Dimargarodes tanganyicus Jakubski, 1965

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

Dimargarodes tanganyicus Jakubski

( Fig. 8 )

Dimargarodes tanganyicus Jakubski, 1965: 97 .

Material studied

TANGANYIKA ( TANZANIA): no details but perhaps collected by Eric Burtt ( BMNH): 3/5 ad ♂♂ (in fair to poor condition). Details given by Jakubski: Old Shinyanga, no host, 9.xii.1954, E. Burtt .

Mounted material

Large, 3.6–4.5+mm long, and 1.0–1.15 mm wide across prealare. Body unusually broad in prothoracic region. With a pair of large compound eyes. Setae on body of 1 type, broad basally and here considered to be fleshy (fs), length 20–85 m, longest anteriorly; without hair­like setae (hs) (except on legs and on base of scape and coxae, where extremely short); hairs (hrs) extremely few or absent; collared setae (cs) and pores absent. Antennae long, about 3/4s total­body length, covered in numerous short setae. Sclerotised areas mostly without nodulations. Legs all exceptionally well developed, particularly all femurs but with anterior legs fossorial; all legs without bifurcated setae (bs); tarsi 1 segmented; posterior tibia and tarsus with some very broad, blunt spines; claws trifurcate and broadly attached to tarsus; claw digitules acute. Abdominal segment I not visible on venter; with tubular ducts on segments VI and VII; without lateral caudal extensions. Penial sheath strongly sclerotised, broad basally and tapering.

Head

Triangular in dorsal view, length 350–415 m, width across compound eyes 590– 700 m. Dorsally with a well­developed postoccipital suture (pos) extending across posterior part of epicranium; dorsal surface of head sclerotised immediately anterior to epicranium otherwise dorsomedial part of epicranium (dmep) barely sclerotised. Postocciput (poc) possibly represented by an area of light sclerotisation just posterior to postoccipital suture. Midcranial ridge (mcr) very short or absent. Dmep with 9–21 fs (each 40–80 m long) + 0–2 hrs dorsal head setae (dhs) on each side posterior to each scape. Pores absent. Laterally with a pair of large compound eyes (cde), each more or less oval in shape, but much broader ventrally, where they nearly meet; each with about 100–120 ommatidia (each ommatidium 30 x 23 m wide); each cde about 186–210 m long. Each compound eye (cde) with a narrow, heavily sclerotised, ocular sclerite (ocs) along posterolateral margins, each ocs with a single, relatively small ocellus (o) dorsally, width 28– 35 m. Preocular ridge (procr) probably running posteriorly along dorsal margin of cde. Postocular ridge (pocr) present posterior to each ocular sclerite (ocs), extending from near each ocellus to posterior margin of each compound eye; a short sclerotised ventral projection (p) present extending posteriorly from pocr. Ventrally with a strong ventral midcranial ridge (vmcr), which divides between compound eyes (cde), each arm extending anteriorly past inner margin of each scape; vmcr extending posteriorly between compound eyes and nearly reaching preoral ridge (pror); lateral margins of vmcr lightly sclerotised, with 20–28 fs on each side; preocular ridges (procr) probably running along ventral margin of each compound eye; preoral ridge (pror) represented by a short, narrow, strongly sclerotised transverse ridge posteriorly between compound eyes; ventral plate (vp) present medially just posterior to pror, with a narrow sclerotised ridge along each antero­lateral margin. Cranial apophysis (ca) not detected. Mouth (m) opening membranous, just posterior to ventral plate. Tentorial arms (ata & pta) represented by 2 pairs of barely sclerotised openings and fine tubes, situated just behind and laterad to mouth. Tentorial bridge (tb) and tentorial apodemes not detected. Ventral sclerites (vs) possibly represented by a sclerotisation at anterior apex of each cervical sclerite (cv).

