Stigmacoccus paranaensis Foldi

Hodgson, Chris, Gamper, Heather, Bogo, Amauri & Watson, Gillian, 2007, A taxonomic review of the Margarodoid genus Stigmacoccus Hempel (Hemiptera: Sternorrhyncha: Coccoidea: Stigmacoccidae), with some details on their biology, Zootaxa 1507, pp. 1-55 : 46-49

Stigmacoccus paranaensis Foldi

( Fig. 16 )

Material studied. BRAZIL, Santa Catarina, Florianopolis, Campus of Univ. Fed. de Santa Catarina, on trunk of Schizolobium excelsum , 10.viii.1998, G. Mottana ( BMNH): 1/1adɗ, bred out from prepupa but removed from pupa as a fully-developed adult prior to emerging. In fair condition but with head slightly distorted, legs and antennae probably not fully extended and wings extremely folded and not extended.

Unmounted material. Not known.

Mounted material. As in generic description plus: 3.55 mm long and 0.89 mm wide across prealare. Body setae short, with both hair-like setae (hs) and hairs (hrs); loculate pores (lp) each 5–6 ųm wide, mainly with 3 or 4 loculi, present laterally on abdomen, dorsally on metathorax and with one laterally on prothorax.

HEAD. Additional details to generic description: triangular in dorsal view, length 410 ųm; width across compound eyes about 650 ųm. Dorsally: postoccipital suture (pos) broad; pos with 1 or 2 hs on each side. Median crest (mc) covered in 35–40 setae on each side, mainly hrs but with a few hs (each hs about 20 ųm long; hrs each 25–40 ųm long) but with no loculate pores (lp). Lateral areas of dorsal epicranium (dmep) membranous, with 0 or 1 hs. Laterally: compound eyes (ce) each about 350–375 ųm long, with only about 17 or 18 small to large ommatidia, largest oval, 70 x 60 ųm, smallest round, about 20 ųm. Each ocular sclerite (ocs) with a single ocellus (o) about 45 ųm wide. Ven tr a ll y with typical five–armed cross of ridges formed from ventral midcranial ridge (vmcr), a pair of preocular ridges (procr) plus preoral ridge (pror); setal distribution as follows: mid-cranial ridge (vmcr) with 17 or 18 hs + hrs on each side but no lp, plus a few setae on each antero-lateral membranous area; lateral areas between preocular and preoral ridges without setae; area posterior to preoral ridges with a group of 21 hs.

Antennae (both antennae possibly not fully expanded; structure of each slightly different). Apparently 8- segmented, length 1.45–1.5 mm (ratio of total-body length to antennal length 1:0.4). Scape (sc) 124–140 ųm long; 99–115 ųm wide, with many setae, shortest basally where each about 8 ųm long, increasing to about 30 ųm distally. Pedicel (pd) 145–170 ųm long, finger-like extension 350–380 ųm; with many short fleshy setae (each about 16–30 ųm long); plus 2 or 3 campaniform sensilla (camp) on dorsal surface. Fleshy setae (fs) on more distal segments similar to those on pedicel; lengths of segments III–VIII (ųm): 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.

THORAX. Additional details to generic description: Prothorax. Dorsally: post-tergites (pt) absent but represented by a small area of sclerotisation. Ve n t r a l l y: with a pair of strong cervical sclerites (cv) which do not appear to articulate anteriorly with sclerotised ridges on head. Pleural ridge (plr1) quite long (about 150 ųm long), extending dorsally from articulation with coxa. Prosternum (stn1): median ridge about 265 ųm long. Membranous areas covered in short hs + hrs (both 15–30 ųm long) as in generic description except posterior propleural setae (pl1s) with a single lp on one side; and prosternal setae (stn1s) represented by 1–3 hs on each side. Antemesospiracular setae probably absent.

