Stigmacoccus sp.

Hodgson, Chris & Foldi, Imre, 2006, A review of the Margarodidae sensu Morrison (Hemiptera: Coccoidea) and some related taxa based on the morphology of adult males, Zootaxa 1263 (1), pp. 1-250 : 1-250

Stigmacoccus sp.

( Fig. 16 )

Material studied BRAZIL, Sta Caterina , Florianopolis campus of U. Fed. de Sta Caterina, on trunk of Schizolobium excelsum (Leguminosae) , 10.viii.1998, G. Mottana ( BMNH): 1/1ad ♂, bred out from prepupa but removed from pupa as a fully­developed adult without emerging. In fair condition but with the head slightly distorted, legs and antennae probably not fullyextended and wings extremely folded and not extended at all ).

Mounted material

Large, 3.55 mm long, 0.89 mm wide across prealare. Body sparsely covered in quite short hair­like setae (hs), most about 15–35 m long; collared setae (cs) and hairs (hrs) absent; loculate pores (lp) present laterally on abdomen, dorsally on metathorax and with 1 laterally on prothorax, each 5–6 m wide, mainly with 3 or 4 loculi. Convex pores (cp) and minute pores absent. Antennae very unusual, apparently 8 segmented, with pedicel and 6 flagellar segments, each with long finger­like projections, covered in numerous short fleshy setae (fs), none with satellite setae (sats). Sclerotised areas of body without nodulations. Legs well developed and setose, many setae spur­like and bifurcated on tibia; tarsus 2 segmented; claws without a denticle; claw digitules setose. Abdominal segment I not visible ventrally; abdomen without lateral caudal extensions; terga of segments VI and VII with a line of large tubular ducts, each duct with a group of small, satellite tubular ducts around tubular pore opening. Penial sheath more or less terminal.

Head

Triangular in dorsal view, length 410 m, width across compound eyes about 650 m. Dorsally: postoccipital suture (pos) broad, extending across posterior part of epicranium (dmep) but perhaps without a postocciput (poc); pos with 1 or 2 hs on each end. Midcranial ridge (mcr) quite broad, extending posteriorly almost to postoccipital suture (pos), sclerotised but without striations or reticulations; mcr covered in 35–40 hs setae on each side (each seta about 20 m long) but with no lp. Lateral areas of dorsal epicranium (dmep) membranous, with 0 or 1 hs. Preocular ridge (procr) probably absent dorsally or represented by ridge along dorsal margin of each compound eye. Laterally: compound eyes (cde) each about 350–375 m long, with only about 17 or 18 small to large ommatidia (i.e. very variable in size). Each cde with a broad, barely sclerotised, ocular sclerite (ocs) along dorso­posterior margin, each with a single ocellus (o) about 45 m wide; without obvious postocular ridges (pocr) along dorsal margin of ocs; ventral projection (p) absent. Ventrally with a series of strongly sclerotised ridges forming a five­armed cross, composed of: (i) a ventral midcranial ridge (vmcr) anteriorly, which fuses posteriorly with (ii) a pair of lateral preocular ridges (procr) and (iii) a pair of preoral ridges (pror) posteriorly. Ventral part of epicranium (vmep) otherwise mainly membranous; setal distribution as follows: mid­cranial ridge (vmcr) with 17 or 18 hs on each side but no lp, plus a few setae on each antero­lateral membranous area; lateral areas between preocular and preoral ridges without setae; area posterior to preoral ridges with a group of 21 hs. Cranial apophysis (ca) not visible but probably short and broad. Mouth (m), tentorial bridge (tb) and anterior (ata) and posterior tentorial arms (pta) not detected. Without ventral sclerites (vs), unless fused to cervical sclerite.

