Atrococcus groenlandensis, Gertsson & Hodgson

Hodgson, Chris, 2005, The adult males of Coccoidea (Hemiptera: Sternorrhyncha) known from Greenland, Zootaxa 907, pp. 1-48 : 4-9

ATROCOCCUS GROENLANDENSIS Gertsson & Hodgson (Fig. 1)

Atrococcus groenlandensis Gertsson & Hodgson, 2005: 3 .

(Described from 5 specimens, mostly in moderately good condition, with some characters checked on remaining specimens).

Live appearance: not recorded.

Mounted material: small, total body length about 0.80–1.04 mm; antennae slightly more than half total body length, with short, stout fleshy setae (fs); length of fs on antennae about equal to width of antennal segments; body with few setae, all hair­like (hs) but fs apparently absent; loculate pores (lp) each with mainly 3 to 5 loculi and each 5–7µm wide; many with a nearby minute pore. Wings shorter than total body length, about 0.9x total body length and about 0.36x as wide as long. Abdomen with 1 pair of glandular pouches.

FIGURE 1. Adult male of Atrococcus groenlandensis Gertsson & Hodgson. Where G = multilocular disc pores; H = minute pore; J = apical antennae segment; K = latero­ventral view of genital segment, and L = tarsi plus claw. And where aed = aedeagus; al = alar lobe; an = anus; as = abdominal sternite; at = abdominal tergite; bra = basal rod of aedeagus; c = claw; ce = caudal extension; cx = coxa; dmcr = dorsal mid­cranial ridge; dse = dorsal simple eye; epm3 = metepimeron; eps2 = mesepimeron; eps3 = metepisternum; f = furca; fm = femur; g = gena; gp = glandular pouch; h = hamulohaltere; ham = hamulus; iga = internal genital aperture; ior = inter­ocular ridge; lmcr = lateral arm of mid­cranial ridge; lpl = lateropleurite; mr = marginal ridge; o = ocellus; ocs = ocular sclerite; os = ostiole; pa = postalare; pcr2 = precoxal ridge of mesothorax; pcr3 = precoxal ridge of metathorax; pdc = pedicel; pepcv = proepisternum + cervical sclerite; plr3 = metapleural ridge; pn2 = mesopostnotum; pn3 = metapostnotum; pna = mesopostnotal apophysis; pnp = posterior notal wing process; pocr = post ocular ridge; por = post occipital ridge; pra = prealare; praa = apodeme on prealare; prar = prealar ridge; prn = lateral pronotal sclerite; prnr = pronotal ridge; procr = preocular ridge; pror = preoral ridge; prsc = prescutum; ps = penial sheath; pscr = prescutal ridge; pscs = prescutal suture; pt = post­tergite; scl = scutellum; scp = scape; sct = scutum; ser = subepisternal ridge; sp2 = mesothoracic spiracle; sp3 = metathoracic spiracle; ss = suspensorial sclerite; stn1 + prosternum; stn2 = basisternum; stn3 = metasternum; stn3a = metasternal apophysis; ta1 = 1st tarsal segment; ta2 = 2nd tarsal segment; teg = tegular; ti = tibia; tr = trochanter; vmcr = ventral mid­cranial ridge, and vse = ventral simple eye. For most abbreviations for setae, pores and veins, see Fig. 3.

Head: bluntly triangular, apex of triangle pointing anteriorly; probably with ventral simple eyes (vse) on a distinct postero­ventral bulge; length about 115–150µm; width across genae about 153–200µm. Median crest (mc) absent; postoccipital ridge (por) represented by a thin U­shaped ridge at posterior end of dorsal midcranial ridge (dmcr); with (on each side) about 7–12 hs dorsal head setae (dhs) + 0 or 1 (usually 0) lp mesad to each scape. Mid­cranial ridge: dorsal ridge (dmcr) distinct, long and narrow, extending posteriorly well past posterior margin of dorsal simple eyes (dse) and fusing with post­occipital ridge (por); ventral midcranial ridge (vmcr) short and narrow, well defined, extending from lateral arms (lmcr) posteriorly to anterior margin of ocular sclerite (ocs); without reticulations laterally; with 2 or 3 hs ventral midcranial ridge setae (vmcrs). Genae (g) not reticulated; with 2–4 (usually 3) hs genal setae (gs) on each side. Eyes: two pairs of round, simple eyes, subequal in size; dorsal eyes (dse) each approximately level with ventral simple eyes (vse); dorsal eyes, each 23–25µm wide, ventral eyes each 20–25µm wide. Ocelli (o) fairly pronounced, situated laterally, each 11–15µm wide, lying just dorsad to where interocular ridge (ior) and postocular ridge (pocr) meet. Ocular sclerite (ocs) lightly sclerotised, with reticulations restricted to immediately around simple eyes. Preocular ridge (procr) well developed, on dorsal surface extending from just anterior to inner margin of dorsal simple eyes antero­laterally to base of each scape (with which it articulates) and then ventrally to form interocular ridge (ior). Postocular ridge (pocr) strongly developed, extending antero­laterally, ending posterior to inner margin of dse; each fusing with ior just ventral to each ocellus. Dorsal ocular setae (docs) absent. Ventral head setae (vhs): with 4–7 hs ventral head setae (vhs) transversely on each side anterior to each vse and with 2 or 3 between eyes. Preoral ridge (pror) probably absent or poorly developed. Cranial apophysis (ca) possibly represented by a narrow finger­like extension.

