Trionymus bocheri, Gertsson & Hodgson

Hodgson, Chris, 2005, The adult males of Coccoidea (Hemiptera: Sternorrhyncha) known from Greenland, Zootaxa 907, pp. 1-48 : 19-24

TRIONYMUS BOCHERI Gertsson & Hodgson ( Fig. 4 )

Trionymus bocheri Gertsson & Hodgson, 2005: 8 .

(Described from 3 specimens, mostly in fair to good condition).

Live appearance: not recorded.

Mounted material: small, total body length about 0.82–0.88 mm; antennae short, slightly less than half total body length, with rather short, stout fleshy setae (fs); length of fs on antennae subequal to width of antennal segments; body with few setae, all hair­like (hs) apart from a few fs on head and legs; loculate pores (lp) each with mainly 3–5 loculi and each 6–7µm wide, on thorax and abdomen only; many with a nearby minute pore.

Wings shorter than total body length, about 0.8x total body length and about 0.3x as wide as long. Abdomen with 1 pair of glandular pouches.

Head: roundly triangular, apex of triangle pointing anteriorly; probably with ventral eyes on a distinct ventral bulge; length about 116–132µm; width across genae about 144– 170µm. Median crest (mc) absent; postoccipital ridge (por) represented by a thin Ushaped ridge at posterior end of dorsal part of epicranium (dmep); with (on each side) 1 or 2 fs, 6–8 hs dorsal head setae (dhs) plus 1–5 simple pores mesad to each scape. Midcranial ridge: dorsal ridge (dmcr) faint, long and narrow, extending posteriorly well past posterior margin of dorsal simple eyes (dse) and almost reaching post­occipital ridge (por); ventral midcranial ridge (vmcr) faint or absent; lateral arms (lmcr) well developed; ventral midcranial ridge setae (vmcrs) not separated from ventral head setae (vhs), see below. Genae (g) not reticulated; with 0 or 1 fs + 3 or 4 hs genal setae (gs) on each side. Eyes: two pairs of simple eyes, subequal in size; dorsal eyes (dse) each approximately level with ventral simple eyes (vse); each 20–22µm wide. Ocelli (o) fairly pronounced, situated laterally, each 12–16µm 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) dorsally very short; ventrally forming interocular ridge (ior). Postocular ridge (pocr) strongly developed, extending antero­laterally, ending posterior to inner margin of dse; each fusing with or just ventral to each ocellus. Dorsal ocular setae (docs) absent. Ventral head setae (vhs): with (on each side) 2–6 fs, 6–8 hs ventral head setae (vhs) (plus ventral mid­cranial ridge setae (vmcrs)) + 0 or 1 small simple pores, distributed anterior and laterad to vse; with 0 or 1 hs between vse; longest hs up to about 25µm; fs about 8–15µm long. Preoral ridge (pror) probably weak, with ventral groove and cranial apophysis (ca) arising anteriorly; length of latter combined about 40–45µm.

Antennae: 10 segmented and filiform (one specimen 9 segmented on one side); 375– 450µm long (ratio of total body length to antennal length 1:0.48). Scape (scp) approximately square, with pedicel arising anterolaterally: 25–30µm long and 33–36µm wide, with 2 hs dorsally and 2 ventrally and medially. Pedicel (pdc): length 43–49µm, width 28– 30µm; with concentric ridges on distal end; with 9 fs, 7 hs + campaniform pore. Segments III–X each about 16–18µm wide; lengths of segments (µm): III: 36–47; IV: 30–33; V: 33– 35; VI: 35–40; VII: 35–37; VIII: 40–44; IX: 44–50; fs about 15–20µm long (longest nearer apex); approximate number of setae per segment: III: 0–3 fs + 0–3 hs; IV: 3 fs + 1 hs; V: 4–5 + 1 or 2 hs; VI: 4–6 fs, 0 or 1 hs + 2–5 caps; VII: 4–6 fs, 0 hs + 4 or 5 caps; VIII: 4–6 fs, 0 hs, 5 caps + 1 bristle (abr) (towards distal end); IX: 6 fs, 0 hs, 5 or 6 caps + 1 bristle (abr) (towards distal end). Segment X with a slightly narrowed apex: length 60–65µm; with 3 fs, 1 hs, 5 caps + 3 large and 2 small bristles (abr), clearly differentiated from fs; with 1 sensilla basiconica (sb) on apex.