Antennae: 10 segmented; length 2.7–3.0 mm (ratio of total­body length to antennal length 1:0.7). Scape (scp) 155–170 m long, 175–220 m wide, sclerotised, each with about 20 fs, each about 40–75 m long, + 10–12 very small setae near basal margin on dorsal surface. Pedicel (pdc) 120–150 m long, 124–140 m wide, articulating with scape; with about 15–20 fs, 11 or 12 basiconic sensilla (bass) ventrally and 2 campaniform sensilla (camp) dorsally. Segments III–X of flagellum all of approximately similar width, each 88–150 m wide; each segment with (on ventral surface) numerous shorter setae, each clearly hollow towards base, with sclerotised walls and without a sclerotised basal socket, length 20–30 m; these becoming longer (length 35–50 m) and more fleshy looking on dorsal surface, where setae rather less numerous; segment IV also with a group of 11–18 coeloconic sensilla (cos) ventrally, mainly at distal end; segment lengths (m): III 190–215; IV 255–305; V 285–335; VI 310–405; VII 345–425; VIII 360–405; IX 330–405; X 350–430. Satellite setae (sats), capitate setae (caps) and bristles (ab) all absent.

Thorax

Prothorax: largely membranous but lateral margins mildly sclerotised anteriorly and posteriorly; prothorax separated from head by a broad neck, with no indications of a cervical groove. Dorsally with a pair of large, approximately triangular, quite heavily sclerotised, post­tergites (pt). Pronotum (prn) represented by a single sclerotised bar dorsally, more or less overlying ventral plate. Ventrally with a pair of cervical sclerites (cv), strong basally near coxae, with a proepimeron (epm 1) medially, terminating in a rather triangular, sclerotised point, which appears to touch posterior margin of each compound eye (ventral sclerite (vs)?); cv with an area of small convex nodulations laterally near head. Pleural ridge (plr 1) and pleural apophysis (pla 1) small. Structure of prosternum (stn 1) uncertain, but apparently without a strong median ridge but with some sclerotisation posteriorly. Pores absent. Setae as follows: median pronotal setae (mpns) on pronotum: 5–14 pairs fs + 0–2 hrs; each post­tergite with 10–22 fs post­tergital setae (pts) + some minute pores; laterally with about 19–25 fs anterior propleural setae (apl 1 s) and 40–60 fs posterior propleural setae (ppl 1 s) on separate areas of mild sclerotisation; setae apparently absent ventrally.

Mesothorax: dorsally: prescutum (prsc) large and oval (length 250–290 m, width

380–600 m); lightly nodulated; mesoprephragma (phr 1) narrow; prescutal ridges (pscr) short, mesad to each prealare (pra) and extending anteriorly to mesoprephragma (phr 1); prescutal sutures (pscs) weak; prescutum without prescutal setae (prscs). Scutum (sct) sclerotised throughout and nodulated on anterolateral margin; with a group of 10–30 fs + 4–6 hrs scutal setae (scts) on each side of scutum. Scutellum (scl) triangular; without oval membranous areas laterally; scl with 1–6 fs scutellar setae (scls). Mesopostnotum (pn 2) with a fairly narrow membranous area posterior to scutellum; mesopostnotal apophyses (pn 2 a) small or even possibly absent. Laterally: prealare (pra) elongate. Tegular (teg) large and sclerotised with a group of 20–30 fs 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) large: width of peritremes 100–125 m, each peritreme with a reticulated inner surface and each muscle plate strongly sclerotised. Ventrally: basisternum (stn 2) large, not nodulated, length 380–460 m, width 730–770 m; with a total of 35–50 hrs basisternal setae (stn 2 s); median ridge (mdr) absent; without a distinct marginal ridge (mr) anteriorly but ridge well developed anterolaterally between basisternum and lateropleurite (lpl); posteriorly with well­developed precoxal ridges (pcr 2); furca (f) moderately broad basally, with short arms, which diverge strongly; lateropleurite (lpl) large, approximately triangular, bounded ventrally by a broad marginal ridge, posteriorly by a broad precoxal ridge and laterally by a short, heavily sclerotised, subepisternal ridge (ser); each lpl without setae. Without postmesospiracular setae (pm 2 s). Wing sclerites: probably similar to other members of this group but most could not be identified; additional sclerite present.

