Lachnodius, Maskell, 1896

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 : 89-91

Lachnodius ? eucalypti (Maskell) ( Fig. 34 )

Dactylopius eucalypti Maskell 1892, 35 . Type data: Australia, South Australia, on Eucalyptus amygdalina , by Crawford. Lectotype, female. Type depository: ANIC.

Lachnodius eucalypti (Maskell) ; Maskell 1896, 400.

Material examined. South Australia, Sampson Flats, on Eucalyptus camaldulensis (Myrtaceae) , 9.vii.1965, D.C. Purde ( BMNH): 1/1ad ♂ (in fair condition, cover-slip cracked across abdomen of specimen and therefore setae hard to see; one antenna missing).

Mounted material: quite large, total body length about 2.15 mm; antennae rather short; body with few setae; fleshy setae (fs) few and hard to separate from hs; length of fs on antennae rather longer than width of antennal segments. Wings about 0.9 total body length and about 0.4 as wide as long.

Head: appearing rather five-sided in dorsal view, with anterior part elongated and pronounced and probably with a distinct postero-ventral bulge with ventral eyes; width across genae about 360 μm. Median crest (mc) poorly demarcated and not striated or reticulated. Postoccipital ridge (por) distinct, with a pair of long posterior ridges; anterior ridges short; with (on each side) about 10 hs dorsal head setae (dhs) + a group of irregular-shaped pores (number unclear). Mid-cranial ridge: dorsal ridge (dmcr) well developed but narrow, extending onto ventral surface; ventral ridge (vmcr) broad and pronounced, extending from lateral arms (lmcr) posteriorly to postoccipital sclerite; without any reticulations laterally; with 2 hs ventral mid-cranial ridge setae (vmcrs). Genae (g) not reticulated and without genal setae (gs). Eyes: with two pairs of round simple eyes; dorsal eyes (dse) placed well forward, each dorsad to an antennal scape, possibly slightly larger than ventral eyes (vse); dorsal eyes each possibly 75 μm wide, ventral eyes each 60 μm wide. Ocelli (o) quite large, 36 μm wide, each placed well dorsad to postocular ridge (pocr). Ocular sclerite (ocs) sclerotised and polygonally reticulated at least around ventral eyes, each reticulation quite large, without inner microridges. Preocular ridge (procr) short, extending dorsally from outer margin of each scape, probably almost to each dorsal 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 (vhs): at least 20 on each side anterior and laterad to each ventral eye; also with at a median group of about 12 just anterior to mouth and about 3 hs on each side posterior to ventral eyes. Preoral ridge (pror) poorly developed. Cranial apophysis (ca) quite short and bifid; length 58 μm.

Antennae: 10-segmented and filiform; 933 μm long (ratio of total body length to antennal length 1:0.43). Scape (scp): 59–64 μm long, 58–61 μm wide, with 1 fs + 3 hs. Pedicel (pdc): length 66–75 μm, width 54–58 μm; with a few concentric ridges and 0 or 1 fs + 1–3 hs. Segments III–X all 25–33 μm wide: fs 33–35 μm long; lengths of segments (μm): III 159; IV 108; V 91, partially fused with VI 141; VII 100; VIII 91 and IX 114; approximate number of setae per segment (note: fs and hs hard to differentiate): III 4 fs + 1 sensilla basiconica; IV 14 fs; V 13 fs; VI 20 fs; VII 21 fs; VIII 21 fs + 1 bristle; IX 33 fs + 3 bristles. Segment X oval, length 51 μm; not constricted apically; with 4 (5?) capitate setae (caps), 7 fs, 3 large + 1 small bristle (ab); sensilla basiconica (sb) not detected.

Thorax. Prothorax: pronotal ridge (prnr) well-developed but not fused dorsally; with a well-developed, striated, lateral pronotal sclerite (prn), without lateral pronotal (lpns) setae. Medial pronotal and post-tergital setae apparently absent. Post-tergites not detected. Sternum (stn 1) not sclerotised but with radial striations; with a quite strong transverse ridge; median ridge absent; with 2–4 hs prosternal setae (stn 1 s) on each side. Anteprosternal and antemesospiracular setae absent.

Mesothorax: prescutum (prsc) elongate oval, 251 μm long; 202 μm wide; sclerotised and nodulated; prescutal ridges (pscr) well developed; prescutal suture (pscs) less well developed. Scutum (sct): median area sclerotised and lightly nodulated, about 100 μm long, with a few small hs (perhaps 5 on each side); scutal setae (scts) absent later- ally; lateral margins sclerotised and lightly striated; prealare ridge (prar) quite well developed. Scutellum (scl) 298 μm wide, 83 μm long; with an inverted U-shaped scutellar ridge (sclr) and a large foramen; scutellar setae absent. Basisternum (stn 2) 447 μm wide, 290 μm long; without a median ridge (mdr), but bounded anteriorly by a strong mar- ginal ridge (mr) and posteriorly by strong precoxal ridges (pcr 2); with 33+ hs basisternal setae (stn 2 s); also with some striations on each side; lateropleurite (lpl) rather narrow, with a short 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) small or absent. Area bounded anteriorly by scutellum and laterally and posteriorly by mesopostnotum not sclerotised. Mesepisternum (eps 2) not reticulated; subepisternal ridge (ser) long and well developed. Postalare (pa) with radial ridges dorsally near posterior notal wing process; without postalare setae. Mesothoracic spiracle (sp 2) large: width of peritreme 50 μm. Postmesospiracular setae (pm 2 s): 2 or 3 hs posterior to each spiracle. Tegula (teg) present, with 5 or 6 hs tegular setae (tegs) on each side.

