Aclerda tillandsiae Howell, 1972

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 : 205-208

Aclerda tillandsiae Howell ( Fig. 80 )

Aclerda tillandsiae Howell 1972, 1262 . Type data: USA, Georgia, Lowndes County, Valdosta , on Tillandsia usneoides . Holotype, female, by original designation. Type depository: USNM.

Material examined. USA, Georgia, Valdosta, Lowndes Co., on Tillandsia usneoides (Bromeliaceae) , 4.xi.1971, H.H. Tippins ( USNM): 1/1ad ♂ (unstained, in good condition but missing one antenna and both wings).

Note: details in […] brackets refer to the data in Howell, 1976.

Mounted material: total body length 1.6 (1.24–1.51) mm; width across triangular plates of mesothorax 286 mm; slender with very few setae; antennae approximately half body length.

Head: approximately diamond-shaped in dorsal view; length 166 [174–199] μm; width across genae 203 [202– 227] μm. Median crest (mc) probably not reticulated but with transverse striations; extending posteriorly to about level with dorsal simple eyes; with 1 [1 or 2] hs dorsal head seta (dhs) on each side. Dorsal mid-cranial ridge absent; ventral mid-cranial ridge (vmcr) quite long, extending from lateral arms anteriorly to ocular sclerite posteriorly; with a narrow, slightly reticulated border anteriorly, which broadens posteriorly and fuses with ocular sclerite; with 0 or 1 hs ventral mid-cranial ridge setae (vmcrs) on each side. Genae: genal setae (gs): 0 or 1 [absent] hs on each side. Eyes: two pairs of simple eyes: dorsal more or less round, 30 [28–42] μm wide, ventral oval, 31 x 40 [34–42] μm wide. Ocelli (o) hard to see but considered to be present laterally [absent]. Ocular sclerite (ocs): polygonally reticulated, each reticulation without inner microridges. Preocular ridge very short or absent ventrally, perhaps extending dorsally from each scape towards dorsal eyes. Postocular ridge (pocr) of moderate length, extending past each ocellus, possibly reaching dorsal eye; not heavily sclerotised. Dorsal ocular setae (docs) absent. Ventral head setae (vhs): 5 [3–6] hs on each side almost in a transverse line, with median setae almost between ventral eyes and lateral setae near margin. Cranial apophysis (ca) possibly 81 μm long anterior to tentorial bridge; possibly trifur- cated.

Antennae: total length 711 [700–862] μm long (ratio of total body length to antennal length 1:0.68). Scape (scp): 30–33 μm long, 42 μm wide. Pedicel (pdc): length 33–35 μm, width 31–35 μm; with 1 hs on ventral surface and 2 hs dorsally (no sensilla placodeum detected). Segments III–X each 13–19 [14–20] μm wide: fs each 19–25 μm long; lengths of segments (μm): III 108; IV 110; V 108; VI 85; VII 81; VIII 51 and IX 50; setae rather few, ap- proximate number per segment: III 1 fs + 2 hs (no sensilla basiconica seen); IV 7 + 0 hs; V 16 fs + 0 hs; VI 11 fs + 0 hs; VII 14 fs + 0 hs; VIII 6? fs + 0 hs; IX 10 fs + 0 hs. Segment X 69 [50–73] μm long but distorted, with 16 [15] fs + 3 capitate setae; bristles not apparently differentiated.

Thorax. Prothorax: pronotal ridge (prnr) considered to be fused medially [not fused]; pronotal sclerite (prn) probably present but narrow. Pronotal setae (stn 1 s), medial pronotal setae and post-tergital setae absent. Post-tergites (pt) possibly present [absent]. Prosternum (stn 1): possibly unsclerotised but with a weak [well-developed] transverse ridge; without reticulations and without prosternal setae (stn 1 s). Anteprosternal (astn 1 s) and antemesospiracular setae (am 2 s) absent.

Mesothorax: prescutum (prsc) 145 μm wide, 83 μm long, without a medial ridge [medial ridges present – but see under Comment below]; prescutal ridges (pscr) and prescutal suture (pscs) well developed; without prescutal setae (prscs). Scutum (sct): median membranous area 91 [70–109] μm wide, 30 [17–28] μm long, bounded laterally by a strongly sclerotised margin; membrabnous area with 2 pairs of scutal setae (scts); lateral areas of scutum reticulated laterad to scutellum [not reticulated but see discussion]. Scutellum (scl) 124 [120–146] μm wide, 37 [36–42] μm long; no foramen visible [present] but with 1 pair small hs scutellar setae medially. Mesopostnotum (pn 2): area bounded laterally by mesopostnotum and anteriorly by scutellum possibly without a large sclerite [not mentioned]. Basisternum (stn 2) about 178 [154–182] μm wide, 124 [109–135] μm long; with a weak median ridge (mdr) present medially but more or less absent at each end; bounded anteriorly by a weak marginal ridge (mr) and posteriorly by a strong precoxal ridge (pcr 2); without basisternal setae (stn 2 s); lateropleurite very broad, with a weak extension from marginal ridge, without reticulations [reticulations present but see under Comment below]; furca (f) well developed, broad basally, arms more or less parallel and quite short. Postalare (pa) not reticulated anteriorly; without postalare setae (pas). Mesothoracic spiracle (sp 2): peritreme 22 μm wide, each with 1 [1–3] disc-pore. Tegula (teg) with about 3 [3–5] hs tegular setae (tegs).

