Tanyscelis verrucula (Froggatt)

Hodgson, Chris, 2020, A review of neococcid scale insects (Hemiptera: Sternorrhyncha: Coccomorpha) based on the morphology of the adult males, Zootaxa 4765 (1), pp. 1-264 : 97-100

Tanyscelis verrucula (Froggatt) ( Fig. 39 )

Opisthoscelis verrucula Froggatt, 1894, 338 . Type data: Australia, New South Wales, Bathurst, Napoleon Reef, on Eucalyptus sp., by W.S.C. Ross and W.W. Froggatt. Syntypes, female. Type depository: ACU.

Tanyscelis verrucula (Froggatt) ; Hardy & Gullan 2010, 65. Change in combination.

Material examined. Australia, Bathurst, New South Wales, on Eucalyptus sp., no date, Froggatt? coll. ( BMNH, ex Brain coll.; 1945–121): 1/6ad ♂♂ (mainly in rather poor condition; none properly cleared and all mounted in rather distorted positions. Nonetheless, a composite description was possible.)

Mounted material: rather large, total body length 2.5–3.2 mm; however, about half this length is highly extended abdomen whose posterior 4 segments + penial sheath represent half the insects length. Antennae 9-segment- ed, rather long, about 1/6th total body length. Body rather setose, most setae fs and rather long and flagellate, those on legs and antennae similar; length of fs on antennae about four times width of flagellar segments. Wings about 3/4 total body length and possibly 3/7th as wide as long.

Head: appearing rather elongate oval in dorsal view on mounted specimen but probably with a distinct posteroventral bulge for ventral simple eyes; width across genae about 277 μm. Median crest (mc) slightly sclerotised, not reticulated but with a few faint ridges; postoccipital ridge (por) well developed; with (on each side) 7–14 fs each 43–50 μm long + 3–9 hs dorsal head setae (dhs) + 8–12 small simple pores just anterior to lateral arms of mid-cra- nial ridge (lmcr). Mid-cranial ridge: dorsal ridge (dmcr) quite long, extending posteriorly to between dorsal simple eyes (dse); ventral ridge (vmcr) with well-developed arms (lmcr) extending laterally to each scape, and with a thin medial ridge extending a short distance towards ventral simple eyes (vse); area laterad to ventral mid-cranial ridge not apparently sclerotised or reticulated, with 8 or 9 fs + 0 or 1 hs ventral mid-cranial ridge setae (vmcrs) on each side. Genae (g) unsclerotised and not reticulated; with a group of about 8 fs + 1 hs genal setae (gs) on each side near post-occipital ridge. Eyes: with two pairs of round simple eyes; dorsal eyes (dse) marginally broader than ventral eyes (vse), each dse about 30 μm wide, each vse 25–28 μm wide. Ocelli (o) distinct, not touching post-ocular ridge, each about 11 μm wide. Ocular sclerite (ocs) sclerotised with concentric striations around simple eyes. Preocular ridge (procr) absent, but with an articulatory process present on ocular sclerite for each scape. Postocular ridge (pocr) strongly developed, extending dorsally past each ocellus and almost reaching post-occipital ridge medially on dorsal surface. Dorsal ocular setae (docs) probably absent. Ventral head setae (vhs) abundant, mainly long fs with an occasional hs: common all round each ventral eye, extending to close to mouth posteriorly and dorsally to around each ocellus. Preoral ridge (pror) poorly developed or absent, but with a slightly sclerotised transverse area ventral to ventral cavity. Cranial apophysis (ca) rather short and bifid, about 23 μm long.

Antennae: 9-segmented, filiform, each segment rather elongate and narrow, each 1.5 mm long (ratio of total body length to antennal length 1:0.52). Each segment with numerous very long fs, each about 4 times width of segment. Scape (scp): 45–50 μm long, 60–70 μm wide, with 1 fs + 6 hs. Pedicel (pdc): length 70 μm, width 45–54 μm; without ridges or reticulations; with 15 fs + 3 hs. Segments III–IX all 8–10 μm wide: fs 41–47 μm long; lengths of segments (μm): III 207–224; IV 198–240; V 227–248; VI 277–282; VII 202–224, and VIII 149–178; approximate number of setae per segment: III 21–24 fs + 1 hs (no sensilla basiconica detected); IV 22–28 fs + 0–2 hs; V 30–31 fs + 1 hs; VI 32–34 fs + 2 hs; VII 23–26 fs + 2 hs, and VIII 11–22 fs + 2 hs + 1 strong bristle near distal end. Segment IX: length 91–108 μm; not constricted apically; with 3 capitate setae (cap), 8–13 fs, possibly no sensilla basiconica, and with 3 large + 2 small bristles.