Metathorax: with a single pair of metatergal setae (mts). Dorsospiracular setae absent. Dorsal part of metapleural ridge (plr 3) absent, ventral part of metapleural ridge well developed; episternum (eps 3) sclerotised, with perhaps 2 or 3 hs postmetaspiracular setae (eps 3 s) on either side. Metepimeron (epm 3) sclerotised, but without setae. Antemetaspi- racular setae absent. Metathoracic spiracle (sp 3) large: width of peritreme 53 μm. Metasternum (stn 3) membranous, with a pair of hs anterior metasternal setae (amss); posterior metasternal setae (pmss) absent.

Wings: hyaline, possibly 1900–2000 μm long, 825–875 μm wide (ratio of length to width 1:0.44; ratio of total body length to wing length 1:0.91); alar lobe, alar sensoria and alar setae absent. Hamulohalteres absent.

Legs: prothoracic legs possibly marginally longest. Coxae (cx): I 146; II 133–140; III 146 μm long; setae of coxa III each with about 12 fs + 5 hs; long apical setae on each coxa 41–50 μm long. Trochanter (tr) + femur (fm): I 355–370; II 361–366; III 356 μm long; trochanter III with about 0 fs + 4 or 5 hs; long trochanter seta up to 83–97 μm; femur III with 47–56 setae (mostly hs); sensoria on each trochanter arranged in a straight line. Tibia (ti): I 285–305; II 273–286; III 285–292 μm; tibia III with a total of 30–40 setae, mainly hs, a few becoming spur-like on distal third of leg; with 2 apical spurs (tibs), length 21–25 μm. Tarsi (ta): I 83; II 82–86; III 88–96 μm long (ratio of length of tibia III to length of tarsus III 1:0.32); tarsus III with 6–8 setae, mainly spur-like; tarsal spurs barely differentiated, each 20 μm long; tarsal campaniform pore present; tarsal digitules (tdt) capitate, subequal to or slightly longer than claw. Claws (c) quite long and thin, subequal to or slightly longer than width of tarsi, slightly curved, perhaps with a small denticle; length: III 30 μm; claw digitules (cdt) slightly longer than claw.

Abdomen: segments I–VII: tergites (at) and sternites (as) lightly sclerotised. Caudal extension of segment VII absent. Dorsal setae (ads) (totals): segments I–VI each probably with 2–6 hs; VII about 12 hs. Pleural setae: dorsopleural setae (dps) + ventropleural setae (vps) (on each side): III 1 moderately long hs + 4 small hs; IV–VI each with 1 or 2 long hs + 6–9 short hs; VII 4 large hs + 10–18 short hs. Ventral setae (avs) (totals): II–VII each with 10–14 setae.

Segment VIII: tergite (at) and sternite (as) possibly sclerotised; tergite with about 14 hs dorsal abdominal setae; sternite with about 8 ventral abdominal setae (avs); caudal extension absent but with 1 extra long hs (74–83 μm), 4 or 5 long hs + about 3 or 4 short hs pleural setae. Glandular pouches (gp) present, deep, each facing towards penial sheath; glandular pouch setae each about 83 μm long but almost certainly all broken.

Genital segments: Abdominal segment IX sclerotised and broad (194 μm wide, 83 μm long); anal opening prob- ably present medially on posterior border; with two longish setae laterally on posterior margin, plus about 12 short setae on ventral surface and 12 on dorsal surface, mainly anterior to anus. Style quite broad anteriorly (108 μm wide) but then abruptly tapering to a point; sclerotised; length of penial sheath from base of segment IX 161 μm (ratio of total body length to length of style + segment IX 1:0.11); style with four pairs of setae at point where style narrows, those laterally each 53–65 μm long. Aedeagus bottle-shaped, 58 μm wide at base, narrowing to a parallel-sided posterior half, with a blunt apex; length about 150 μm; with a darker structure within broad base, possibly a basal rod (bra). Style with a few small sensilla near apex.

Comment. Adult male L. eucalypti belong to the group of Gondwanan eriococcids that have glandular pouches and 10-segmented antennae. For main differences from other species, see key above but, in addition, the aedeagus is unusual in being bottle-shaped in dorsal view, only otherwise known in the neotropical Stibococcus cerinus , which is morphologically fairly similar.

Figures

FIGURE 34. Lachnodius?eucalypti (Maskell). Macropterous male. (Eriococcidae, Gondwanan group). Where A=cranial apophysis.