Aclerda distorta Green, 1909

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 : 203-205

Aclerda distorta Green ( Fig. 79 )

Aclerda distorta Green 1909 , 290. Type data: Sri Lanka: Pundaluoya, Yatiyantota and Udagama, on Arundinaria sp. Syntypes, female. Type depository: BMNH.

Material examined. Sri Lanka, Pundaluoya, on Arundinaria sp. ( Poaceae ), March 1897, E.E. Green ( BMNH): 1/1ad ♂ (in good condition).

Mounted material: quite large, total body length 1.76 mm; width across triangular plates 0.37 mm; long and slender. Without convex pores (cp).

Head: approximately diamond-shaped in dorsal view; about 220 μm long; width across genae 286 μm. Median crest (mc) with some striations; with 1 pair hs dorsal head setae (dhs) posteriorly. Dorsal mid-cranial ridge absent; ventral mid-cranial ridge (vmcr) absent but area reticulated; without ventral mid-cranial ridge setae (vmcrs). Genae: genal setae (gs): 1 hs posterior to each dorsal eye. Eyes: two pairs of round simple eyes, subequal in size (25–27 μm wide). Ocelli (o) present laterally; small. Preocular ridge very short, perhaps extending dorsally from each scape towards dorsal eyes. Ocular sclerite (ocs): each polygonally reticulated, each reticulation without inner microridges. Postocular ridge (pocr) absent. Dorsal ocular setae (docs) absent. Ventral head setae (vhs): 3 or 4 hs just posterior to each scape. Cranial apophysis (ca) 131 μm long anterior to tentorial bridge; apex with many fine digitations.

Antennae: total length 1.3 mm long (ratio of total body length to antennal length 1:0.75). Scape (scp): 41–46 μm long, 62 μm wide; with 2 hs dorsally. Pedicel (pdc): length 33 μm, width 39–41 μm; with 1 hs (no sensilla placodeum detected). Segments III–X each 14–19 μm wide: fs each 28–35 μm long; lengths of segments (μm): III 170–174; IV 174–186; V 190–207; VI 190; VII 160–166; VIII 136–141 and IX 103–112; setae rather few: approximate number per segment: III 2 or 3 fs +?0 hs + 3 sensilla basiconica; IV 9 or 10 fs + 0 hs; V 6–12 fs + 0 hs; VI 9–14 fs + 0 or 1 hs; VII 12–16 fs + 1 hs; VIII 13–15 fs + 0 hs; IX 9–11 fs + 0 hs. Segment X 66–74 μm long, with 8 or 9 fs + 3 capitate setae, each particularly long, each about 88 μm; antennal bristles not differentiated.

Thorax. Prothorax: pronotal ridge (prnr) well-developed and probably meeting medially on dorsum; lateral pronotal sclerite (prn) well developed. Pronotal setae (stn 1 s), medial pronotal setae, post-tergites and post-tergital setae absent. Sternum (stn 1) mildly sclerotised, without either a median or a transverse ridge; without reticulations, with 1 pair of prosternal setae. Anteprosternal (astn 1 s) and antemesospiracular seta (am 2 s) absent.

Mesothorax: prescutum (prsc) 132 μm wide, 202 μm long; not reticulated; prescutal ridges (pscr) and prescutal suture (pscs) well developed; with 1 small hs prescutal seta (prscs) on each side. Scutum (sct): median membranous area 130 μm wide, 21 (–41?) μm long; scutal setae (scts) absent; bounded laterally by a weak sclerotised margin; reticulations weak or absent laterad to scutellum. Scutellum (scl) 155–174 (144–156) μm wide, 31–33 (36–42) μm long; without a foramen; without scutellar setae (scls). Basisternum (stn 2) about 269 μm wide, 145 μm long; with- out a median ridge (mdr); bounded anteriorly by a weak marginal ridge (mr) and posteriorly by a strong precoxal ridge (pcr 2); without basisternal setae (stn 2 s); lateropleurite quite broad and expanded anteriorly, without an extension along anterior margin; furca (f) well developed, broad basally, arms more or less parallel and quite short. Area bounded anteriorly by scutellum and laterally and posteriorly by mesopostnotum lightly sclerotised with a narrow membranous area along anterior and lateral margins. Mesepisternum (eps 2) and subepisternal ridge (ser) well developed. Postalare (pa) not reticulated anteriorly; without postalare setae (pas). Postmesospiracular setae (pm 2 s) absent. Mesothoracic spiracle (sp 2): peritreme 29 μm wide, each with 2 disc-pores. Tegula (teg): with about 4 or 5 hs tegular setae (tegs).

