Tachardiella, Cockerell, 1901

Hodgson, Chris, 2020, A review of neococcid scale insects (Hemiptera: Sternorrhyncha: Coccomorpha) based on the morphology of the adult males, Zootaxa 4765 (1), pp. 1-264: 166-169

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http://doi.org/ 10.11646/zootaxa.4765.1.1

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Tachardiella   sp. ( Fig. 66 View FIGURE 66 )

Material examined: Mexico, Tampico, host unknown, 8.vii.’91, D. Riley ( USNM, ex Brownsville 27512; 95- 06955): 1/1ad ♂ (in fair condition, but prothorax badly damaged).

Mounted material: moderate-sized, total body length about 1.39 mm; robust; antennae quite long; body not particularly hirsute, but fleshy setae (fs) fairly frequent ventrally on abdomen, these generally easily differentiated from hair-like setae (hs); length of fs on antennae more than width of antennal segments. Wings about 2/3 total body length and a little more than half as wide as long.

Head: appearing rather rounded in dorsal view on mounted specimen; in side view, probably with ventral eyes on a postero-ventral protuberance; width across genae 219 μm. Median crest (mc) elongate, with a few longitudinal striations (no reticulations); posteriorly fusing with a large, heavily sclerotised, X-shaped postoccipital ridge (por); with 3 hs dorsal head setae (dhs) on each side. Mid-cranial ridge: ventral ridge (vmcr) quite well developed, extend- ing about half-way to ocular sclerite posteriorly and with well-developed lateral arms (lmcr); with a narrow, striated border anteriorly which quickly broadens posteriorly, fusing with ocular sclerite (ocs); with 0 or 1 fs + 0 or 1 hs ventral mid-cranial ridge setae (vmcrs) anterior to ocular sclerite. Genae (g) without polygonal reticulations; genal setae (gs) absent. Eyes: with two pairs of round simple eyes; dorsal eyes (dse) 70–75 μm wide, ventral eyes (vse) smaller, 60 μm wide. Ocelli (o) quite large, oval, 23 μm “long”, placed just postero-laterally to dorsal simple eyes. Ocular sclerite (ocs) sclerotised and lightly striated, particularly around both pairs of eyes, becoming reticulated just posterior to dorsal eyes. Preocular ridge (procr) with ventral arm long, extending about half-way over top of each ventral simple eye. Postocular ridge (pocr) strongly developed, extending dorsally past each ocellus, almost reaching postoccipital ridge; with a small extension up dorsal margin of each ocellus. Dorsal ocular setae (docs) absent; ventral head setae (vhs) present between ventral eyes and also just anterior to them: with 8–12 fs + 0–2 hs on each side; without setae posterior to ventral eyes. Preoral ridge (pror) possibly not well developed. Cranial apophysis (ca) possibly short but rather unclear.

Antennae: 10-segmented and filiform, 794 μm long (ratio of total body length to antennal length 1:0.57). Scape (scp): 41–43 μm long, 46–48 μm wide, with 1 fs on ventral surface and 2 fs on dorsal surface. Pedicel (pdc): length 53 μm, width 43 μm; with a few concentric ridges; with 14 fs + 0–2 hs. Segments III–X all 17–22 μm wide; fs 30–32 μm long; lengths of segments (μm): III 106–113; IV 91; V 101–108; VI 101–103; VII 86–90; VIII 76–78 and IX 74–76; approximate number of setae per segment: III 20–23 fs + 0 hs + 1 sensilla basiconica; IV 14–16 fs + 0 hs; V 24 fs + 0 hs; VI 27–29 fs + 0 hs; VII 21 fs + 0 hs; VIII 11–17 fs + 0 hs + 1 bristle; IX 15–17 fs + 0 hs + 1 bristle. Segment X 91 μm long; not constricted apically but apex rather pointed, with two setae; possibly without capitate setae but with 18–21 fs + 1 sensilla basiconica (sb); bristles not apparently differentiated.

Thorax. Prothorax (badly damaged): pronotal ridge (prnr) possibly poorly developed, not fused dorsally; lateral pronotal sclerite (prn), if present, narrow and without lateral pronotal (lpns) setae. Medial pronotal setae, post-tergites and post-tergital setae absent. Sternum (stn 1) apparently rather small and possibly located far anteriorly between procoxae, mildly sclerotised, with a weak transverse ridge; median ridge absent; without prosternal setae (stn 1 s). Anteprosternal (astn 1 s) and antemesospiracular setae (am 2 s) absent.

Mesothorax: prescutum (prsc) rather oval in shape, 75 μm long, 137 μm wide; prescutal ridges (pscr) and pres- cutal suture (pscs) well developed. Scutum (sct): median membranous area present, 149 μm wide, 53 μm long; scutal setae (scts) absent; lateral margins sclerotised but not reticulated. Scutellum (scl) 166 μm wide, 46 μm long; prob- ably highly convex and tubular; foramen possibly absent; with 2 small hs scutellar setae (scls). Basisternum (stn 2) 248 μm wide, 79 μm long; without any signs of a median ridge (mdr), but bounded anteriorly by a strong marginal ridge (mr) and posteriorly by strong precoxal ridges (pcr 2); basisternal setae (stn 2 s) absent; lateropleurite (lpl) large but not reticulated, with a strong extension from marginal ridge anteriorly; furca (f) well developed, narrow-waisted, arms very divergent and extending anteriorly to marginal ridge. Mesopostnotum (pn 2) and postnotal apophysis (pna) well developed.Area bounded anteriorly by scutellum and laterally and posteriorly by mesopostnotum not sclerotised. Mesepisternum (eps 2) not reticulated; subepisternal ridge (ser) well developed. Postalare (pa) not reticulated anteriorly; without postalare setae (pas). Mesothoracic spiracle (sp 2): peritreme 36–38 μm wide. Postmesospiracular setae (pm 2 s) apparently absent. Tegula (teg): well developed, with 3 or 4 tegular setae (tegs) on each side.

