Allogynaspis flechtmanni, Krantz, 2018

Krantz, G. W., 2018, Allogynaspis flechtmanni, a new genus and species of the subfamily Macrochelinae (Acari: Mesostigmata: Macrochelidae) from southeastern Brazil, with comments on cheliceral dentition, reproductive strategies, and postepigynal platelets, Zootaxa 4455 (1), pp. 150-160 : 152-157

Allogynaspis flechtmanni n. sp.

( FigS 1–18 )

With the general characteriSticS Of the family aS defined by Mašán (2003) and the tribe MacrOchelini aS defined by EmberSOn (2010).

Adult female ( FigS 1–8 , 14–15 ).

Dorsal idiosoma ( Fig. 1 ) DOrSal Shield averaging 787 (703–917) in length, Width Of Shield at level Of cOxae III averageS 575 (526–648) (n=10), tapered in pOSteriOr pOrtiOn and abruptly narrOWed behind cOxae IV at level Of Setae Z3 (Z2 Of Knee 2017), expOSing cOnSiderable pOSterOlateral and pOSteriOr OpiSthOnOtal integument, Shield With fOveOlate pattern anteriOrly, blending intO rOughly rugOSe area at level Of Setae j4–j6 and diSplaying a punctate-reticulate pattern pOSteriOr tO j6. DOrSal Shield Setae j1 Widely Separated, lOnger than j2 (67 vS 42), Similar in length and OrnamentatiOn tO j3–5; dOrSal Shield Setae z1, j5–6, S2, z5–6, and J2–3, 5 cOnSiderably ShOrter (23– 26) than remaining median, marginal and Submarginal Shield Setae Which, When vieWed dOrSOventrally, are Seen tO be WeaKly clavate With a rOunded tip and Ornamented With a number Of ShOrt hairS antiaxially, paraxial Setal Surface SmOOth and With StrOngly bipectinate marginS ( Fig. 1 , detail). Setae J2 inSerted anteriOr tO pOrOid pairS idm2–3 rather than betWeen them, J3 at level Of Z3 and anteriOr tO pOrOidS idm4 (See Halliday 1986 fOr a diScuSSiOn Of pOSitiOn and identity Of J Setae). VariatiOn in Setal pOSitiOn may Occur bOth betWeen SpecimenS and frOm One Side Of the dOrSal Shield tO the Other; e.g., the diStance betWeen the inSertiOnS Of Seta z2 and the diminutive Seta S2 On the right Side Of the illuStrated Specimen iS greater than On the left Side SO that inSertiOnS Of Setae r2 and r3 Shift clOSer tO the Shield margin, With the inSertiOn Of Seta r3 appearing On the ventrally infOlded margin; WithOut unpaired Setae On OpiSthOnOtal pOrtiOn Of dOrSal Shield aS Seen in SOme Macrholaspis SpecieS ( EmberSOn 2010). With 16 pairS Of lyrifiSSureS and Six pairS Of gland OpeningS aS typical fOr the family ( Knee 2017). Adjacent integumental Setae ShOrter than marginal dOrSal Setae but With Similar rObuSt pilOSity, typically appearing pOinted terminally rather than clavate; idiOSOmatic integument generally Striate-crenulate ( Fig. 15 ), SOmetimeS appearing Spiculate.