Antennae (both antennae possibly not fully expanded; structure of each slightly different): apparently 8­segmented, length 1.45–1.5 mm (ratio of total­body length to antennal length 1:0.4); segments II (pedicel) to VIII each with a long finger­like lateral extension; each extension with numerous narrow, often incomplete, sclerotised dermal rings, each ring with 1 or 2 fleshy setae (fs). Scape (scp) 124–140 m long, 99–115 m wide, sclerotised, with many setae, those basally short, about 8 m long, increasing to about 30 m distally; without bifurcated setae (bs); each scape with a sclerotised articulatory socket with head. Pedicel (pdc) 145–170 m long, finger­like extension 350–380 m; with many short fleshy setae (each about 16–30 m long), none with satellite setae (sats), plus 2 or 3 campaniform sensilla (camp) on dorsal surface. Setae on more distal segments similar to those on pedicel; lengths of segments III–VIII (m): III: 145–155, extension 500–525; IV: 135–145, extension 495–540; V: 125–150, extension 485–505; VI: 145–210, extension 490–700; segments VII and VIII on each antenna different but length of VII plus extension about 410–495 and VIII about 310 on both antennae. Extensions on apical four segments each with a few antennal bristles (ab), each noticeably thicker than fs.

Thorax

Prothorax: neck broad. Dorsally: with a strong pronotal ridge (prnr) which extends uninterrupted across hind part of neck, more or less reaching cervical sclerite (cv) ventrally. Post­tergites (pt) absent. Laterally with a pair of strong cervical sclerites (cv) which do not appear to articulate anteriorly with sclerotised ridges on head; each cv with a proepimeron (epm 1) about half­way along length on dorsal margin. Pleural ridge (plr 1) quite long (about 150 m long), extending dorsally from articulation with coxa. Ventrally: prosternum (stn 1) with a well­sclerotised median ridge about 265 m long, which broadens posteriorly but without obvious sternal apophyses (stn 1 a). Membranous areas covered in short setae (each 15–30 m long) as follows: dorsally with a group of median pronotal setae (mpns), just anterior to prescutum; also with a sparse band of lateral pronotal setae (lpns) just posterior to pronotal ridge (prnr); with groups of anterior and posterior propleural setae (pl 1 s) on each side, latter with a single lp on one side; with a small group of possible post­tergital setae (pts) on each side posterior to lpns; ventrally with a group of anteprosternal setae (astn 1 s) just anterior to prosternum (stn 1) but prosternal setae (stn 1 s) laterad to prosternum absent. Antemesospiracular setae (asp 2 s) probably absent.

Mesothorax: dorsally: prescutum (prsc) large and nearly as long as broad (length 410 m, width 420 m); mesoprephragma (phr 1) narrow; posteriorly rather rounded, with 2 diagonal, oval membranous areas lying parallel to prescutal sutures (pscs), each about 205 m long and 70 m wide; prescutal ridges (pscr) short; prescutal sutures (pscs) quite strong postero­medially; prescutum with 3–5 small hs prescutal setae (prscs) postero­ medially on each side and 4 hs medially between membranous areas. Scutum (sct) sclerotised throughout, very short medially, prescutum almost touching scutellum (distance 20–25 m); with a group of 28–43 hs scutal setae (scts) just laterad to lateral margins of scutellum; without setae or pores near lateral margins. Scutellum (scl) triangular; scutellum extending laterally to posterior notal wing process (pnp); with 3 membranous areas, 2 laterally and 1 anteriorly; with 3 hs scutellar setae (scls) on anterior membranous area. Laterally: prealare (pra) elongate. Tegula (teg) well developed, each with a large group of about 50 short hs tegular setae (tegs). Mesopleural ridge (plr 2) well developed, with a deep pleural apophysis (pla 2). Mesepisternum (eps 2) not nodulated. Mesothoracic spiracles (sp 2) relatively small, each peritreme 70 m broad; muscle plate well sclerotised. Ventrally: basisternum (stn 2) large, length 605 m, width 700 m; without a sclerotised median ridge (mdr); bounded anteriorly by a well­developed marginal ridge (mr) and posteriorly by well­developed precoxal ridges (pcr 2); basisternal setae (stn 2 s) short, in a broad band medially plus small groups of longer setae near lateral margins; furca (f) moderately narrow ventrally, slightly waisted, with long arms, which diverge strongly; lateropleurite (lpl) indistinct, possibly absent; subepisternal ridge (ser) weak; setae in this area absent. Postmesospiracular setae (pm 2 s): with about 7–11 hs posterior to each anterior spiracle; none medially. Wing sclerites: showing nothing distinctive.