Antennae: 10 segmented and filiform; 520–625µm long (ratio of total body length to antennal length 1:0.61). Scape (scp) approximately square, with pedicel arising anterolaterally: 33–42µm long and 33–45µm wide, with 2 hs ventrally and 2 hs dorsolaterally. Pedicel (pdc): length 43–56µm, width 30–35µm; with concentric ridges on distal end; with 11–18 fs, 5–9 hs; campaniform pore not detected. Segments III–X each about 20–25µm wide; lengths of segments (µm): III: 58–80; IV: 50–72; V: 50–58; VI: 50–70; VII: 56–66; VIII: 58–71; IX: 54–70; fs about 23–27µm long; approximate number of setae per segment: III: 7–12 fs + 5–7 hs (note that some hs on more basal flagellar segments probably capitate setae but shorter and without capitate apices); IV: 9–15 fs + 1–5 hs; V: 8–12 + 2 hs; VI: 11–17 fs + 3 or 4 hs; VII: 9 or 10 fs + 5 or 6 hs; VIII: 8–12 fs, 4–7 hs + 1 bristle (abr) (about half­way along segment); IX: 9–12 fs, 4 or 5 hs + 1 bristle (abr) (about halfway along segment). Segment X with a slightly constricted apex: length 63–70µm; with 6 or 7 long setae, mainly capitate (caps), about 8–10 fs, 1 hs + 3 bristles (abr) near apex (these clearly differentiated from fs); with 1 or 2 sensilla basiconica (sb) near apex.

Thorax. Prothorax: pronotal ridges (prnr) well developed but not fused dorsally; long, extending ventrally and nearly touching proepisternum + cervical sclerite (pepcv); pronotal sclerite (prn) represented by a small finger­like area extending postero­laterally; without lateral pronotal setae (lpns). Medial pronotal setae (mpns): 0–3 hs + 0–2 lp on each side; post­tergite (pt) possibly present, with 0 or 1 post­tergital setae (pts); and with 1–3 hs lateral prothoracic setae (lps) + 0–2 lp per side. Sternum (stn1) lightly sclerotised; median ridge absent, transverse ridge well developed; with 0 or 1 hs prosternal setae (stn1s) + 0 or 1 lp per side. Anteprosternal setae (astn1s) and pores absent; with 0 or 1 hs antemesospiracular setae (asp2s) + 0 or 1 lp per side.

Mesothorax: prescutum (prsc) oval, 53–65µm long, 78–115µm wide; sclerotised but not reticulated; prescutal ridge (pscr) well developed anteriorly but narrowing posteriorly; prescutal suture (pscs) poorly developed; with a total of 3 or 4 hs prescutal setae (prscs). Scutum (sct): with a narrow, less sclerotised longitudinal area medially, this broadening posteriorly; rest of scutum sclerotised but not reticulated; distance between prescutum and scutellum 65–83µm; scutal setae (scts) 4–7 hs + 0–2 minute pores on each side; with a distinct small sclerotised apodeme (praa) on anterior margin near prealare (pra); prealar ridge (prar) quite well developed. Scutellum (scl) 63–83µm wide and 38–52µm long; without a scutellar ridge (sclr) or foramen; scutellar setae (scls): 1 or 2 hs + 1 or 2 minute pores on each side; postnotal wing process (pnp) strong and extending laterally. Basisternum (stn2) 135–190µm wide and 75–100µm long; without a median ridge (mdr); bounded anteriorly by a strong marginal ridge (mr), and posteriorly by a strong precoxal ridge (pcr2); with a narrow, short, additional ridge, extending ventrally from pcr2 near articulation with mesocoxa; with 7–16 hs basisternal setae (stn2s), mainly in a broad median band and along anterior margin, each mainly about 8µm long but some up to 21µm; lateropleurite (lpl) narrow; furca (f) well developed, narrow­waisted, arms very divergent and extending about 3/4 way to marginal ridge anteriorly. Mesopostnotum (pn2) well developed; postnotal apophysis (pna) well developed. Area bounded anteriorly by scutellum and laterally and posteriorly by mesopostnotum not sclerotised. Mesepisternum (eps2) not reticulated; subepisternal ridge (ser) long and well developed. Postalare (pa) without reticulations; without postalare setae (pas). Mesothoracic spiracle (sp2): width of peritreme 15–19µm, without associated loculate pores. Postmesospiracular setae (pm2s): with 1–4 hs + 0–2 lp posterior to each spiracle plus 0 or 1 lp medially. Tegula (teg) present, with 1–3 tegular setae (tegs) on each side.