Thorax. Prothorax: pronotal ridges (prnr) well developed and touching dorsally; pronotal sclerite (prn) represented by a long finger­like process extending postero­laterally, length about 10–12µm; without lateral pronotal setae (lpns). Medial pronotal setae (mpns): with 3 hs + 0 lp on each side; post­tergite (pt) distinct, each with 0–2 hs post­tergital setae (pts). With (on each side) 2 hs lateral prothoracic setae (lps), 2 lp + 2 minute pores anteriorly and 2 or 3 hs, 0 or 1 lp + 0 or 1 minute pores posteriorly. Sternum (stn1) lightly sclerotised; median ridge absent, transverse ridge well developed; with 1 or 2 hs prosternal setae (stn1s) on each side. Anteprosternal setae (astn1s): 0 or 1 hs medially; with 2 hs antemesospiracular setae (asp2s) on each side.

Mesothorax: prescutum (prsc) roughly oval, 41–50µm long, 75–95µm wide; sclerotised but not reticulated; prescutal ridge (pscr) well developed laterally, narrowing posteriorly; prescutal suture (pscs) absent; with a total of 2–4 hs prescutal setae (prscs). Scutum (sct): without any signs of a less sclerotised area medially; sclerotised but not reticulated; distance between prescutum and scutellum 60–80µm; scutal setae (scts): 2–4 hs on each side; with a distinct sclerotised apodeme (praa) on anterior margin near prealare (pra); prealar ridge (prar) quite well developed. Scutellum (scl) 50–70µm wide and 27–33µm long; without a scutellar ridge (sclr) or foramen; scutellar setae (scls): 1 pair hs; postnotal wing process (pnp) strong and extending laterally. Basisternum (stn2) 120–135µm wide and 70–95µm long; without a median ridge (mdr); bounded anteriorly by a strong marginal ridge (mr) and posteriorly with a strong precoxal ridge (pcr2); with a narrow, short, additional ridge, extending ventrally from pcr2 near articulation with mesocoxa; with a total of about 2–4 hs anteriorly and medially and 2 hs posteriorly, each about 11–13µm long; lateropleurite (lpl) short and 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 16–18µm, without associated loculate pores. Postmesospiracular setae (pm2s): with 2–5 hs posterior to each spiracle plus 5 or 6 hs medially; without lp. Tegula (teg) present, with 1–3 hs tegular setae (tegs) on each side.

Metathorax: with 1–3 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; without postmetaspiracular setae (eps3s); precoxal ridge (pcr3) well developed, extending medially about 38–48µm; metasternal apophysis (st3a) very indistinct or absent. Metepimeron (epm3) well developed. Antemetaspiracular setae (am3s) absent. Metathoracic spiracle (sp3): width of peritreme 16–18µm, without associated lp. Metasternum (stn3) membranous, with 1 or 2 pairs of hs anterior metasternal setae (amss), and 0 or 1 hs posterior metasternal setae (pmss) on each side.

Wings: hyaline, rather short, about 700µm long and 230µm wide (ratio of length to width 1:0.33; ratio of total body length to wing length 1:0.82); alar lobe (al) well developed; each wing with 2 hs alar setae (als), plus 1 or 2 circular sensoria (sens) just distal to where medial vein branches from radial vein. Hamulohalteres (h): 50–55µm long, 12– 17µm wide; with a single apical hamulus (ham), 35–38µm long.

Legs: metathoracic legs marginally longest. Coxae (cx): I: 60–70; II: 55–70; III: 60– 70µm long; setae of coxa III: 1 fs + 10 or 11 hs; long setae on each coxa not differentiated. Trochanter (tr) + femur (fm): I: 135–148; II: 124–145; III: 130–145µm long; trochanter III with 5 or 6 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 50–55µm long; femur III with about 0 or 1 fs + 10–14 hs, some 20µm long. Tibia (ti): I: 100–120; II: 91–124; III: 120–145µm; tibia III with a total of about 1 or 2 fs + 8–10 setae, several becoming spur­like on distal end of leg; with 2 spurs (tibs) on protibia and 3 or 4 on meso­ and metatibia; strongest 17µm long. Tarsi (ta) two segmented, proximal segment very short and ring­like, length of both segments combined: I: 55–60; II: 52–58; III: 55–60µm long (ratio of length of tibia III to length of tarsus III 1:0.43); tarsus III with 0–2 fs + 7 setae, many spur­like; tarsal spurs (tabs) not differentiated; tarsal campaniform pore (tcp) present; tarsal digitules (tdt) marginally longer than claw, with small capitate apices. Claws (c) long and thin, clearly longer than width of tarsus, almost straight, without a small denticle (cd); length: III: 20–25µm; claw digitules (cdt) setose.