Metathorax: dorsally: metapostnotum (pn 3) possibly absent; with a band of about 90 hs metatergal setae (mts) + about 20 lp in a dense group extending across median part of segment. Laterally: dorsospiracular setae (dss) absent. Suspensorial sclerites (ss) elongate. Pleural ridge (plr 3) well developed; precoxal ridge (pcr 3) well developed and extending about 150 m medio­ventrally. Metepisternum (eps 3) slightly sclerotised, perhaps with a single hs postmetaspiracular seta (eps 3 s); metepimeron (epm 3) strong, extending dorsoposteriorly around metacoxae. Posterior spiracles (sp 3) unclear, probably similar in structure and size to anterior spiracles. Ventrally: metasternum (stn 3) represented by a narrow transverse sclerotisation with distinct lateral apophyses (stn 3 a). Postmesoprecoxal ridge setae (ppcr 2 s): 1 or 2 on each side; anterior metasternal setae (amss): about 28 short hs medially; posterior metasternal setae (pmss): about 10 hs.

Wings: almost completely unexpanded but some features visible: with a distinct group of 70+ circular sensoria (sens) just posterior to base of subcostal thickening (sclt), plus 1 or 2 hs alar setae (als) associated with group of sensoria, plus a further 3 or 4 hs a little more laterally; also with some alar sensoria more distally but exact number uncertain; other veins not detected. Alar lobe (al) present and probably well defined. Hamulohalteres (h) mainly lightly sclerotised, perhaps broadest about middle; length perhaps 300–335 m, width 100–115 m; each with 3 or 4 hooked hamuli (ham).

Legs: possibly not fully expanded as all appear slightly distorted. Details for metathoracic legs: coxa (cx) 292 m long; each with many setae, those proximally noticeably shorter (8–10 m long) than those distally (40–50 m). Trochanter (tr) about 190 m long, without a long trochanter setae but with 10 or 11 campaniform sensilla (camp) and many short setae; articulation with femur indistinct. Femur (fm) 550 m long; with transverse grooves or ridges (similar to those on antennae) and with many shortish setae, each 25– 35 m. Tibia (ti) 760 m long; with many spur­like setae laterally and ventrally, many of these bifurcated; other setae laterally and dorsally more flagellate; with about 5 tibial spurs (tibs) distally, each sharply pointed, longest about 40–45 m long; derm distally lightly reticulated. Tarsi (ta) clearly 2 segmented, proximal segment (ta 1) very short and triangular; length of ta 1 + ta 2 345 m; with a tarsal campaniform sensillum (camp) (on segment ta 2); with bifurcated setae (bs) along ventral margin; other setae as on tibia; with transverse sclerotisations, particularly distally; tarsal spurs (tabs) undifferentiated; tarsal digitules (tdgt) absent or represented by 2 small, fine setae on dorsal margin near claw. Claws (c) normal, without a denticle (cd); claw III about 85 m long, with 2 very short, fine, setose digitules (cdgt).