Mesothorax. Dorsally, prescutum (prsc): length 410 ųm, width 420 ųm; each diagonal oval membranous area lying parallel to prescutal sutures (pscs) about 205 ųm long and 70 ųm wide; prescutum with 3–5 small hs prescutal setae (pscrs) postero-medially on each side and 4 hs medially between membranous areas. Scutum (sct): distance between prescutum and scutellum about 20–25 ųm; scutum with a group of 28–43 hs scutal setae (scts) on each side of antero-lateral margins of scutellum. Scutellum (scl) with 3 hs scutellar setae (scls) on anterior membranous area. Laterally: antero-laterally, each membranous area with a large group of about 50 short hs tegular setae (tegs). Postero-ventral sclerite of mesepisternum possibly without setae. Ve n - trally: basisternum (stn2) 605 ųm long, 700 ųm wide; without a sclerotised median ridge (mdr), but with a groove running almost full length; with a broad band of short basisternal setae (stn2s) medially along groove + small groups of longer setae near lateral margins. Postmesospiracular setae (pm2s): with about 7–11 hs posterior to each anterior spiracle but absent medially. Mesothoracic spiracles (sp2) relatively small, each peritreme 70 ųm broad.

Metathorax. Dorsally: metapostnotum (pn3) 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. Dorsospiracular setae (dss) absent. Laterally: precoxal ridge (pcr3) well developed and extending medio-ventrally about 150 ųm. Metepisternum (eps3) slightly sclerotised, perhaps with a single hs postmetaspiracular seta (eps3s). Postalare setae (pas) absent. Ven t ra l: postmesoprecoxal ridge setae (ppcr2s): 1 or 2 on each side; anterior metasternal setae (amss): about 28 short hs medially; posterior metasternal setae (pmss): about 10 hs. Posterior spiracles (sp3) unclear, probably similar in structure and size to anterior spiracles.

Wings. Almost completely unexpanded but some features visible: with a distinct group of 70+ circular sensoria (sens) just posterior to base of subcostal ridge, 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 (sens) more distally but exact number uncertain; other veins not detected. Alary lobe (al) present and probably well defined. Hamulohalteres (h) each perhaps 300–335 ųm long and 100–115 ųm wide; each with 3 or 4 very hooked hamuli (ham).

Legs. Not fully expanded, all slightly distorted. Details for metathoracic legs: coxa (cx) 292 ųm long; proximal setae noticeably shorter (8–10 ųm long) than those distally (40–50 ųm). Trochanter (tr) about 190 ųm long, without a long trochanter seta but with 10 or 11 campaniform sensilla and many short setae. Femur (fm) 550 ųm long; with transverse grooves or ridges similar to those on antennae but femur not fully extended; with many shortish setae, each 25–35 ųm. Tibia (ti) 760 ųm long; with many spur-like setae laterally and ventrally, many of these bifurcated; other setae laterally and dorsally more flagellate; no campaniform sensilla located about half-way along length; with about 5 tibial spurs (tibs) distally, each sharply pointed, longest about 40–45 ųm long; derm lightly reticulated distally. Tarsus (ta): length of ta1 + ta2 345 ųm; with transverse sclerotisations, particularly distally; tarsal digitules (tdgt) absent or represented by two small, fine setae on dorsal margin near claw. Claw (c) III about 85 ųm long.

ABDOMEN. Additional details to generic description: dorsal abdominal setae (ads) few hs (no hrs found); ventral abdominal setae (avs) also all hs, slightly more frequent; each ads and avs about 15–20 ųm long, but some pleural setae up to 40 ųm long. Loculate pores (lp) restricted to pleural areas. Tubular pores on segments VI and VII each about 36–45 ųm long and 10–15 ųm wide, each duct broadening slightly about half-way along length and with inner end with a knob-like appendage; funnel-shaped opening of each duct with 25–35 smaller, satellite pores (slp), each about 5 ųm wide and 5 ųm long; with 8 tpo on segment VI and 5 on segment VII; each line of large ducts with a transverse line of more than 50 larger setae (length 33–50 ųm) (if similar to other two species, these almost certainly in a group around each tubular pore). Setae as follows: (total across segment) ads (hs): I–VII about 10–20; avs (hs) II–VII 10–30; dorsal pleural setae (dpls) (hs + hrs on each side): I–III 20–24 + 8–12 lp; IV 15 + 5 lp; V and VI 9 + 3 lp; VII 5–7 + 4 or 5 lp; VIII 12 or 13; ventral pleural setae (hs + hrs on each side): I 0; II–VII 3–6; ventral abdominal setae (avs) total hs: II 10; III 19; IV 7; V 26; VI 19; VII 21 and VIII 17. Abdominal spiracles (asp): with a pair of large and obviously sclerotised, oval spiracles on segment VIII (each opening 33x28 ųm wide) but also with tracheae present in at least previous 4 segments (IV–VII) although no opening visible. Anus (an) present medially above base of penial sheath.