Abdomen: segments I–VII: tergites (at) unsclerotised; small sternites (as) present on VI and VII. Caudal extension (ce) of segment VII absent. Dorsal abdominal setae (ads) (totals across segment): segments I–VII: 3 or 4 hs. Pleural setae: dorsopleural setae (dps) on each side: I: 2 hs + 1 lp; II–VII: 2–4 hs + 0 or 1 lp (one seta on VII rather long, up to about 45µm); ventropleural setae (vps) (on each side): II: 0 hs; III–VII: 2–4 hs. Ventral abdominal setae (avs) (totals): II: 2 hs; III–VII: 3–4 hs. With a pair of fairly distinct ostioles (os) laterally between segments VI and VII.

Segment VIII: tergite (at) and sternite (as) sclerotised; sternite with a pair of antero­lateral sclerotisations; tergite with 1 or 2 pairs hs dorsal abdominal setae (ads); sternite with 0 or 1 hs ventral abdominal setae (avs); caudal extension (ce) rounded, with 3 hs pleural setae, longest up to 40–50µm. Glandular pouches (gp) present, shallow, each with many loculate pores spreading out around glandular pouch (gp); with 2 rather long glandular pouch setae (gls), each about 230µm long, plus 1 or 2 shorter setae, each 55–135µm 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 which becomes sclerotised posteriorly, probably part of segment IX; with a vertical anal opening (an) at posterior end. Length of penial sheath 85–105µm, greatest width about 70–75µm (but no specimen lying dorsoventrally). Ventral lateral processes of penial sheath apparently absent; ventral surface with 2 or 3 other pairs of short setae, each about 7–10µm long; with 2 or 3 pairs of longer setae (each 16–20µm long) on latero­dorsal surface.

Basal rod (bra) short but distinct, lying more or less vertically. Aedeagus (aed) more or less parallel­sided, extending past end of penial sheath, about 83µm long, with a membranous apex; curved, lying within penial sheath.

Material examined. GREENLAND: Narsarsuaq, 1991, Jens Böcher: 4/3adΨΨ + 1adɗ (+ 3ΨΨ Eriococcus munroi ) ( ZMUC; BMNH).

Comment. The identity of these males is no more than probable. They were collected at the same time as the female but several other species have the same collection data. However, the males and females of the other species were also collected at other times and places and so, by elimination, these males seem most likely to belong to T. bocheri .

The males of T. bocheri share with T. elymus the presence of fleshy setae on both dorsal and ventral surfaces of head but can be separated from the latter by the following combination of characters (character­states on T. elymus in brackets); (i) small simple pores most abundant on dorsal surface of head (only on ventral surface); (ii) post­tergites each with 2 hs (each with 4 hs setae); (iii) with 1 or 2 pairs of anterior metasternal setae (more than 10); (iv) 3rd antennal segment shorter than 2nd (longer), and (v) 6 or fewer fs on each antennal segment (most segments with about 10). For a comparison with the male of T. thulensis see under that species.

Figures

FIGURE 4. Adult male of Trionymus bocheri Gertsson & Hodgson. Where A = cranial apophysis; D = convex simple pore on head; E = fleshy seta; G = multilocular disc­pores; H = minute pore; J = apical antennal segment; K = dorsal and ventral view of genital segment. And where astn 1 s = anteprosternal setae; caps = capitate setae; fs = fleshy setae; hs = hair­like setae; lps = lateral prothoracic setae; lpns = lateral pronotal setae; mpns = medial pronotal setae; pts = post­tergital setae, and stn 1 s = prosternal setae. For most other abbreviations see Figs. 1 & 3.