Metathorax: with 2–4 hs metatergal setae (mts) on each side; metapostnotum (pn3) present as a transverse sclerite. Dorsospiracular setae (dss) absent. Dorsal part of metapleural ridge (plr3) present; with small suspensorial sclerites (ss). Posterior part of metapleural ridge well developed; episternum (eps3) sclerotised but without postmetaspiracular setae (eps3s); precoxal ridge (pcr3) well developed, extending medially about 65–75µm, almost to metasternal apophyses; metasternal apophysis (st3a) distinct. Metepimeron (epm3) lightly sclerotised. Antemetaspiracular setae (am3s) absent. Metathoracic spiracle (sp3): width of peritreme 15–19µm, without associated lp. Metasternum (stn3) membranous, with 2–4 hs anterior metasternal setae (amss) + 0 or 1 lp, and 0 or 1 hs posterior metasternal setae (pmss) + 0 or 1 lp on each side.

Wings: hyaline, rather short, 700–900µm long and 250–325µm wide (ratio of length to width 1:0.36; ratio of total body length to wing length 1:0.86); alar lobe (al) well developed; each wing with 2 or 3 hs alar setae (als), plus 2 or 3 circular sensoria (sens) just distal to where medial vein branches from radial vein. Hamulohalteres (h): 66–68µm long, 15–20µm wide; with a single apical hamulus (ham), 50µm long.

Legs: metathoracic legs marginally longest. Coxae (cx): I: 76–100; II: 68–90; III: 73– 96µm long; setae of coxa III: about 9–14 hs; long setae on each coxa not differentiated. Trochanter (tr) + femur (fm): I: 150–196; II: 146–190; III: 148–195µm long; trochanter III with about 5 hs; each trochanter with 3 circular sensoria on each side arranged in a triangle medially and with strong sclerotised ridges for articulation with femur; long trochanter seta 50–75µm long; femur III with about 15–21 hs, some 25–30µm long. Tibia (ti): I: 132–195; II: 137–195; III: 155–223µm; tibia III with a total of about 20–31 setae, of which 1–4 fs, similar to those on antennae; several other setae becoming spur­like on distal third of leg; with 3 or 4 spurs (tibs) on protibia, 2 or 3 on mesotibia and 4 on metatibia, strongest 15–22µm long. Tarsi (ta) two segmented, proximal segment very short and ringlike, length of both segments combined: I: 61–82; II: 61–83; III: 65–88µm long (ratio of length of tibia III to length of tarsus III 1:0.40); tarsus III with 15–18 setae, mainly spurlike + 1 fs; tarsal spurs (tabs) not differentiated, but seta in this position about 20–22µm long; tarsal campaniform pore (tcp) present; tarsal digitules (tdt) as long as claw, with small capitate apices. Claws (c) long and thin, nearly 1.5x width of tarsus, almost straight, without a small denticle (cd); length: III: 23–28µm; claw digitules (cdt) probably present and setose.

Abdomen: segments I–VII: small tergites (at) present across anterior margins of most segments on well­stained specimens; sternites (as) unsclerotised. Caudal extension (ce) of segment VII absent. Dorsal abdominal setae (ads) (totals across segment): segment I: 6 or 7 hs + 0 lp; II: 7 or 8 hs + 0 lp; III–V: 6 or 7 hs + 0 lp; VI: 5 or 6 hs + 0 lp; VII: 3 hs + 0 lp. Pleural setae: dorsopleural setae (dps) on each side: I: 2 hs + 1–5 lp; II–VI: 2 hs + 1 or 2 lp; VII: 4 hs + 1 or 2 lp; ventropleural setae (vps) (on each side): II–VII: 2 hs + 0 lp. Ventral abdominal setae (avs) (totals): II: 2 hs + 0 lp; III–VI: 4–8 hs + 0 lp; VII: 3–7 hs + 0 lp. With a pair of indistinct ostioles (os) laterally between segments VI and VII.

