Dactylopius coccus (Costa)

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 : 68-72

Dactylopius coccus (Costa) ( Fig. 24 )

Dactylopius coccus Costa 1829, 16 . Type data: Italy, on Opuntia “Fico d’India”. Type status unknown, Type depository: HNHB.

Coccus cacti (Costa) ; Signoret 1875b, 347. Type depositories: BMNH; MNHN.

Coccus cacti domestica Meunier 1884, 19 . Junior synonym, Lindinger, 1935, 133.

Coccus cacti (Costa) ; Cockerell 1893b, 1041. Type depositories: Department of Entomology, ICV; MNHN.

Dactylopius coccus (Costa) ; Cockerell 1902c, 454. Subsequent use.

Material examined. Spain, Canary Is., Gran Canaria, Bco de Azuaje, W. of Firgas, on Opuntia sp., 6.xii.2002, J. Martin 7737 ( BMNH): 2/2ad ♂♂ (1 specimen in good condition, other with poorly expanded wings).

Mounted material: of moderate size, total body length 2.0– 2.2 mm; antennae fairly short, about half total body length; flagellate segments with short, stout fleshy setae (fs), and most segments with long capitate setae (caps); body with few setae, all hs, fs apparently absent. Wings subequal to total body length, width less than half length.

Head: rather pointed anteriorly, with ventral eyes approximately level with dorsal simple eyes; probably with ventral simple eyes on a distinct postero-ventral bulge; head length about 290 μm; width across genae 320–330 μm. Median crest (mc) not reticulated but distinct and long, extending posteriorly to well past posterior margin of ocular sclerite. Postoccipital ridge (por) absent; with (on each side) 10–15 hs dorsal head setae (dhs), extending full length of median crest; pores absent. Mid-cranial ridge: dorsal (dmcr), ventral (vmcr) and lateral ridges all absent; median crest ventrally with with 3 or 4 ventral mid-cranial ridge setae (vmcrs) on each side. Genae (g) not reticulated; with 3 or 4 hs genal setae (gs) on each side just posterior to ocular sclerites. Eyes: with two pairs of round simple eyes; dorsal eyes (dse) slightly larger than ventral eyes (vse), latter placed well forward, each probably approximately level with dse; dse each 30–33 μm wide, vse each 25 μm wide. Ocelli (o) pronounced, situated laterally, each 33–35 μm wide, close to dorsal end of postocular ridge (pocr). Ocular sclerite (ocs) sclerotised but apparently not striated or reticulated, even around each simple eye. Preocular ridge (procr) poorly developed, only visible ventrally for a short distance from each scape, before joining “interocular ridge”. Postocular ridge (pocr) strongly developed posteriorly but fading laterally near ocelli and faint or absent along dorsal margin of ocular sclerite. “Interocular ridge (ioc)” distinct anteriorly and posteriorly but only faint in between, extending from posterior end of postocular ridge anteriorly across ocular sclerite, fusing anteriorly with ventral end of preocular ridge, and then appearing to extend ventrally to fuse with posterior end of median crest. Dorsal ocular setae and ventral head setae absent. Preoral ridge (pror) well developed. Cranial apophysis (ca) present but shape unknown.

Antennae: 10-segmented, each flagellar segment rather club-shaped; each antenna 1100–1175 μm long (ratio of total body length to antennal length 1:0.57). Scape (scp) wider than long: 62–75 μm long, 83 μm wide, with 3 hs dor- sally and 1 hs ventrally. Pedicel (pdc): length 95–100 μm, width 60–65 μm; with concentric ridges on distal end; with 4–7 hs + a campaniform pore. Segments III–X all much broader distally where each 50–58 μm wide; lengths of seg- ments (μm): III 155–160; IV 128–158; V 115–140; VI 105–125; VII 100–115; VIII 95–108 and IX 100–105; fs each 10–14 long, 3 μm wide; approximate number of setae per segment: III 13–27 fs + 10 or 11 hs; IV 28 fs, 6 or 7 hs + 1 caps; V 22–29, 3–5 hs + 2 or 3 caps; VI 19–27 fs, 1 or 2 hs + 3 or 4 caps; VII 19–25 fs, 2 hs + 4 caps; VIII: 16–19 fs, 0 hs, 4 or 5 caps + 1 antennal bristle near anterior end (similar to fs but longer); IX: 10 fs, 0 hs, 5 caps + 1 bristle near anterior end. Segment X not constricted apically: length 105–110 μm; with 4 caps, 6 or 7 fs, 3 large bristles + 2 small bristles on apical third; with 2 sensilla basiconica (sb) on distal 1/3rd.

