Eriochiton armatus Brittin

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 : 48-50

Eriochiton armatus Brittin ( Fig. 17 )

Lecanium armatus Brittin 1915, 152 . Type data: New Zealand, South Island, Oamaru, on Muehlenbeckia sp., 08.07.1913, G.

Brittin. Lectotype, female, by subsequent designation ( Hodgson & Henderson 1996, 155). Type depository: NZAC. Eriochiton armatus (Brittin) ; Hodgson & Henderson 1996, 155. Change of combination.

Material examined. New Zealand ( BP), Whangaparaoa Beach Sand Dunes, on leaves and twigs of Muehlenbeckia complexa (Polygonaceae) , 13.iii.1994, R.C. Henderson ( NZAC: #94-047b/d): 2/2ad ♂♂ (g, but 1 with a rather de- formed head).

Mounted material: small, total body length 1.00– 1.03 mm; antennae a little over half total body length; body with few setae, fleshy setae (fs) possibly absent on body, but quite easy to separate from hs on antennae; length of fs on antennae shorter than width of antennal segments. Wings about 0.9 times total body length and about 0.45 times as wide as long.

Head: approximately oval in dorsal view; width across genae about 200 μm. Median crest (mc) poorly demarcated and not reticulated; preocular ridge (por) distinct, with pairs of short posterior and anterior ridges; with (on each side) 6 or 7 hs dorsal head setae (dhs) + 3 or 4 simple (non-loculate) pores. Mid-cranial ridge: dorsal ridge (dmcr) well developed but narrow, extending posteriorly to about level with dorsal simple eyes; ventral ridge (vmcr) well developed, extending from lateral arms (lmcr) posteriorly about half-way to postoccipital sclerite; without reticulations laterally; with 3 hs ventral mid-cranial ridge setae (vmcrs) on either side of ridge and 4 rather longer hs setae anterior to preocular ridge. Postoccipital ridge (por) well developed with short anterior and posterior lateral arms. Genae (g) not reticulated but with 1 or 2 hs genal setae (gs) on each side laterad to postoccipital ridge. Eyes: with two pairs of round simple eyes, subequal in size, each 30–34 μm wide; ventral eyes quite far forward but clearly posterior to dorsal eyes. Ocelli (o) quite large, very convex and placed laterally, 15–17 μm wide; just touching postocular ridge (pocr) posteriorly. Ocular scler- ite (ocs) sclerotised but only reticulated immediately around each simple eye; each reticulation without inner ridges. Preocular ridge (procr) quite long, extending posteriorly to immediately above each ventral simple eye and dorsally to above each dorsal simple eye. Postocular ridge (pocr) strongly developed, extending dorsally past posterior margin of each dorsal eye almost reaching postoccipital ridge (por) medially. Dorsal ocular setae absent. Ventral head setae absent. Preoral ridge (pror) poorly developed. Cranial apophysis (ca) possibly quite short and rounded; length 40 μm.

Antennae: 10-segmented and filiform; 540–600 μm long (ratio of total body length to antennal length 1:0.57). Scape (scp): 41–47 μm long, 50 μm wide, with 3 hs ventrally and 1 dorsally. Pedicel (pdc): length 58–66 μm, width 38–42 μm; with slight concentric ridging distally; with 0 or 1 fs, 12–14 hs + 1 campaniform pore. Segments III–X all 26–32 μm wide: fs 23–25 μm long; lengths of segments (μm): III 102–115; IV 69–78; V 65: VI 56–58; VII 48–53; VIII 46–52 and IX 44–47; approximate number of setae per segment: III 7 or 8 fs + 12–14 hs; IV 10–12 fs + 5–8 hs; V 8–12 fs, 3–5 hs + 1–3 capitate setae (caps); VI 7–8 fs, 1–4 hs + 4–6 caps; VII 5–10 fs, 2 or 3 hs + 4 or 5 caps; VIII 7 or 8 fs, 1 or 2 hs, 1 bristle + 5 caps; IX 3–6 fs, 2 hs, 1 bristle + 3–7 caps (hs tending to be distal on more apical segments). Segment X oval, length 50 μm; not constricted apically; with 6–9 caps, 3–6 fs + 5 bristles; sensilla basiconica (sb) not detected.

Thorax. Prothorax: pronotal ridge (prnr) well-developed and perhaps fused dorsally; with a small, slightly striated, triangular, lateral pronotal sclerite (prn), without lateral pronotal setae. Medial pronotal and post-tergital setae apparently absent. Post-tergites not detected. Sternum (stn 1) not sclerotised but with radial striations; with a fairly weak transverse ridge; median ridge short and very weak; without prosternal setae. Anteprosternal setae absent. Antemesospiracular setae (am 2 s): with 0 or 1 hs just posterior to each procoxa.