Metathorax: dorsally: metapostnotum (pn 3) possibly unsclerotised, but with 0 or 1 fs metatergal setae (mts). Laterally: suspensorial sclerites (ss) well developed. Dorsospiracular setae (dss) absent. Pleural ridge (plr 3) well developed, extending from metacoxae to base of hamulohalteres (h); precoxal ridge (pcr 3) well developed and extending about 380 m ventrally towards metasternum; with a moderately deep pleural apophysis (pla 3). Metepisternum (eps 3) present as a sclerotisation on ventral side of metapleural ridge (plr 3), each with 3–9 fs postmetaspiracular setae (eps 3 s); metepimeron (epm 3) short and extending dorsally. Posterior spiracles (sp 3) large: width of peritremes about 120– 125 m. Ventrally: metasternum (stn 3) represented by a quadrate median sternite with 2 lateral arms; probably with well­developed lateral sternal apophyses (stn 3 a). Postmesoprecoxal ridge setae (ppcr 2 s) and anterior metasternal setae (amss) absent; posterior metasternal setae (pmss): total of 5 or 6 pairs of fs.

Wings: large and well developed; length 3.7 mm, width 1.95 mm (ratio of length to width 1:0.53; ratio of total­body length to wing length 1:0.90). Subcostal thickening (sclt) well developed; wing anterior to sclt only mildly sclerotised; rest of wing membranous, sometimes with faint reticulations; with a line of 10–14 circular sensoria (sens) along more distal part of subcostal thickening but alar setae (als) absent; radius (rad) and media (med) veins apparently represented by light sclerotisations; alar fold (af) not detected. Alar lobe (al) small and lightly sclerotised. Hamulohalteres (h) mainly sclerotised and quite broad, with a strong vein along anterior margin, which has a distinct indentation proximally; length 584–645 m, width uncertain; with 1 short apical hamulus (ham), about 24–34 m long, which broadens into a flat, plate­like apex.

Legs: all legs exceptionally strong and well developed, particularly all femur; prothoracic legs fossorial, markedly different from meso­ and metathoracic legs. Prothoracic legs as follows: lengths (m): coxae (cx) 535–680; trochanter (tr) + femur (fm) 695–900; tibia (ti) 175–205 and tarsus (ta) 85–110; with a group of 30–40 very small setae near coxal base (mainly on posterior surface) + about 30–40 fs distally; each coxa with a strong internal ridge; trochanter with about 15–20 fs but without a long flagellate seta; trochanter with a group of 6 or 7 campaniform sensilla (camp) on each lateral surface near coxal articulation; trochanterofemur articulation clear and diagonal; femur with about 130 fs; bifurcated setae (bs) and very short setae absent. Tibia, tarsus and claw all more or less fused and forming a paddle­like structure; tibia with 16–18 fs + 6 small setae; bifurcated setae (bs) and tibial spurs (tibs) absent; tarsus 1 segmented, with 1 (or perhaps 2) campaniform sensilla (camp) on proximal dorsal surface; without bifurcated setae (bs); with 7 or 8 fs + 4 or 5 very small setae; tarsal spurs (tabs) absent; tarsal digitules (tdgt) apparently absent; claws (c) broadly fused to base of tarsus, with no real articulation, length 250–315 m; each claw with 5 or 6 fs but with possibly no digitules (cdgt). Meso­ and metathoracic legs: lengths (m): coxae (cx) II 505–625; III 440–600 m; metacoxae with a group of 30–60 very small hs near base, plus 20–30 long fs distally. Trochanter (tr) + femur (fm): II 770–930; III 980–1210 m; metatrochanter with about 22 hs but without a long flagellate seta; trochanter with a group of 5 or 6 campaniform sensilla (camp) on each lateral surface near coxal articulation; trochanterofemur articulation clear and diagonal; metafemur with about 70–80 long fs along ventral and posterior margins, 15–20 shorter fs along dorsal and anterior margins plus about 14 short spinose setae along ventral margin; bifurcated setae (bs) absent. Tibia (ti) lengths: II 645–825; III 760–910; metatibiae with a line of strong spine­ or spur­like setae along ventral margin plus about 14 short spines; setae becoming similar to fs elsewhere, particularly along dorsal margin where they are long and very fleshy at base, including 4 or 5 shorter, stout, very blunt setae; bifurcated setae (bs) absent; each tibia with several tibial spurs (tibs) distally, longest about 65– 70 m. Tarsi (ta) 1­segmented; lengths: II 220–255; III 205–250 m; with 1 (perhaps 2?) campaniform sensilla (camp) on proximal dorsal surface; without bifurcated setae (bs); with 8 fs, 2 basiconic sensilla (bass) + 3 very short setae on ventral and lateral surfaces; dorsal surface with 6 very large, long fs + a total of about 8 short, blunt setae in 2 rows; tarsal spurs (tabs) not differentiated, but spur­like setae in this position 70–80 m long; tarsal digitules (tdgt) apparently absent or represented by largest and broadest blunt seta. Claws (c) digitate, with 3 fingers of approximately similar length; none with a denticle (cd); claw III about 107–120 m long, with 2 fine, acute digitules (cdgt), each about 40–50 m long; each claw broadly attached to tarsus.

