 on tibiae I, II, IV, av-2 on tibia I. Form and shape of leg setae similar to those on adult female, but with spine-like setae less strongly formed.   
 Protonymph. Idiosomatic dorsum. Body dorsum with well-sclerotized podonotal and pygidial shields, and with 30 pairs of setae: 11 pairs on podonotal shield, four pairs on lateral soft cuticle beside podonotal shield, seven pairs on interscutal soft cuticle, and eight pairs on pygidial shield. Mesonotal scutellae weakly sclerotized as three pairs of sigilla between setae J1–J2 and Z1–Z2, with anterior pair more strongly formed (Figures 7A, 14A). Body dorsum with complement of 21 pairs of discernible pore-like structures, of which 14 (four on podonotal shield, one on mesonotal scutellae, five on soft cuticle, four on pygidial shield) non-secretory (poroids) and six (two on podonotal shield, one on mesonotal scutellae, one on soft cuticle, two on pygidial shield) superficially appear to be secretory (gland pores). Peritrematal region on each side with five pore-like structures, of which three poroids and two gland pores.   
 Idiosomatic venter. Sternal shield weakly sclerotized, without endopodal extensions, with three pairs of setae and two pairs of poroids (third pair absent). Soft intercoxal cuticle with one or two pairs of faint, oval sigilla alongside sternal shield between bases of legs II and III, and with setae st5 minute or absent between bases of legs IV; paragenital poroids absent. Anal shield well sclerotized, about twice as wide as long, with circumanal setae, adanal gland pores, and cribrum similar in form, size and position to those on deutonymph. Opisthogaster with four pairs of ventral setae and four pairs of poroids on soft cuticle around anal shield. Poroid and gland pore anterior to apex of peritreme between coxae II and III on soft cuticle, and post-stigmatic poroids and gland pore on soft cuticle or small platelet. Rim of exopodal plate behind coxa IV weakly delineated, with gland pore gv2 near its medial extremity (Figures 7B, 14B).   
 Gnathosoma. Form of gnathotectum, elongated internal malae, and other gnathosomatic structures similar to those in deutonymph, except palpi with normal protonymphal complement of setae (see Evans 1964), including only one trochanter seta.   
 Legs. Legs I-II-III-IV with pretarsi, well-developed claws, and with normal protonymphal complement of setae as described for Ascidae by Lindquist and Evans (1965): coxae, 2-2-2-1; trochanters 4-4-4-4 (1 0/2 1); femora 10 (2 2/1 2/2 1) – 8 (1 2/1 2/1 1) – 4 (0 2/1 1/0 0) – 4 (0 2/1 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). Coxa I distal rim with serrated dorsal and posteroventral strips; tarsi II–IV with setae d-1 as long as pretarsus, and ad -2 longer, thinner than other setae, except av-2 similarly attenuate on tarsus IV; dorsal setae ad-1, pd-1, pd-2 on femora I–II and ad-1, ad-2, pd-1 on femora III–IV thicker, slightly spine-like; femur and genu I seta pv-1 also slightly spine-like.    Etymology   
 The name of the genus, masculine in gender, is a Latinized combination of the term antenna, referring to a probing, sensing structure of the head (gnathosomatic) region, and chela, referring to the cheliceral form of this structure.    Distribution and habitats   
 Known at present from material representing just two newly described species (and several specimens of possibly other undescribed species) associated with a limited variety of species of hispine beetles in unfurled leaves of Heliconia in Costa Rica, this genus of mites is anticipated to be highly speciose and widely distributed in tropical regions. Of the two genera of beetles with which the mites are associated, about 200 species of the cephaloleine genus Cephaloleia have been described (http://www.biolib.cz/en/taxon/id796478/), of which nearly 90 species are known from Central America and West Indies (Staines 1996); and, more remarkably, 44 species have been recorded from Costa Rica’ s La Selva Biological Station alone (Staines 2011). Their larvae undergo development mostly in unfurled leaves of Heliconia and Calathea (Strong 1977). In the taxonomically adjacent tribe Arescini, only four species of the neotropical genus Chelobasis are recognized; their larvae are all restricted to unfurled leaves of Heliconia (Strong 1977; Staines 2009). At present, we have no notion as to the range or diversity of hispine beetles with which these mites may be associated. Elsewhere, the Old World tropics have hispine beetles closely related to those discussed here, and their hosts include species also within the Zingiberales (Gressitt 1957, 1963; Strong 1977). The larvae of these beetles genera share a strange, “water-penny”-like morphology, and are distinguished as external, strip-feeding species hidden in rolled leaves, rather than actual leaf miners (Hespenheide and Dang 1999; Santiago-Blay 2004). The host plant genus Heliconia comprises about 100 to 200 species native to rainforests or other wet forests of the tropical Americas and the Pacific Ocean islands west to Indonesia. Furled leaves of another host plant genus, Calathea (family Marantaceae), are known to harbour a few of the less hostspecific species of Cephaloleia with which these mites are associated; indeed, we have one record of an adult male of apparently an undescribed species of Antennocheles from Cephalolaeia belti from this host plant at La Selva Biological Station. This plant genus comprises several dozen species native only to the tropical Americas.    Remarks   
 The absence of seta al-2 on femur II is an unusual apomorphy for Antennocheles, otherwise rarely noted among taxa of free-living mesostigmatic mites. Although a deutonymphal setal addition, al-2 is very stable, and usually the only seta inserted proximal to the lyriform fissure on femur II, among families of Gamasina other than the Parasitidae (Evans 1963). The absence of al-2 on femur II noted by Lindquist and Moraza (2010) for the blattisociid genus Opilioseius is in error, as it is shown in its usual position in their fig. 18. Another deutonymphal seta, v-3, may be situated in that area in the early derivative uropodine families Protodinychidae and Thinozerconidae (Evans 1972; Athias-Binche 1982).   
 A nearly longitudinal, rather than transverse, alignment of hypostomatic setae hyp-2 and hyp- 3 in Antennocheles is found otherwise, to a lesser and less consistent extent, only among some members of the Veigaiidae among the families of free-living Gamasina. In Antennocheles, the transverse interval between setal pair hyp-2 is slightly greater than that between hyp-1, and subequal to that between hyp-3. This arrangement may be correlated with a considerable elongation of the subcapitular platform. Among veigaiids, the interval between pair hyp-3 is clearly greater than that between hyp-2, and the alignment between these two pairs is oblique or more lateral than longitudinal. A hypostomatic setal alignment similar to that of Antennocheles is typical among families of the distantly related cohort Uropodina (Karg 1989; Lindquist et al. 2009).   
The remarkable length of the cheliceral shafts, as well as the capability to project them, such that their digits may reach to points slightly (110%) greater than the entire idiosomatic length (c.625 µm beyond the corniculi), are considered uniquely apomorphic to this taxon among the families of freely living gamasine mites.
description: Published as part of Lindquist, Evert E. & Moraza, María L., 2014, Mites coexistent with neotropical hispine beetles in unfurled leaves of Heliconia: a new genus and family of the Ascoidea (Acari: Mesostigmata: Gamasina), pp. 1611-1651 in Journal of Natural History (J. Nat. Hist.) (J. Nat. Hist.) 48 (27 - 28) on pages 1616-1632, DOI: 10.1080/00222933.2013.877995, http://zenodo.org/record/5193844