Thorax. Prothorax: pronotal ridge (prnr) well-developed, probably fused dorsally, broadening ventrally into a strongly ridged lateral pronotal sclerite (prn); pronotal ridge extending ventrally, where it articulates with a bend in cervical sclerite; lateral pronotal setae (lpns) absent. Medial pronotal setae and post-tergital setae probably absent but this area unclear. Post-tergites present but mainly hidden under leading edge of mesothorax. Sternum (stn 1) not sclerotised but with radial ridges; transverse ridge rather weak, strongest laterally; median ridge absent; with numerous prosternal setae (stn 1 s) (possibly about 22 fs + 4 hs on each side) extending laterally anterior to anterior spiracle; with about 5 fs anteprosternal (astn 1 s); antemesospiracular setae (am 2 s) present (number included with prosternal setae above).

Mesothorax: prescutum (prsc) forming a distinct anterior bulge; dorsal part on mounted specimens 127–150 μm long; 196–205 μm wide; sclerotised but slightly nodulated; prescutal ridges (pscr) and prescutal suture (pscs) absent but with a lateral and posterior groove. Scutum (sct): median area not membranous but strongly sclerotised, without reticulations, bordered by two bands of small setae, each band with 13–17 hs; marginal areas of scutum sclerotised and radially striated and with 0 or 1 hs on each side; area of scutum laterad to scutellum sclerotised but not striated, also with 0 or 1 hs on each side; prealare ridge apparently absent. Scutellum (scl) 256–286 μm wide, 78–83 μm long; with an inverted U-shaped scutellar ridge (sclr) and a large foramen; scutellar setae (scls): 0–2 hs on each side; posterior notal wing process (pnp) very short. Basisternum (stn 2) 355–370 μm wide, 198–230 μm long; without a median ridge (mdr), but bounded anteriorly by a strong marginal ridge (mr) and posteriorly by strong precoxal ridges (pcr 2); with many (40+) basisternal setae (stn 2 s) (mainly fs but with some hs) spread over entire surface; lateropleurite (lpl) fairly narrow, each with a thin sclerotised extension from marginal ridge anteriorly and traversed lengthwise by a short ridge; furca (f) well developed, broadly-waisted, arms very divergent and extending about 2/3rds to marginal ridge. Mesopostnotum (pn 2) and postnotal apophysis (pna) well developed, latter quite deep. Area bounded anteriorly by scutellum and laterally and posteriorly by mesopostnotum not sclerotised. Mesepisternum (eps 2) not reticulated but possibly with 2 fs on dorsal surface; subepisternal (ser) ridge well developed. Postalare (pa) not reticulated anteriorly; without postalare setae (pas). Mesothoracic spiracle (sp 2): peritreme 35 μm wide. Postmesospiracular setae (pm 2 s): in a broad band of about 60 fs + 6 hs extending laterally almost to subepisternal ridge. Tegula (teg) present, with 5–6 hs tegular setae (tegs) on each side.

Metathorax: with about 2 fs + 3 hs metatergal setae (mts) on each side. Dorsospiracular setae (dss): about 7 fs + 1 hs. Dorsal part of metapleural ridge (plr 3) absent and without a suspensorial sclerite (ss). Ventral part of metapleural ridge well developed; episternum (eps 3) mildly sclerotised, with about 4 or 5 fs + 0 or 1 hs postmetaspiracular setae (eps 3 s) on either side. Metepimeron (epm 3) sclerotised and elongate, broadening posteriorly apparently with a pore; without setae. Antemetaspiracular setae (am 3 s): perhaps 7 fs. Metathoracic spiracle (sp 3): width of peritreme 42 μm. Metasternum (stn 3) with about 40 fs anterior metasternal setae (amss) and perhaps 11 fs + 1 hs posterior metasternal setae (pmss).

