Furcaspis costulariae, Hardy, Nate B. & Williams, Douglas J., 2018

Hardy, Nate B. & Williams, Douglas J., 2018, Doubling the known endemic species diversity of New Caledonian armored scale insects (Hemiptera, Diaspididae), ZooKeys 782, pp. 11-47 : 11

Furcaspis costulariae sp. n. Figure 6

Material examined.

Holotype: New Caledonia: 1 adult female (1.46 mm long, 1.23 mm wide): ex Lophoschoenus sp. [current valid name is Costularia chamaedendron ], Mont d’Or, roadside fountain, 24.viii.1963, SW Brown, SWB accession 258 (USNM). Paratype: New Caledonia: 1 second-instar nymph, same data as holotype, SWB accession 258 (USNM).

Description.

Adult female, n = 1. Presumed to secrete scale cover. Body of holotype 1.46 mm long, broadest at mesothorax (1.23 mm); body outline turbinate (margin of head and thorax almost circular, abdomen tapering to truncate pygidium), margin of pre-pygidial abdominal segments slightly convex. Cuticle sclerotized (or at least heavily stained).

Pygidium wider than long, with three lobes on each side. Median lobes longer than wide, each with rounded apex, separated by ~2.5 × their width. L2 and L3 as long as median lobe but broader, with more truncate apex. Pygidial margin anterior to L3 with a few long setae (up to 65 μm) and several tooth-like projections, pointed or truncate, smaller than lobes; posterior terminus of pygidium heavily sclerotized, distinct paraphyses not discerned. Plates each bifid, longer than lobes; two between median lobes, two between L1 and L2, 3 between L2 and L3, two anterior of L3. Anus in anterior third of pygidium, obstructed by detritus under cover-slip of slide mount. Thin one-barred macroducts abundant along posterior margin, ~18 on each side away from margin, some anterior of anus. Venter of pygidium with vulva in anterior half. Perivulvar pores absent.

Pre-pygidial segments. Dorsum with fine, hair-like setae along margin and submargin. Eye a subcircular disk on dorsal submargin lateral of antenna. Microducts scattered across head and thorax, along submarginal and submedial parts of abdominal segments grading into one-barred macroducts along margin of posterior pre-pygidial segments. On venter, microducts in loose transverse bands from submedian to margin of mesothorax and metathorax, posterior to each spiracle, also scattered along abdominal margin and submargin. Patches of gland tubercles on prothorax and mesothorax, 23-26 on each side of body, most on prothorax. Abdominal segments each with a small submedial seta with proportionately large, sclerotized collar, forming longitudinal rows from near lateral edge of vulva to posterior spiracles. Antennae each with four long setae. Anterior spiracle with cluster of nine quinquelocular pores. Posterior spiracle without pores.

Comments.

For a synthetic treatment of the genus Furcaspis , see the revision of Williams et al. (2006). Paraphrasing their diagnosis, adult females of Furcaspis have (1) simple bifurcate (rarely trifurcate) pygidial plates; (2) 3 pairs of notchless plates; (3) the antenna with multiple setae; (4) thin macroducts; (5) paraphyses; and (6) pores absent from the posterior spiracles. Currently, 29 species are recognized, two of which are endemic to New Caledonia: F. cyphokantiae Williams & Miller and F. matileae Williams & Miller. The adult female of F. cyphokantiae differs from that of F. matileae by having (1) gland tubercles on the venter of the mesothorax; (2) sclerotized lateral areas on the thorax; and (3) medial lobes that are closer together, and more similar in size and shape to the other lobes on the pygidium. The adult female of F. costulariae can be distinguished by having (1) only four long setae on the antenna (5-8, but usually six in F. cyphokantiae and F. matileae ); (2) 23-26 gland tubercles, with only 2-3 on the mesothorax (tubercles absent from meso thorax, of M. matileae , and total 36-40 in M. constulariae ); (3) uniformly sclerotic cuticle, and (4) lacking discernible paraphyses, although they may simply be impossible to detect against the background of sclerotic cuticle on the pygidial margin. All three New Caledonian species feed on monocotyledons; F. cyphokantiae and F. costulariae feed on sedges ( Cyperaceae ). It is possible that these three species are, in fact, just host-induced phenotypic variants of one New Caledonian metapopulation. Our decision to name the female from Costularia formalizes the alternative hypothesis that each host-associated form is a good species.

Etymology.

The species epithet is taken from the genus name of the host, a sedge that is endemic to New Caledonia.