Segment VIII: tergite (at) and sternite (as) sclerotised, latter with a pair of short transverse (or inverted L­shaped) sclerotisations medio­laterally; tergite with 1 pair hs dorsal abdominal setae (ads); sternite without ventral abdominal setae (avs) (rarely a single hs); caudal extension (ce) rounded, with 2 hs pleural setae. Glandular pouches (gp) present, shallow, each with numerous loculate pores spreading out around glandular pouch (gp); with 2 rather long glandular pouch setae (gls), each about 186–235µm long, plus 2 shorter setae, each about 60–75µm long.

Genital segment: penial sheath (ps) short, broadest anteriorly, sides converging to a fairly narrow, blunt apex; covered dorsally by a narrow, elongate membranous area becoming sclerotised posteriorly, probably representing segment IX; with a vertical anal opening (an) at posterior end, about 20µm wide. Length of penial sheath 79–103µm, greatest width 76–90µm. Ventral lateral processes of penial sheath well developed, each with 1–3 short setae; ventral surface with 2 other pairs of short setae, each about 8–9µm long, plus 3 pairs of longer setae (each 16–27µm long) nearer apex. Basal rod (bra) short but distinct, probably lying more or less vertically, perhaps about 25µm long to top of aedeagus (aed) (including heavily sclerotised area which probably represents internal genital aperture (iga)). Aedeagus (aed) more or less parallel­sided, extending to end of penial sheath, about 70–83µm long and about 12µm wide, curved, lying within penial sheath.

Material examined. GREENLAND: Jameson Land, Muslingerbugt, 26.vii.1994, pitfall trap, Jens Böcher: 3/4adΨΨ, 1adɗ + 1/adɗ of Spinococcus calluneti ; as previous, 25.vii.1994, Jens Böcher: 2/5adΨΨ; Evighedsfjord, Kangiussaq, on Viscaria alpina , 20.vii.2003, S.T. Nielsen: 4/6adɗɗ, 1adΨ + pupa; as previous, on Campanula gieseckiana, S.T. Nielsen : 4/9adɗɗ; Sydgrønland (Kap Farvel­omradet, Pamiagdluk, Anordliūitsoq, 30.vii.1970, pitfall trap, Jens Böcher: 1/1adΨ; Itivleq East, Melandrium affine /triflorum, 22.vii.2003, T. Nielsen: 2/5adɗɗ; as previous, no host, 23.vii.2003, S. Langmark: 5/ 11adΨΨ; as previous, Va c ci n iu m sp. and Salix glauca, S.T. Nielsen : 3/6adΨΨ; as previous, 22.vii.2003, on Artemisia borealis, S.T. Nielsen : 3/4adɗɗ + 2 immɗ; Ameralik, Eqaluit Ilordlit, 7.vii.2003, on Coptis trifolia, S.T. Nielsen : 5/5adΨΨ + 4adɗɗ; as previous, 8.vii.2003, on Thymus sp., S.T. Nielsen: 1/1adΨ + 1 immɗ; as previous, on Rumex acetosella, S.T. Nielsen : 3/3adΨΨ, 3adɗɗ + 1 immɗ; Buksefjorden east, 6.vii.2003, no host, S.T. Nielsen: 5/6adΨΨ, 2adɗɗ + 1 immɗ; Fiskefjord, Igdutalik, 11.vii.2003, Potentilla tridentata, S.T. Nielsen : 2/1adɗ + 4 immɗ; Narsarsuaq, 1991, Jens Böcher: 2/3adΨΨ + 2adɗɗ ( ZMUC; BMNH; USNM).

Comment. As both males and females have been collected on the same occasion several times and, as this species appears to be one of the more abundant and widespread species, the identity of this male seems highly probable.

The male of Atrococcus groenlandensis can be separated from other known pseudococcid males from Greenland in possessing: (i) only one pair of glandular pouches; (ii) fleshy setae present only on antennae and legs, not on epicranium; (iii) few or no postmesospiracular setae; (iv) few disc­pores present on pleural region of abdomen; (v) abdominal sternite VIII with antero­lateral sclerotisations, and (vi) fleshy setae on antennae subequal to width of antennal segments with blunt apices.

The males studied here varied quite significantly in size, thus the wide range of measurements.

In the key to adult males of Afifi (1968), this species comes out close to Nipaecoccus .