Ripersiella sp. A

Hodgson, Chris, 2012, Comparison of the morphology of the adult males of the rhizoecine, phenacoccine and pseudococcine mealybugs (Hemiptera: Sternorrhyncha: Coccoidea), with the recognition of the family Rhizoecidae Williams 3291, Zootaxa 3291 (1), pp. 1-79 : 44-46

Ripersiella sp. A

( Fig. 14 )

Material examined. India, Calcutta , 5.i.1980, grass ( Poaceae ), Gy. Topá ( PPIHH): 1/ 1♂ (fair-good condition) .

Mounted material: apterous; very small, total body length about 492 µm, greatest width 224 µm; antennae 6 or 7 segmented, short, much less than half total body length; most flagellar segments slightly shorter than wide, possibly with only hair-like setae (hs); body fairly hirsute, all hs, variable in length but longer on dorsum (about 16–24 µm) than on venter (13–17 µm); loculate pores (lp) frequent, most abundant on dorsum, each about 5 µm wide with 4 or 5 loculi; simple pores absent. Without either ocelli or simple eyes; tarsi (ta) 1 segmented; trochanter (tr) with probably 2 pairs of campaniform pores.

Head: dorsal epicranium apparently unsclerotised; with about 13–15 pairs of hs dorsal head setae (dhs) + 2 or 3 pairs of loculate pores (lp) distributed along full length of head; simple pores absent. Simple eyes and ocelli both absent. Ocular sclerite not apparently differentiated. Ventral epicranium also apparently unsclerotised, without any sign of ventral midcranial ridge or lateral arms of midcranial ridge; with 1 pair of ventral midcranial ridge setae (vmcrs). Preocular ridge (procr) absent dorsally but procr represented ventrally by a thin ridge which extends medially from each antenna and possibly fuses medially.

Antennae: 6 or 7 segmented (when 6 segmented, segments III and IV clearly fused, see Figure); length about 107 µm (ratio of total body length to antennal length 1:0.22). Scape (scp): 31–33 µm long, 39 µm wide, with 4 hs. Pedicel (pdc): 26 µm long, 25 µm wide; with 2 hs + a small campaniform pore. Segments III–VII all about 25 µm wide; mostly slightly wider than long, with narrow intersegmental membranes; lengths of segments (µm) III–VI 18–23, VII 39–40; hs each 26–32 µm long, mainly in whorls; approximate number of hs per segment: III 3; IV 5 hs; V & VI 5–7 + 1 antennal bristle (ab), and VII 7 hs + 3 longer and 2 shorter ab.

Thorax. Prothorax: not swollen laterally; dorsally with a few hs and lp distributed in a narrow band across segment, pores also in a group near margin. Sternum (stn 1) with 1 pair hs + 1 pair lp in position of prosternal setae (st 1 s); anteprosternal setae and antemesospiracular setae probably absent.

Mesothorax: unsclerotised. Dorsum with two narrow bands of hs, anterior band with a few lp medially, posterior band with a small group of lp near margin; ventrally with a few setae and an lp near each mesothoracic spiracle. Mesothoracic spiracle (sp 2): width of peritreme about 18 µm, with a single lp laterally.

Metathorax: dorsally with a narrow band of hs extending across full width of segment, representing metatergal setae (mts) and dorsospiracular setae (dss) and with a group of lp near margin. Metapleural ridge without either a metaprecoxal ridge or an additional short ridge extending ventrally from near coxal articulation. Metepimeron absent. Metathoracic spiracle (sp 3): width of peritreme about 20 µm; each with 1 lp. Metasternum (stn 3) with a pair of setae + an lp anterior to each metacoxa.

Wings and hamulohalteres (h) absent.

Legs: metathoracic legs longest. Coxae (cx): I 73; II 71; III 72 µm long; coxa III with about 6 hs. Trochanter (tr) + femur (fm): I 116; II 116; III 126 µm long; trochanter III with about 5 hs; each trochanter probably with 2 roundly oval sensoria in a line parallel to trochanterofemur articulation, but without strong Y-shaped sclerotised ridges; long trochanter seta not differentiated but seta in this position about 15–17 µm long; femur III with about 7 hs. Tibia (ti): I 75; II 75; III 95 µm long; tibia III each with 6 setae, all tibiae with 2 apical spurs (tibs); length of III 18–20 µm. Tarsi (ta) 1 segmented; lengths: I 50; II 50; III 58 µm (ratio of length of tibia III to length of tarsus III 1:0.61); tarsus III with 4 setae, most distal ventral seta spur-like, about 15 µm long; tarsal digitules (tdgt) setose, very short, each 3–4 µm long. Claws (c) long and narrow, without a denticle; length: III 28–30 µm; claw digitules (cdt) exceptionally short, setose.

Abdomen: segments I–VIII: tergites (at) and sternites (as) unsclerotised, except tergite on VIII which mildly sclerotised; pleural areas unsclerotised. Loculate pores (lp) few ventrally, restricted to 1 medially on II and 1–3 near margin on II–VI; dorsally, lp present mainly in a line with dorsal setae (ads) on all abdominal segments. Setae on I–VII: dorsal setae (ads) each 17–24 µm long, present in a single line of about 8–12 across each segment, ventral setae (avs) more setose and shorter than ads (each 13–17 µm long), with 4–6 avs across each segment; division into dorsal (dps) and ventral pleural setae (vps) not clear, but probably with 2 long dps and 1 shorter avs. Each caudal extension on segment VIII rounded, with 3 much longer and more robust setae, each about 66–85 µm long; tergite VIII with 3 pairs of large hs ads medially + a pair of lp laterally on each side; sternite without setae or pores.

Genital segment: penial sheath (ps) not extending anteriorly into segment VIII; with a dorsal, finger-like ridge which narrows posteriorly to a point, and with a broad slit-like opening ventrally; length from anterior margin to apex 96 µm, width 93 µm at widest point; finger-like dorsal ridge about 40 µm wide. Dorsal ridge with a wide triangular anus anteriorly (width about 30 µm) + with 3 longish setae on each side, each about 18 µm long. Ventrally, aedeagus (aed) emerges through ventral opening; borders of opening not apparently sclerotised, each border with 4 rather short setae, each about 3–7 µm long. Aedeagus (aed) strongly curved, perhaps 66 µm long, apex not bifid; anteriorly, aedeagus bends and fuses with a short sclerotised basal rod (bra). A few sensory sensilla present on apex of penial sheath.

Comment. The adult male of Ripersiella species A is somewhat similar to that of Ri. kondonis and Ri. malschae in lacking: (i) simple eyes and ocelli, and in having (ii) 7-segmented antennae, (iii) loculate pores present more or less throughout, and (iv) only a single tarsal segment. However, it differs in having (character states on Ri. kondonis in brackets when appropriate): (i) much shorter setae on the antennae and body; (ii) fleshy setae not differentiated from hair-like setae (differentiated); (iii) more loculate pores, particularly medially on dorsum of abdomen and near margin; (iv) aedeagus not bifid at apex (bifid), (v) the shape of the flagellar antennal segments, each more or less parallel-side and broadly connected (almost round and narrowly connected), and (vi) absence of fleshy setae on most flagellar segments (present). Nonetheless, it is here considered that these two species are probably closely related.

Figures

FIGURE 14. Ripersiella sp. A. Adult male. Where C = loculate pore and K = distal end of posterior leg. For other labels, see under Materials and methods: conventions.