Thorax. Prothorax: pronotal ridge (prnr) well-developed but not fused medially on dorsum; pronotal sclerite (prn) extending laterally, without lateral pronotal setae (lpns). Sternum (stn 1) lightly sclerotised; median ridge absent; transverse ridge well sclerotised. Proepisternum + cervical sclerites well developed and broad posteriorly.All setae and pores absent.

Mesothorax: prescutum (prsc) oval, 175 μm long, 230–260 μm wide; sclerotised but not reticulated; prescutal ridge (pscr) well developed anteriorly but fading posteriorly; prescutal suture (pscs) poorly developed; with 1 or 2 pairs of hs prescutal setae (prscs). Scutum (sct): median area sclerotised, not reticulated, 62 μm long; scutal setae (scts): with about 6 or 7 hs on each side; lateral margins sclerotised but not reticulated; without a distinct sclerotised invagination on anterior margin near prealare; prealare ridge (pra) well developed. Scutellum (scl) 220–235 μm wide, 115–130 μm long; without a scutellar ridge (sclr) but with a large foramen; scutellar setae (scls): 2 or 3 hs on each side, of which 1 generally rather long; postnotal wing process (pnp) quite broad. Basisternum (stn 2) 570 μm wide, 175 μm long; without a median ridge; bounded anteriorly by a strong marginal ridge (mr) and posteriorly by strong precoxal ridges (pcr 2); without basisternal setae; lateropleurite (lpl) broad, with an extension from marginal ridge along anterior margin and with 2 setae along margin with basisternum; furca (f) particularly well developed, quite broadly waisted, arms very divergent and extending to (or past) marginal ridge anteriorly. Mesopostnotum (pn 2) well developed; postnotal apophysis (pna) well developed. Area bounded anteriorly by scutellum and laterally and posteriorly by mesopostnotum membranous. Mesepisternum (eps 2) not reticulated; subepisternal ridge (ser) long and well developed. Postalare (pa) without reticulations and without postalare setae. Mesothoracic spiracle (sp 2): width of peritreme about 45 μm, without associ- ated loculate pores. Postmesospiracular setae (pm 2 s): 3 or 4 hs posterior to each spiracle. Tegula (teg) present, with 5–7 tegular setae (tegs).

Metathorax: with 5–8 hs metatergal setae (mts) on each side, well spaced, and with 2 dorsospiracular setae on each side; metapostnotal sclerite (pn 3) indistinct or absent. Dorsal part of metapleural ridge (plr 3) absent; ventral part of plr 3 well developed; episternum (eps 3) only lightly sclerotised, without postmetaspiracular setae; precoxal ridge (pcr 3) poorly developed; metasternal apophyses (sta) distinct but shallow. Metepimeron (epm 3) sclerotised and quite long, but without setae. Antemetaspiracular setae absent. Metathoracic spiracle (sp 3): width of peritreme 20–23 μm, with- out loculate pores. Metasternum (stn 3) membranous, without anterior metasternal setae (amss) but with 2–4 posterior metasternal setae (pmss) on each side.

Wings: hyaline, about 2075 μm long, 875 μm wide (ratio of length to width 1:0.42; ratio of total body length to wing length 1:1.03); alar lobe (al) poorly developed; alar setae (als) and sensoria (sens) absent; microtrichia noticeably sparse. Hamulohalteres (h) absent.