Genital segment. Penial sheath (ps) about 470 ųm long, 175 ųm wide anteriorly, narrowing to a blunt apex posteriorly; with many small setae (pss) (each 10–12 ųm long) on both surfaces; also with a small group of small sensoria (psp) at apex. Aedeagus (aed) lightly sclerotised, probably broadest posteriorly, about 290 ųm long, 90 ųm wide towards apex; probably emerging from a ventral groove in penial sheath but this unclear as this area covered in short setae; eversible endophallus (eph) perhaps 1.1 mm long.

Comment. This is the specimen described by Hodgson and Foldi (2006) and the description is repeated here for convenience. However, note that, with males of the other two species of Stigmacoccus having become available, the above description has been modified slightly. In particular, hairs are clearly present on S. paranaensis .

Discussion on adult male stage. The structure of the tubular pores, each with satellite loculate pores, on abdominal segments VI and VII is unique to this family. Other generic characters are: (i) the sclerotised rings on the antennae, (ii) the branched structure of the antennae (otherwise only known in Dimargarodes , but Stigmacoccus has lateral extensions or branches from the pedicel as well as on flagellar segments), (iii) the odd structure of the compound eyes, with relatively few ommatidia, these of rather variable size, (iv) the large group of wing sensoria close to the base of the wing, and (v) the membranous areas on the mesothorax – with one on either side of the prescutum and 2 or 3 on the scutellum.

General discussion. It is clear that the genus Stigmacoccus has a number of unique characters (abundant large segmented pores on posterior abdominal segments of adult female; structure of the anal complex of both the 1st-instar nymph and cyst stages; antennae with finger-like extensions on all segments bar the scape on the adult male and also the satellite ducts around the tubular ducts on abdominal segments VI and VII on the adult male). All of the above species share these characters – indeed, the species are all very similar. However, from this study it is also clear that the two Brazilian species ( S. asper and S. paranaensis ) have more in common than they share with the Mexican species, S. garmilleri . The latter species differs from the former two in having (character-state on S. asper and S. paranaensis in brackets): (i) hairs on derm near margins of loculate pores (absent); (ii) antennae on adult female 10-segmented (6–9 segmented); (iii) vaginal wall apparently without sclerotised loculate pores (present); (iv) probable absence of small segmented pores in mouth area on adult females (present); (v) absence of loculate pores along margin of vagina (present); (vi) anal complex of cyst with a wide sclerotised band laterad to abdominal spiracles VIII (absent); (vii) anal complex on cysts without an outer ring of either cone- or bollard-like spines (present); (viii) anal complex on 1st-instar nymph with a double band of tubercle-like pores (only 1 ring of pores); (ix) much longer antennae on adult male (ratio of total-body length to antennal length 1:0.65 on S. garmilleri , but only about 1:0.4 on other two species); (x) penial sheath rather broad, about 1.5 times longer than broad (2.5 times longer than broad); (xi) hairs abundant on venter of abdomen of adult male (absent), and (xii) prosternal setae (with loculate pores) in a large group on either side of prosternum (very few or absent). However, as there appear to be at least three other undescribed species in South and Central America, these differences could represent the two ends of a cline.

Figures

FIGURE 16. Adult male Stigmacoccus paranaensis Foldi. For lettering, see Figs 14 & 15.