Abdomen

With no caudal extensions, margins of segment VIII rounded. Tergites (at) absent but with some sclerotisation apparent between segments, particularly between VI and VII; sternites (as) only really noted between metathorax and segment II, but with some diagonal sclerotisations apparent mediolaterally between segments II & III, III & IV, IV & V and V & VI; pleurites (apt) absent. Dorsal abdominal setae (ads) few; ventral abdominal setae (avs) slightly more frequent; all ads and avs hs, each about 15–20 m long, but some pleural setae up to 40 m long. Loculate pores (lp) restricted to pleural areas. Setae as follows: ads (total hs across segment): I–VII about 10–20; dorsal pleural setae (dpls) on each side: I–III 20–24 hs + 8–12 lp; IV 15 hs + 5 lp; V and VI 9 hs + 3 lp; VII 5–7 hs + 4 or 5 lp; VIII 12 or 13 hs; ventral pleural setae (on each side): I 0; II–VII 3–6 hs; ventral abdominal setae (avs) total hs: II 10; III 19; IV 7; V 26; VI 19; VII 21 and VIII 17. Additionally, dorsum of segments VI and VII each with a line of large tubular ducts (tdc) (each about 36–45 m long, 10–15 m wide), each duct broadening slightly about half­way along length and with inner end with a knob­like extension; dermal opening of each duct probably funnel­shaped, into which open 25–35 smaller satellite ducts, each about 5 m wide and 5 m long, apparently similar to small tubular ducts; with about 8 tdc on segment VI and 5 on segment VIII; each line of large ducts with a transverse line of more than 50 larger setae (length 33–50 m) along anterior margin (although they appear posterior on specimen as ducts in a dermal fold). Abdominal spiracles (asp): with a pair of large and obviously sclerotised, oval spiracles on segment VIII (each opening 12–15 x 10–12 m) but also with tracheae present in previous 4 segments (IV–VII) although no opening visible. With (on each side) a strong (possibly internal) sclerotisation extending from anterior margin of penial sheath posteriorly to margin of segment VIII and then anteriorly, possibly fusing with diagonal sternite between segments VII and VIII.

Genital segment: anus (an) present medially above base of penial sheath. Penial sheath (ps) sclerotised, extending posteriorly from beneath segment VIII; ps about 470 m long, 175 m wide anteriorly, narrowing to a blunt apex posteriorly; with many small setae (pss) (each 10–12 m long) on both surfaces; also with a small group of small sensoria (psp) at apex. Aedeagus (aed) lightly sclerotised, probably broadest posteriorly; about 290 m long, 90 m wide towards apex; probably emerging from a ventral groove in penial sheath but this unclear as this area covered in short setae; basal rod (bra) possibly absent; a long setiferous, eversible endophallus (eph) present internally, perhaps 1100 m long.

Comment

The adult male of this undescribed species of Stigmacoccus is very similar to that of S. asper Hempel (see Foldi, 1999) but differs as follows (character­state on S. asper in brackets): (i) ventral part of epicranium with mid­cranial ridge and distinct preocular and preoral ridges, forming a 5 armed star (ridges indistinct, with no 5­armed star); (ii) ventral sclerite (vs) apparently absent (distinct ventrally mesad to each compound eye); (iii) posttergite absent (present); (iv) compound eye strongly convex (much less convex); (v) basisternum without a median ridge (with a median ridge, although incomplete anteriorly and posteriorly); (vi) hamulohalteres with 3 or 4 hamuli (perhaps only 2 or 3); (vii) distinct sclerotised spiracular openings visible on abdominal segment VIII (without any distinct sclerotised spiracles), and (viii) scutellum with 3 membranous areas, 1 anteriorly and 2 laterally (anterior membranous area absent). It is possible that some of these differences are due to this specimen of Stigmacoccus species not having emerged properly, although this seems unlikely as most structures appear to be well developed.

The most distinctive features of male Stigmacoccus based on these two species are: (i) divided antennae (otherwise only known on species of Neomargarodes ); (ii) compound eyes with very few large ommatidia; (iii) two oval membranous areas postero­laterally on prescutum; (iv) shape of tubular ducts on abdominal segments VI and VII, with associated satellite tubular ducts; (v) presence of diagonal sclerotisation ventrally on abdominal segment VIII, and (vi) large group of alar sensoria near base of each wing. These character­states are significantly different from those of the Xylococcidae.

The only other species in the genus Stigmacoccus is S. garmilleri Foldi (Foldi, 1995) but the males have yet to be described.

KUWANIIDAE MacGillivray, 1921

Morrison (1928) assigned the tribe Kuwaniini MacGillivray to the subfamily Margarodinae . Koteja (1974) raised it to family level.

Figures

FIGURE 16. Male Stigmacoccus sp. Letters as for Fig. 6 except U = section of an antennal segment showing sclerotised rings. (Note wings not fully expanded).