Ventral idiosoma ( FigS 2–4 ) Integumental and Shield Setae pilOSe except fOr SmOOth para-analS On ventri-anal Shield; baSe Of tritOSternum ( Fig. 3 ) 2 ½ timeS lOnger than Wide (40), bipectinate laciniae lOng (130), nOrmally prOduced. Sternal Shield ( Fig. 2 ) With baSic OrnamentatiOn pattern Similar tO that Of Macrholaspis opacus (KOch) ( Mašán 2003), denSely punctate except arOund inSertiOnS Of Sternal Setae, WithOut clear reticulatiOn Or linear pattern, pOrtiOn Of Shield belOW pOrOidS iv2 appearing mOre denSely punctate than anteriOr pOrtiOn; Shield margin typically nOtched abOve pOSterOlateral angleS, Or With paired Shield fragmentS laterad frOm Setae St3 When nOtcheS are abSent. Setae St1 lOnger than St2–3 (102 vS 77), clOSely inSerted, WithOut baSal pilOSity; St4 ShOrter (~42), inSerted On Small elliptical metaSternal ShieldS, pOrOid iv3 On anteriOr Shield margin Or in integument abOve it. Epigynal Shield punctate, With WeaKly develOped reticulatiOn, epigynal Setae (St5) Similar in length tO St3, but cOnSiderably mOre pilOSe; pOrOidS iv 5 in integument behind juncture Of Shield With acceSSOry ScleriteS. With a Single pair Of Small, narrOW ScleriteS abOve OpiSthOgaStric Setae Zv1, SOmetimeS With an additiOnal unpaired Sclerite betWeen Zv1 and ventri-anal Shield Setae Jv1 ( Fig. 2 , vS). Ventri-anal Shield narrOWly pyrifOrm and punctate-reticulate, SOmetimeS irregularly nOtched laterally, With three pairS Of pilOSe ventri-anal Setae (44), here cOnSidered JV1–3; para-anal Setae SmOOth and pOStanal Seta StrOngly pilOSe aS in Macrholaspis SpecieS ( Mašán 2003), para-analS SOmeWhat lOnger than ventri-analS (48), pOStanal Seta ShOrter (28) than para-analS, itS baSe Often ObScured by Overhanging anal Shield ridge; cribrum denSely Spiculate, With narrOW para-anal cribral elementS extending anteriOrly tO level Of para-anal Setae; OpiSthOgaStric Setae mOStly lOnger than ventri-analS (56–58), OpiSthOgaSter With three pairS Of pOrOidS ( Fig. 4 , ivO), gland gv2 Well remOved frOm pOSteriOr margin Of cOxae IV. Peritrematic ShieldS fuSed tO dOrSal Shield at level Of cOxae II, peritremeS extend anteriOrly and then anterOdOrSally abOve cOxae I alOng margin Of dOrSal Shield tO a pOSitiOn juSt abOve inSertiOnS Of Setae z1, Stigmata StrOngly prOduced, laterad frOm cOxae III-IV.

Gnathosoma ( FigS 4–5 , 7 ) Lateral elementS Of gnathOtectum ( Fig. 7 ) brOad baSally and tapering diStally, lOnger than diStally undivided elementS Of bifid median prOceSS, Which diSplayS a SerieS Of StrOng medial ventral SpineS ariSing frOm gnathOtectal Stem; cOrniculi ( Fig. 4 , cn) lOng (120), extending nearly tO terminuS Of palpfemur, labrum plumOSe and nearly aS lOng aS cOrniculi, Salivary Styli (SS) diStinct; hypOStOmatic Setae SmOOth, SetifOrm, h1 (100) and h3 (145) greatly exceeding length Of h2 (50); capitular Setae WeaKly pectinate, Subequal in length tO h2, laterOcOxal Setae (lc, van der Hammen 1964) diStinct. Internal malar extenSiOnS Of deutOSternum elOngate, narrOW and StrOngly plumOSe; deutOSternal grOOve With Seven rOWS Of denticleS frOm level Of Setae h1 tO capitular (pOStcOxal) Setae, rOW 1 divided medially and With relatively feW denticleS On each Side (8–10) and Well Separated frOm rOW 2, number Of denticleS in rOW 2 (~50) far greater than in rOW 3 (~34) and decreaSing further in Succeeding rOWS, Size Of denticleS increaSeS in mOre pOSteriOr rOWS; rOW 7 With feW (~20) relatively large denticleS and generally flanKed On each Side by a SerieS Of 4–6 evaneScent denticleS lOcated juSt belOW inSertiOnS Of capitular Setae ( Fig. 4 ), additiOnally With a pair Of large cOnical teeth laterad frOm capitular Setae. Fixed digit Of chelicera ( Fig. 5 ) With a prOximal pair Of adjacent teeth reminiScent Of bidentate tOOth On mOvable cheliceral digit Of femaleS Of mOre highly derived phOretic Macrocheles SpecieS ( Krantz 1998) but WithOut accOmpanying OppOSed ribbed Surface On mOvable digit, additiOnally With a Subterminal tOOth internal tO an elOngate piluS dentiliS, dOrSal Seta ( Fig. 5 , detail) WeaKly Serrate On expanded diStal face, Often appearing SmOOth When Seta iS vieWed dOrSally; mOvable digit With a Small median and a larger, mOre prOximal tOOth OppOSing paired teeth Of fixed digit, internal arthrOdial bruSh (90) cOnSiderably lOnger than external bruSh, cOmpriSed Of Overlying lOng hairS. PalptrOchanter lOng (76), nearly length Of palpfemur; Setae al1 Of palpgenu SpinOSe, ShOrter than al2 (14 vS 26) and SOmeWhat thicKened.