Metathorax: with 1 pair of metatergal setae (mts). Dorsospiracular setae (dss) absent. Dorsal part of metapleural ridge (plr 3) absent; ventral part of metapleural ridge quite long; metepisternum (eps 3) with 6–9? hs postmetaspiracular setae (eps 3 s) on each side. Metepimeron present, without setae. Antemetaspiracular setae (am 3 s) absent. Metathoracic spiracle (sp 3) positioned posterior to mesocoxae: width of peritreme 30–32 μm; without disc-pores. Postnotal apophysis (pna) represented by a long, narrow slit between meso- (pn 2) and metapostnotum (pn 3). Metasternum (stn 3) lightly sclerotised. Anterior metasternal setae (amss) and posterior metasternal setae (pmss) absent.

Wings: very narrow, about 1.5 mm long, 0.48–0.5 mm wide (ratio of length to width 1:0.32; ratio of total body length to wing length 1:0.87); without alar lobe and alar setae. Hamulohalteres absent.

Legs: legs subequal in length; without pronounced concentric ridges. Coxae (cx): I 115–125; II 104; III 104 μm long; coxa III with a total of 9 or 10 setae; longest 66–68 μm long. Trochanter (tr) + femur (fm): I 269–274; II 281–290; III 248–253 μm long; trochanter III with 2 or 3 hs; long trochanter seta 71–80 μm long, flagellate; femur III with about 12 hs. Tibia (ti): I 327–335; II 352; III 310–323 μm; tibia III with a total of about 30 setae, mostly spur-like, particularly on distal third of leg; tibio-tarsal articulation with a small sclerotised area, but no fully-developed articulatory sclerosis; apical spur (tibs): length (III) 23–29 μm. Tarsi (ta): I 178–187; II 149–162; III 149–162 μm long (ratio of length of tibia III to tarsus III 1:0.49); tarsus III with 19–27 setae, mostly spur-like; tarsal spurs (tabs) absent or barely differentiated (26–30 μm long). Claws (c) rather elongate and narrow; without a denticle; length (III) 30–32 μm.

Abdomen: tergites (at) and sternites (as) sclerotised on all segments; pleurites (ap) sclerotised on segments III–VII. Dorsal abdominal setae (ads) (totals): segments I–VII: each with 2 hs. Pleural setae: (on each side): dorsopleural setae (dps): II & III each with 0 hs; IV 1 hs; V 4 hs; VI 7 hs; VII 7–9 hs; ventropleural setae (vps) II 0 hs; III–VII each with 1 hs. Ventral abdominal setae (avs): II 0 hs; III 2; IV–VI each with 4 hs; VII 2 hs. Caudal extensions on segment VII absent.

Segment VIII with a pair of rudimentary glandular pouches, each with 1 disc-pore and three setae: one long (66 μm long); one medium (25–28 μm long) and one short seta (10 μm long); length of sclerotised part of pouch 85 μm, width 83 μm. Small convex pores (cp) absent. Sternite strongly sclerotised and rather elongate. Caudal extension absent.

Genital segments: penial sheath (ps=segment IX + style) articulating anteriorly with sternite of segment VIII; total length 125 μm long from posterior margin of segment VIII; 43 μm wide at base of segment VIII (ratio of total body length to penial sheath length 1:0.12). Anus (an) surrounded by a sclerotised ring. Style parallel-sided anteriorly and then narrowing to a blunt apex. Basal rod (bra) short, 22 μm long anterior to aedeagus. Aedeagus (aed) short, 66 μm long (ratio of aedeagus length to basal rod length 1:0.33) and broad, approximately parallel-sided but wider than apex of style. Style with several short setae and sensilla. Membranous ‘endophallus’ absent.

Comment. Adult male A. distorta is very similar to those of the other Aclerda species discussed here, but is rather larger. The main difference between A. distorta and the other species is the presence of an incipient glandular pouch (the presence of a disc-pore suggests it could be a pouch but the presence of three setae suggests otherwise!)

Figures

FIGURE 79. Aclerda distorta Green. Macropterous male. (Aclerdidae, Aclerdinae). Where A=cranial apophysis, E=loculate pore and R=dermal reticulations on ocular sclerite.