Legs: subequal in length. Coxae (cx) (lengths in μm): I 165–170; II 190; III 178–185; setae of coxa III: about 5 hs; long setae on each coxa not differentiated. Trochanter (tr) + femur (fm): I 365–400; II 360–390; III 375–395 long; trochanter III with about 4 hs; each trochanter with 3 circular sensoria arranged in a triangle; long trochanter seta 55–65 µm long; femur III with about 17 hs. Tibia (ti): I 185–205; II 295–305; III 310–325; tibia III with 5–9 hs + 6–11 small spur-like setae; with 2 apical spurs (tibs) on each tibia. Tarsi (ta) 2 segmented; lengths I 185–205; II 170–190; III 180– 190 (ratio of length of tibia III to length of tarsus III 1:0.59); tarsus III with hs + 8–12 small spur-like setae; tarsal spurs not differentiated; tarsal campaniform pore present; tarsal digitules (tdt) subequal to length of claw with small capitate apices. Claws (c) long and thin, nearly twice width of tarsus, almost straight, without a denticle; length: III: 41–44 μm; claw digitules (cdt) subequal to length of claw, with small capitate apices.

Abdomen: segments I–VII: tergites (at) and sternites (as) unsclerotised except for narrow sclerotisations dorsally on anterior margins of segments I and II. Caudal extension (ce) on segment VII absent. Without loculate pores. Dorsal setae (ads): segments I–VII 3–7 hs on each side. Pleural setae: dorsopleural setae (dps) on each side: I with 1 hs; II–VII each with 2 hs; ventropleural setae (vps) (on each side): I–VII each with 1 hs. Ventral setae (avs) (on each side): II 2; III–VII each with 5 hs. Ostioles absent.

Segment VIII: tergite (at) lightly sclerotised medially, with 2–4 ante-anal setae (aas) on each side; sternite (as) with a small sclerotisation anterolaterally and with 2 pairs of hs ventral abdominal setae (avs); caudal extension (ce) rounded, with about 5 or 6 hs pleural setae. Glandular pouches (gp) present, apparently quite deep, each with a compact group of 4-locular pores; each pouch with 2 very short, truncated glandular pouch setae (gls), each 40–75 μm long.

Genital segments: penial sheath (ps) short, narrowly triangular and blunt; 270–295 μm long, 185 μm widest. Seg- ment IX with anal opening large, about 50 μm wide, with a group of 4–6 setae medially, each 16–30 μm long; style with ventral surface rather membranous antero-medially, with 7–14 short setae on each side at anterior end, each 10–12 μm long. Basal ridge (brps) well developed. Aedeagus parallel-sided, extending almost to end of style, 100 μm long, about 25 μm wide at apex. Basal rod distinct, about 85 μm long to anterior end of aedeagus, extending posteriorly to about half-way to anterior margin of basal ridge. Posterior margins of style with 4–6 very short setae (psp) on each side and a few sensilla (psp) on apex.

Comment. The above description is similar to that of Pérez Guerra and Kosztarab (1992) as far as the latter goes. However, their specimens were apparently up to 3.5 mm long and 1.5 mm wide across the thorax (huge by the standards of most neococcoids). Indeed, all their measurements seem to be 2 or more times greater than those above. They also illustrate a strong postocular ridge on the dorsal surface of the head; a seta on the ocular sclerite; antemesospiracular setae as present and setae on the membranous area posterior to the scutellum. None of these characters were noted on either the above specimens of D. coccus nor on the two species studied by Loubser (1966) nor on the specimens of D. tomentosus discussed below.

The adult male of D. tomentosus ( de Lamarck 1801) is also illustrated ( Fig. 25 ) [ USA, Southern California, on Opuntia echinocarpa , 1.x.1924, A.P. Dodd (USNM)]. The adult male of D. tomentosus differs from that of D. coccus in having: (i) an interrupted interocular ridge; (ii) many fewer hs on each antennal segment and few capitate setae; (iii) nodulations apparent on prescutum and scutum; (iv) more scutal setae; (v) alar setae present, and (vi) fewer setae across each abdominal segment, both dorsally and ventrally. It also had a loculate structure on the head associated with the dorsal mid-cranial ridge although its homologies are uncertain.

Figures

FIGURE 24. Dactylopius coccus (Costa). Macropterous male. (Dactylopiidae). Where P=spur-like seta and T=microtrichia.

FIGURE 25. Dactylopius tomentosus (Lamark). Macropterous male. (Dactylopiidae). Where A=cranial apophysis, D=fleshy seta and X=pore-like structure on head.