Legs ( FigS 6 , 14 ) mOderately tO extremely lOng, With legS II-IV equaling Or exceeding dOrSal Shield length, leg chaetOtaxy typical fOr family ( EvanS 1963a), genu IV With Six Setae (1 2/1–2/0 0), cOxal Setae pilOSe. LegS I (~725) antennifOrm, narrOWer and SOmeWhat ShOrter than legS II-III, With Simple filifOrm Setae On tarSuS I, Other SegmentS With mOSt dOrSal and lateral Setae diStally pilOSe. TarSal Setae ad1/pd1 Of legS II-IV SmOOth and acuminate, tarSal Setae al1 and pl1 thicKened and peg-liKe baSally, Often narrOWed and acuminate diStally. LegS II (~875) With SmOOth al Setae On trOchanter, femur and genu, Other Setae On theSe SegmentS pilOSe; baSitarSal Setae (al3/pl3, ad3/ pd3) and pd2 On tarSuS II pilOSe, Other tarSal SmOOth, SpinifOrm; Setae Of trOchanterS tO tibiae III-IV mOStly pilOSe diStally; legS III (~910) With tarSal Setae md, mv, pv1, ad2/pv2 and baSitarSal Setae pilOSe, Other tarSal Setae SmOOth. LegS IV lOng (1340–1390), nearly tWice length Of legS I and generally mOre than 1 ½ timeS length Of legS II-III, tarSuS IV ( Fig. 6 ) lOng (500–510), mOre than tWice length Of tibia, tarSal terminuS betWeen Setae al1/pl1 and av1/ pv1 narrOWed and elOngate, diStal pOrtiOn Of Segment Often inWardly curved, With nOrmal cOmplement Of 18 Setae, Of Which av1/pv1, av2/pv2, al2/pl2 and al3/pl3 are SpinifOrm and greatly enlarged, al3 and pl3 WeaKly pectinate; Other tarSal Setae ShOrter, SmOOth (ad1/pd1) Or pilOSe (md, mv, ad3/pd3).

Sperm access system ( Fig. 8 ) With inSeminatiOn pOreS (SOlenOStOmeS) at baSeS Of cOxae III cOnnecting tO lOng (~500), narrOW (<1.0), cOnvOluted tubuli that are eSpecially SinuOuS clOSe tO their OriginS at cOxae III and Which terminate in a median unpaired, rugOSe SacculuS; Sperm duct and Seminal receptacle nOt Seen.

Deutonymph ( FigS 9 , 17 ).

Length Of dOrSal Shield = 629 (548–670), (n=3).

Dorsum ObScure in preparatiOnS at hand, Shield chaetOme, pOrOidOtaxy/adenOtaxy, and nature Of Shield margin nOt clear.

Ventral idiosoma ( Fig. 9 ) Setal OrnamentatiOn aS in female, St 1–4 inSerted On a pOSteriOrly rOunded Shield defined primarily by abSence Of the Striate-crenulate pattern Seen in SurrOunding integument; inSertiOnS Of St 4 marginal, St 5 and pOrOidS iv 5 in Striated integument adjacent tO pOSteriOr Shield margin; With tWO pairS Of OpiSthOgaStric pOrOidS (ivO) internal tO and flanKing Setae Zv2, glandS gv 2 in nOrmal pOSitiOn behind cOxae IV, OpiSthOgaStric regiOn and SetatiOn pattern OtherWiSe unclear in SpecimenS at hand. PeritremeS extend anteriOrly and dOrSally tOWard, but Well ShOrt Of, dOrSal Setae z1.

Gnathosoma . GnathOtectum Similar tO that Of female ( Fig. 7 ) except that lateral elementS are mOre narrOWly attached tO central StalK and narrOW thrOughOut, Similar in length (27) and Width tO elementS Of diStal bifid median prOceSS; deutOSternal grOOve With Seven rOWS Of denticleS betWeen h1 and the capitular Setae, but With capitular rOW WeaKly prOduced, With feWer denticleS in rOW 2 than in adult (~32 vS ~50) and decreaSing tO ~ 26 in rOW 3, and further in Succeeding rOWS; rOW 7 WithOut flanKing denticleS belOW capitular Setae, but With a cOnical tOOth flanKing each capitular Seta aS in female. Chelicerae ( Fig. 17 ) WithOut prOximal adjacent teeth On fixed digit aS Seen in female, median and the mOre prOximal tOOth Of mOvable digit Subequal in Size; cOnditiOn Of dOrSal cheliceral Seta unclear but, baSed On preceding and Succeeding StageS, preSumed tO be WeaKly Serrate On expanded diStal face.