Abdomen

Largely membranous, without caudal extensions. Tergites (at) on segments I and II quite large, very small or absent on II–V and narrow but wide on segments VI–VIII. Large sternites (as) present medially on segments II–VIII. Pleurites only present on segment VIII. Dorsal abdominal setae (ads) I–VII few, as follows (on each side): II 4–8 fs, III 3–7 fs, IV 3–6 fs, V 2–6 fs, VI & VII 0 or 1 fs (almost all hairs (hrs) on 1 specimen!). Ventral abdominal setae (avs) in lines of fs along posterior margins of all sternites as follows (totals): II 13–24 fs, III 15–26 fs, IV 15–21 fs, V 13–21 fs, VI 10–13 fs, VII 5–10 fs and VIII 1 or 2 fs. Pleural setae: dorsal pleural setae (dps) only present on segment VIII, with 3–6 on each pleurite; ventral pleural setae (vps) as follows: I–III 0; IV–VI 3–8 fs, VII 2–5 fs, VIII 1–5 fs. Pores absent. With a tightly packed group of membranous tubular ducts (tdc) present medially on segments VI and VII, groups fused to form a single oval area of ducts; outer opening of each duct roughly six­sided and each duct about 33 m long; size of both groups combined about 170–210 m long and 170–230 m wide. Abdominal spiracles (asp) clearly present on segments VI–VIII but trachea present laterally on more anterior segments; width of each peritreme 16– 18 m.

Genital segment: anus (an) presumably present on dorsal surface just anterior to penial sheath. Penial sheath (ps) strongly sclerotised and triangular in shape, about 380–470 m long and 345–390 m at widest point. Penial sheath more membranous ventrally, with a long ventral slit through which aedeagus emerges. Aedeagus (aed) quite broad when viewed from the side and roughly S­shaped; narrowly triangular when viewed dorsally, with a pointed apex and a fairly broad base; length 500–600 m, width at base when viewed dorsally 145–160 m; ventrally possibly articulating on a heavily sclerotised basal rod (bra). Eversible endophallus (eph) apparently absent. Penial sheath with some longer setae (pss) basally, each perhaps 40–60 m long; setae nearer apex all very short; also with a group of sensilla (psp) near apex.

Comment

In his phylogenetic analysis of the genera within the Margarodidae based on adult female characters, Vahedi (2002) found that D. tanganyicus was sister to Margarodes . It is clear from the descriptions of Margarodes species below and the description of M. vitium Giard by Theron (1958) (= M. vitis Philippi , but included in Sphaeraspis by Jakubski, 1965)) that the males of these two genera are also very similar.

Figures

FIGURE 8. Male Dimargarodes tanganyicus Jakubski. Letters as for Fig. 6 except F = fleshy body seta; N = side view of posterior end of abdomen, and K = minute seta as on scape and coxae.