Metathorax: with 1 (possibly 2) pairs metatergal setae (mts). Dorsospiracular setae (dss) absent. Dorsal part of metapleural ridge (plr 3) absent; ventral part well developed; episternum (eps 3) strongly sclerotised anteriorly, but postmetaspiracular setae (eps 3 s) absent. Metepimeron (epm 3) sclerotised but without setae. Antemetaspiracular setae (am 3 s) absent. Metathoracic spiracle (sp 3): width of peritreme 31–33 μm. Metasternum (stn 3) membranous throughout. Anterior metasternal setae (amss) and posterior metasternal setae (pmss) absent.

Wings: hyaline, 825 μm long and 463 μm wide (ratio of length to width 1:0.56; ratio of total body length to wing length 1:0.59); alar lobe (al) and alar setae (als) absent. Wing sclerites apparently normal. Hamulohalteres absent.

Legs: legs subequal in length. Coxae (cx): I 95–99; II 120; III 103–108 μm long; setae of coxa III: 27 fs + 3 hs; long apical setae on each coxa 46–50 μm long. Trochanter (tr) + femur (fm): I 223–228; II 207–211; III 215–224 μm long; trochanter III with about 9 fs + 3 hs; long trochanter seta up to 69–75 μm; femur III with about 27 fs + 11 hs. Tibia (ti): I 173–187; II 195–199; III 207–211 μm; tibia III with a total of about 49 setae, mainly fs and hs, a few becoming spur-like on distal third of leg; with two large apical spurs (tibs), length 21–25 μm. Tarsi (ta): I 128–135; II 149; III 149–154 μm long (ratio of length of tibia III to tarsus III 1:0.72); tarsus III with about 38 setae, some spur-like; possibly with 2 tarsal spurs, each only slightly differentiated, 25–27 μm; presence of tarsal campaniform pore uncertain; tarsal digitules (tdt) significantly shorter than claw. Claws (c) quite long and thin, rather longer than width of tarsi, slightly curved, with a strong denticle; length: III 26–28 μm; claw digitules (cdt) slightly longer than claw.

Abdomen: segments I–VII: tergites (at) unsclerotised; sternites (as) of segments VI and VII lightly sclerotised. Caudal extension (ce) of segment VII absent. Dorsal setae (ads) (totals): segments I 2 hs; II–VII setae absent. Pleural setae: dorsopleural setae (dps): II and III setae absent; IV–VII each with 1 or 2 hs on each side; ventropleural setae (vps): II–VII setae absent. Ventral setae (avs) (totals): II 9 fs + 2 hs; III & IV each with 15 fs + 2 or 3 hs; V & VI each with 16–18 fs + 4 or 5 hs; VII 12 fs + 2 hs.

Segment VIII: tergite (at) unsclerotised, with no ante-anal setae (aas); sternite (as) forming a strongly sclero- tised rectangular plate, without ventral abdominal setae (avs); caudal extension (ce) rounded, with about 5 fs + 3 hs dorsal pleural setae (one quite long, with a slightly clavate apex) + 2 fs ventropleural setae. Glandular pouches (gp) present, each rather narrow and elongate, with rather few disc-pores; setae of glandular pouch (gls) each 186–207 μm long.

Genital segments: penial sheath (segment IX + style) length 347 μm from base of sternite VIII (ratio of total body length to penial sheath length 1:0.25); 91 μm wide at anterior end of segment IX. Segment IX bulbous, with a strongly sclerotised border surrounding a large basal membranous area (bma), divided by a short, broad basal rod (bra) into two lateral areas, each lateral membranous area with 0 or 1 long setose seta; posterior sclerotised margin to basal membranous area with 2 or 3 long setae on each side. Style 29 μm wide at anterior end, tapering to a fine apex. Basal rod short, extending 25 μm anterior to aedeagus, fading rapidly within aedeagus; anteriorly not nearly reaching sternite of segment VIII. Aedeagus (aed) long and slowly tapering, 303 μm long (ratio of aedeagus length to anterior part of basal rod length 1:0.08); apex almost at tip of penial sheath. Style with 7 minute setae down each margin, and with a cluster of small sensilla present near apex.

Comment. The males of Tachardiella   sp. differed from those of T. aurantiaca   in having: (i) many more ventral head setae; (ii) almost complete absence of reticulations on ocular sclerite; (iii) absence of reticulations laterally on scutum; (iv) absence of reticulations on lateropleurite; (v) absence of basisternal setae; (vi) absence of dorsal part of mesopleural ridge; (vii) absence of alar lobes; (viii) absence of alar setae; (ix) sclerotisation reduced along anterior margin abdominal segment IX, and (x) many more dorsopleural setae on abdominal segment VIII.


Smithsonian Institution, National Museum of Natural History