Legs aS in female.

Protonymph ( FigS 10–13 , 16, 18 ).

Length Of idiOSOma =456 (451–462), Width at level Of cOxae III= 339 (325–333) (n=2).

Dorsal idiosoma ( FigS 10 , 16 ) WeaKly Ornamented, Shield marginS WeaKly defined; dOrSal Setal Shape and

OrnamentatiOn Similar tO thOSe Of adult female, Shield chaetOmeS Of 11 pairS Of pOdOnOtalS and eight pairS Of OpiSthOnOtalS nOrmal fOr the inStar ( Halliday 1986, Krantz & RedmOnd 1987), althOugh a Supernumerary Seta OccurS On OpiSthOnOtal Shield Of illuStrated Specimen (viz., Z3 On the left Side in Fig. 10 ); putative Setae J3 With inSertiOnS at level Of pOrOidS idm4.

Ventral idiosoma ( FigS 12, 13 ) Sternal Shield defined by abSence Of integumental Striae, Shield StrOngly narrOWed pOSteriOr tO inSertiOnS Of St3; St1–3 With OrnamentatiOn aS in later StageS, With pilOSity largely cOnfined tO diStal pOrtiOnS; St5 ( FigS 12, 13 ) ShOrt, palmate, With 4–6 diStal “fingerS” and inSerted in integument behind Sternal Shield. Anal Shield Small, Ovate, WeaKly defined, anal valve cOmplex Wider than lOng (30x20); OpiSthOgaSter With Only fOur ObServed pairS Of Setae (ventri-analS Jv1–3 and Jv5), in additiOn tO the StrOngly prOduced, SmOOth paraanalS and pilOSe pOStanal Seta; With tWO pairS Of pOrOidS (ivO) laterad frOm Jv2. Stigmata abOve anteriOr margin Of cOxae IV, peritremeS ShOrt (35), extending laterad frOm Stigmata and curved anteriOrly.

Gnathosoma aS in female except fOr the fOllOWing: gnathOtectum ( Fig. 11 ) With diStal bifid prOceSS aS in later StageS, but lateral elementS abSent; deutOSternal grOOve With Only Six rOWS Of denticleS betWeen Setae h1 and capitular Setae, rOW 2 With feWer denticleS than in deutOnymph (~22 vS ~32) and decreaSing in Succeeding rOWS. WithOut ancillary denticleS belOW capitular Setae, but With paired cOnical teeth flanKing capitular Setae aS in later StageS. Fixed digit Of chelicera ( Fig. 18 ) WithOut adjOining prOximal teeth, Subterminal, median and prOximal teeth Of mOvable digit WeaKly develOped; dOrSal cheliceral Seta WeaKly Serrate On brOadened diStal face.

Legs ( Fig. 16 ) Similar tO thOSe Of later StageS, including preSence Of enlarged, SpinifOrm Setae On tarSuS IV, Seta mv abSent; viSible Setal Segmental chaetOmeS cOrreSpOnding tO thOSe preSented by EvanS (1963a) fOr prOtOnymphal Pergamasus .

Figures

FIGURES 1–5. Allogynaspis flechtmanni adult female. 1. Dorsal shield, with detail of antiaxial surface of seta j3; 2. Ventral shields and associated glands and poroids; 3. Tritosternum; 4. Venter of gnathosoma; 5. Chelicera, with detail of dorsal seta.

FIGURES 6–13. Allogynaspis flechtmanni. 6. Adult female, tarsus IV, ventral aspect; 7. Adult female, gnathotectum; 8. Adult female, sacculus and attached tubuli; 9. Deutonymph, sternal region; 10. Protonymph, dorsum; 11. Protonymph, gnathotectum; 12. Protonymph, venter; 13. Protonymph, detail of seta st5.

FIGURES 14–18. Allogynaspis flechtmanni. 14. Adult female, ventral habitus of female (chelicerae excised); 15. Adult female, detail of dorsal shield seta S4 and integumental seta R4. 16. Protonymph, dorsal habitus; 17. Deutonymph; chelicera; 18. Protonymph, chelicerae.