Metathorax: with 1 pair of metatergal setae (mts). Dorsospiracular setae (dss) absent. Dorsal part of metapleural ridge (plr 3) absent; ventral part of metapleural ridge not well developed; metepisternum (eps 3) with 3 or 4 hs postmetaspiracular setae (eps 3 s) on each side. Metepimeron present without setae. Antemetaspiracular setae (am 3 s) absent. Metathoracic spiracle (sp 3) positioned posterior to mesocoxae: width of peritreme 21–23 μm; with 1 [0–3] disc-pores. Postnotal apophysis (pna) represented by a narrow slit between meso- (pn 2) and metapostnotum (pn 3). Metasternum: condition uncertain [faintly reticulate, without setae]. Anterior (amss) and posterior metasternal setae (pmss) absent.

Wings: details unknown [hyaline, 1086–1394 μm long; 330–403 μm broad at widest point; width: length ratio ca. 1:0.3. Alar setae absent. Hamulohalteres absent].

Legs: prothoracic legs slightly longer than other legs. Coxae (cx): I 82–92; II 78–83; III 74–79 μm long; coxa III with about 5 hs, length of long coxal seta unknown. Trochanter (tr) + femur (fm): I 173–182; II 178; III 161–166 μm long; trochanter III with 3 hs; long trochanter seta 25 μm long, flagellate; femur III with about 2 fs + 11 hs. Tibia (ti): I 211–216; II 202–207; III 180–182 μm; tibia III with a total of about 18 setae, becoming spur-like on distal third of leg; tibio-tarsal articulation absent; apical spur (tibs): length (III) 22 μm. Tarsi (ta): I 124; II 115–120; III 99–104 μm long (ratio of length of tibia III to tarsus III 1:0.56); tarsus III with 16 setae, mostly spur-like; tarsal spurs (tabs) 25 μm long, barely differentiated. Claws (c) rather elongate and narrow; without a denticle; length (III) 26 μm, much longer than width of tarsus.

Abdomen: sclerotisation of tergites (at) and sternites (as) unclear but probably with both lightly sclerotised on all segments; pleurites (ap) probably sclerotised only on segments V–VII [absent]. Dorsal abdominal setae (ads) (totals): segments I–VI each with 2 (2 or 3) hs + 1 small convex pore (cp) [pores not mentioned by Howell]; VII 0 or 1 hs. Pleural setae: (on each side): dorsopleural setae (dps): II & III possibly absent; IV–VI each with 2 or 3 (5) hs + 0 or 1 cp; ventropleural setae (vps) II 0 hs; III–VII each with 1 (1 or 2) hs. Ventral abdominal setae (avs): II 0–2 hs; III & IV each with 1 or 2 hs; V–VII each with 4 hs. Caudal extensions on segment VII absent.

Segment VIII strongly sclerotised, quite long, 60 μm wide, 58 μm long with sclerotised lateral ridges; caudal extension short and rounded, with 1 pleural seta 37 μm long (42–115 μm) + 2 or 3 shorter hs setae. With a distinct constriction between segment VIII and penial sheath.

Genital segments: penial sheath (ps) articulating anteriorly with sternite of segment VIII; total length 171 μm, including sclerotised part of segment VIII (ratio of total body length to penial sheath length 1:0.14); length of penial sheath without sternite VIII 113 μm, width at base of segment VIII 40 μm. Anus (an) surrounded by a sclerotised ring. Style narrowing along entire length to a sharper apex than on other species studied here. Basal rod (bra) short, 28 μm long, becoming spindly anteriorly. Aedeagus (aed): length uncertain, perhaps 44–47 μm long, probably pointed (ratio of aedeagus length to basal rod length 1:0.62). Membranous ‘endophallus’ absent.

Comment. This description differs from that of Howell (1976) in a number of ways (Howell’s views in […] brackets): (i) it is here considered that ocelli are present on the lateral margins but hard to see [ocelli absent]; (ii) pronotal ridge probably not interrupted [interrupted]; (iii) possible absence of lateral pronotal sclerites [present]; (iv) no setae present anterior to pronotal ridge [present]; (v) prescutum not divided into two halves [divided] (longitudinal ridges are present but these commonly appear when the prescutum and scutellum are flattened as these two structures can be highly convex and this is considered to have occurred here); (vi) lateral margins of scutum reticulated laterad to scutellum [not mentioned but see (viii) below]; (vii) scutellum without a small foramen [present, but he fails to mention the pair of small setae which are present medially]; (viii) lateropleurite not reticulated [reticulated but could have been mistaken for reticulation on scutum]; (ix) metepimeron quite well developed [greatly reduced], and (x) pleurites probably present on segments V, VI and VII [absent]. In addition, Howell (1976) does not mention the small convex pores which are present on the dorsum of the abdomen.

The adult male of A. tillandsiae is extremely similar to the other five species described here apart from the structure of the style and aedeagus; the latter appears to be narrower than segment IX (broader than the penial sheath in the other species). A. tillandsiae also appears to differ in (possibly) the absence of a sclerotised plate on the membranous area within mesopostnotum (this could be present but the lack of staining made this impossible to detect).

Figures

FIGURE 80. Aclerda tillandsiae Howell. Macropterous male. (Aclerdidae, Aclerdinae).