Wings: hyaline, possibly 1800–1875 μm long,750 μm wide (ratio of length to width 1:0.42; ratio of total body length to wing length 1:0.63); alar lobe (al) and alar setae (als) absent. Hamulohalteres absent.

Legs: prothoracic legs possibly marginally longest. Coxae (cx): I 120–127; II 133–140; III 152–159 μm long; setae of coxa III: about 24 fs + 2 hs; long apical setae apparently absent. Trochanter (tr) + femur (fm): I 444–477; II 406–438; III 431–451 μm long; trochanter III with about 12 fs + 2 hs; long trochanter seta not differentiated; femur III with about 68 fs + 12 hs. Tibia (ti): I 476–495; II 425–447; III 470 μm; tibia III with a total of about 110 setae, mainly fs and hs, a few possibly becoming spur-like on distal third of leg; with 2 or 3 stout apical spurs (tibs), length 10–12 μm. Tarsi (ta) 1 segmented; lengths: I 152–175; II 152; III 159 μm long (ratio of length of tibia III to that of tarsus III 1:0.34); tarsus III with about 40 setae, mainly fs; tarsal spurs not differentiated; tarsal campaniform pore present; tarsal digitules (tdt) slightly longer than claw with small capitate apices. Claws (c) rather small, shorter than width of tarsi, with an inconspicuous denticle; length: III 29 μm; claw digitules (cdt) slightly longer than claw, with minute apical knobs.

Abdomen: segments I–VIII: segments I–III about equally wide but segments IV–VIII becoming progressively narrower and elongate, so that segments IV–VIII + penial sheath equal half total body length; tergites (at) and sternites (as) of I–VIII possibly slightly sclerotised and elongately ridged throughout length. Caudal extensions (ce) on segment VII and VIII absent. Setae not obviously separated into groups, appearing more or less as a complete ring around each segment on segments I to V (i.e., separation into dorsal abdominal, ventral abdominal and pleural setae not possible), segments I to V with numerous fs and a few hs, segments VI–VII lacking fs, with a total of about 5 or 6 hs on segment VIII. Glandular pouches and glandular pouch setae absent.

Genital segments: penial sheath (ps) of rather variable length (343–420 μm; ratio of total body length to penial sheath length 1:0.13) but only narrowing slightly towards apex (width at base 29–30 μm), divided into two: (i) seg- ment IX, lightly sclerotised with elongate striations and with a slightly oval anal opening on dorsal surface plus a pair of setae on dorsal surface at posterior end, and (ii) style, not striated and not obviously sclerotised. Aedeagus apparently rather narrow and deep (blade-like), extending almost entire length of posterior half of penial sheath (length 145–176 μm); with a short (13 μm long) sclerotisation at anterior end, probably representing a short basal rod (bra). Style with a total of about 13 longish setae (pss) and with a group of small sensilla (psp) near apex.

Comment. The males of T. verrucula are immediately recognisable by their elongate abdomen, which has presumably evolved to enable the males to mate with the females deep inside a gall. The structure of the penial sheath is also apparently unique, appearing to be barely differentiated from the previous abdominal segments and not heavily sclerotised (somewhat similar in Cystococcus spp.).

Theron (1968) described the main cuticular structures of two Tanyscelis (as Opisthoscelis ) spp. Hardy & Gullan (2010) considered that it was likely that these two species were O. spinosa Froggatt and O. maculata Froggatt , now Tanyscelis spinosa (Froggatt) and T. maculata (Froggatt) ( Hardy & Gullan 2010) . The above description of T. verrucula agrees quite closely with that given by Theron for the other species but possibly differs in the following details: (i) the apodeme-like structure on the anterior margin of the scutum, similar to that found in some pseudococcids and eriococcds, could not be detected; (ii) the lateropleurite appeared to be traversed by only one narrow ridge (as on Apiomorpha ) rather than 2; (iii) no tergites could be detected on abdominal segments I and II; (iv) no minute apodemes were detected on the dorsal surface of the penial sheath, but (v) what is possibly a very short basal rod was present at the anterior end of the aedeagus.

Figures

FIGURE 39. Tanyscelis verrucula (Froggatt). Macropterous male. (Eriococcidae, Gondwanan group). Where A=cranial apophysis and X=pores on head.