Mesothorax: prescutum (prsc) transversely oval, 58–73 μm long, 153 μm wide; sclerotised but not reticulated; prescutal ridges (pscr) well developed; prescutal suture (pscs) poorly developed. Scutum (sct): median area sclerotised but not reticulated, 26–30 μm long, with 0 or 1 hs on each side near prescutum; lateral scutal setae (scts): 1 pair laterad to median area; lateral margins sclerotised but not reticulated; prealare ridge (prar) weak. Scutellum (scl) 138–145 μm wide, 53–60 μm long; with an inverted U-shaped scutellar ridge (sclr); not tubular but with a large foramen; scutellar setae (scls): 1 pair hs; posterior notal wing process (pnp) quite long and heavily sclerotised. Basisternum (stn 2) 198–203 μm wide, 103 μm long; without any signs of a median ridge (mdr), but bounded anteriorly by a moderately strong marginal ridge (mr) and posteriorly by strong precoxal ridges (pcr 2); without basisternal setae; lateropleurite (lpl) triangular and well developed, with a long extension along anterior margin from marginal ridge; furca (f) well developed, narrow-waisted, arms very divergent and extending almost to anterior marginal ridge. Mesopostnotum (pn 2) well developed; postnotal apophysis (pna) well developed and quite long. Area bounded anteriorly by scutellum and laterally and posteriorly by mesopostnotum not sclerotised. Mesepisternum (eps 2) not reticulated; subepisternal ridge (ser) well developed. Postalare (pa) well developed; without postalare setae. Mesothoracic spiracle (sp 2) small: width of peritreme 20 μm. Postmesospiracular setae absent. Tegula (teg) present, with 2 quite long hs tegular setae (tegs) on each side.

Metathorax: with 1 pair of hs metatergal setae (mts) medially. Dorsospiracular setae (dss): 1 hs + 2 loculate pores on each side. Dorsal part of metapleural ridge (plr 3) well developed; suspensorial sclerite (ss) present. Posterior part of metapleural ridge well developed; episternum (eps 3) slightly sclerotised, without postmetaspiracular setae; precoxal ridge (pcr 3) arising between coxae and extending a long way medially. Metepimeron (epm 3) sclerotised, but without setae. Antemetaspiracular setae absent. Metathoracic spiracle (sp 3) small: width of peritreme 20–25 μm. Metasternum (stn 3) membranous, with 1 pair of hs anterior metasternal setae (amss) and 0 or 1 pair of hs posterior metasternal setae (pmss).

Wings: hyaline, possibly 825–925 μm long, 400–410 μm wide (ratio of length to width 1:0.46; ratio of total body length to wing length 1:0.86); alar lobe (al) well developed; alar setae (als): 2 quite long hs on each wing. Hamulohalteres 83–90 μm long, 20–27 μm wide; with a single hooked seta, 58–65 μm long.

Legs: legs subequal in length. Coxae (cx): I 78–91; II 83–91; III 91–94 μm long; setae of coxa III: 9–12 hs; long apical setae on each coxa 50–66 μm long. Trochanter (tr) + femur (fm): I 198–212; II 173–190; III 178–199 μm long; trochanter III with 5–8 hs; long trochanter seta up to 30–45 μm; femur III with 15–18 hs. Tibia (ti): I 193–203; II 182–203; III 186–229 μm; tibia III with a total of 42–48 setae, mainly hs, a few becoming spur-like on distal third of leg, and with 1–3 fs on dorsal surface distally; with 2 apical spurs (tibs), length 16–23 μm. Tarsi (ta): I 74–79; II 79; III 80–83 μm long (ratio of length of tibia III to length of tarsus III length 1:0.40); tarsus III with 28–31 setae, mainly spur-like, but with 0–5 fs on proximal end dorsally; tarsal spurs barely differentiated, each 25 μm long; tarsal campaniform pore present; tarsal digitules (tdt) subequal to or slightly longer than claw, with small apical knobs. Claws (c) quite long and thin, subequal to or slightly shorter than width of tarsi, almost straight, with a distinct denticle; length: III 24–29 μm; claw digitules (cdt) slightly longer than claw, with minute apical knobs.

Abdomen: segments I–VII: tergites (at) distinctly sclerotised on posterior segments, becoming less so anteriorly with segments I & II unsclerotised; sternites (as) unsclerotised except VII sclerotised and VI slightly sclerotised; without obvious oval membranous areas in inter-segmental membranes. Caudal extensions (ce) on segment VII absent. Dorsal setae (ads): segment I 1 or 2; II–VII each with 4 hs. Pleural setae: dorsopleural setae (dps): segments II–VI each with 2–4 hs; VII 5 hs; ventropleural setae (vps) (on each side): II–VI each with 1 hs. Ventral setae (avs) (totals): II–VI each with 2–4 hs; VII 6 hs.

Segment VIII: tergite (at) and sternite (as) sclerotised; tergite with 2 hs ante-anal setae (aas); sternite with about 2 hs ventral abdominal setae (avs); caudal extension (ce) rounded, with 3 hs pleural setae, one a little longer than rest (about 35 μm long). Glandular pouches (gp) present, shallow, each with a few loculate pores outside pouch; glandular pouch setae (gts) each 60–68 μm long.

Genital segments: penial sheath (ps): segment IX broad and sclerotised (78–97 μm wide, 95 μm long) with anal opening medially on dorsal surface; with two longish setae lateroventrally on posterior margin, each 38–50 μm long. Style quite broad anteriorly (43–46 μm wide) but then gradually tapering to a point; sclerotised; length from base of segment IX 103–108 μm (ratio of total body length to length of penial sheath + segment IX 1:0.19); with 2 pairs of long setae about half way along style, each a bit shorter than those anteriorly, each 38–45 μm long. Aedeagus more or less parallel-sided, tapering near apex, 12–14 μm wide at base; length 99–103 μm. Basal rod (bra) short and tapering anteriorly, 17–25 μm long anterior to internal genital aperture (iga). Penial sheath with a few small sensilla near apex and on margin of posterior third.

Comment. The adult male of E. armatus is very similar to that of E. hoheriae Hodgson ( Hodgson & Henderson 1996) , except that the former species has 2 pairs of loculate pores dorsally on the metathorax.

Figures

FIGURE 17. Eriochiton armatus Brittin. Macropterous male. (Eriococcidae, Acanthococcid group). Where A=cranial apophysis and C=loculate pore.