Orthoneolepta, Hazmi & Wagner, 2013

Hazmi, Izfa Riza & Wagner, Thomas, 2013, Revision Of Neolepta Jacoby, 1884 And Related Galerucines From The Oriental Region, Including Descriptions Of Two New Genera (Coleoptera: Chrysomelidae: Galerucinae), Raffles Bulletin of Zoology 61 (1), pp. 73-95 : 74-77

REDESCRIPTION OF NEOLEPTA JACOBY, 1884

Type species. — Neolepta biplagiata Jacoby, 1884: 223 ; designated by Maulik (1936).

Total length. — 4.85–5.75 mm (mean: 5.23 mm)

Head. — Reddish-brown. Impunctate, with significant transverse impression between posterior third of eyes. Eyes large, strongly convex. Labial palpi slender and maxillary palpi enlarged ( Fig. 1a ), occasionally dark brown to black. Labrum and mandible brown to red. Antennae elongated, extended to the apical third of elytra ( Figs. 2 , 10 ); third to terminal antennomere densely covered by bristle-like setae. First and second basal antennomere contrasting reddish-brown, third to terminal antennomere black. First antennomere club-shaped, second antennomere a bit shorter than third antennomere; ratio length of second to third antennomeres 0.75–0.80 (mean: 0.76); ratio length of third to fourth antennomeres 0.40–0.50 (mean: 0.44); the median antennomeres insignificantly widened in N. sumatrensis but rather slender in N. quadriplagiata .

Thorax. — Pronotum transverse, anterior angle rounded and slightly thickened, posterior margin rounded, sinuate at each side ( Figs. 2 , 10 ). Reddish-brown as head, shiny and finely punctuated with a transverse depression beyond the middle of the base. Pronotal width 1.50–1.75 mm (mean: 1.62 mm), ratio length to width 0.52–0.60 (mean: 0.56). Scutellum triangular, impunctate, reddish-brown. Procoxal cavities nearly closed ( Fig. 1b ). Meso- and metathorax brown to red. Metasternum broad ( Fig. 1c ). Elytra finely punctuated, black with transverse yellowish spot on the disc of each elytron, two spots on N. sumatrensis ( Fig. 2 ) and four spots on N. quadriplagiata ( Fig. 10 ). Elytral length 3.80–4.50 mm (mean: 4.15 mm), maximal width of both elytra together 2.00– 3.30 mm (mean: 2.93 mm), ratio of maximal width of both elytra together to length of elytra 0.69–0.76 (mean: 0.72). Alae fully developed ( Fig. 1d ). Legs long and slender, basi-metatarsus elongated ( Fig. 1 e–g), entirely reddish-brown, black tibia and tarsus in N. quadriplagiata .

Abdomen. — Pale yellow to reddish-brown. Last visible sternite in females rounded at apex ( Fig. 1h ) and in males with two deep, parallel-sided incisions ( Fig. 1i ).

Male genitalia. — The median lobe is symmetrical, parallelsided at base and insignificantly narrowed towards apex. Apically not incised and carinated ventrally ( Figs. 4a, b , 12a, b ). Tectum long, broad to narrow and became pointed at apex, and reaching the tip of the median lobe ( Figs 4a, b , 12a, b .). Endophallus consist of a bundle of long, slender and straight median spiculae. A stronger sclerotized ventral carina with an apical hook close to the apex occurred on the apical third of the median lobe. Median lobe curved in lateral view ( Fig. 4b ). Sacculus clearly visible ( Figs. 4 , 12 ).

Female genitalia. — Spermatheca with small nodulus, and usually strongly curved, slender cornu ( Figs. 5 , 13 ). Two pairs of bursa sclerites, weakly sclerotized with strong spines ( Figs. 6 , 14 ).

Distribution. — The species of this group are restricted to South-East Asia and they are up to now only recorded from Singapore, Malaysia (Peninsular) and Indonesia (Borneo, Sumatra), southwards to Java ( Fig. 7 ).

Diagnosis. — Neolepta are medium size galerucines (4.85– 5.75 mm) with strongly elongated basi-metatarsus, reddishbrown head and pronotum, and usually contrasting black antennae. The elytral colouration is often with transverse yellowish spots ( Figs. 2 , 10 ). Neolepta is most similar to Arcastes Baly, 1865 with the type species, N. biplagiata Jacoby, 1884 looking very similar to A. biplagiata Baly, 1865 at a first glance. The similarities of certain morphological characters between these two groups have been reported in the revision of Arcastes (Hazmi & Wagner, 2010a) .

The pronotum of Neolepta is on average less broad (0.52–

0.60) than in Arcastes (0.48–0.57; Hazmi & Wagner, 2010a) and Candezea (0.42–0.59; Wagner & Kurtscheid, 2005), but in the same range as Monolepta (e. g., Wagner, 2007) of which these three genera are also listed in the “Monoleptites”. The significant widened third to eighth antennomeres are characteristic for all species of Arcastes , but in Neolepta , the antennae are slender and only N. sumatrensis has insignificantly widened median antennomeres.

The second antennomere is slightly shorter than the third in Neolepta (ratio length of second to third antennomeres 0.75–0.80), about the same range as in Monolepta (0.82–1.10) but very different to Arcastes (0.50–0.57) and Candezea (0.49–0.63) of which third antennomere is roughly twice as long as the second.

The median lobe are without incisions in these four genera, symmetrically arranged in Neolepta , Monolepta and Candezea but asymmetrically arranged in Arcastes with a certain shape of endophallic spiculae. In Neolepta , only the median spiculae occurred, while in Monolepta and Candezea three distinct pairs of spiculae occurred (median, ventral and lateral spiculae). In Neolepta , the stronger sclerotized ventral spur with an apical hook occurred, and the median lobe is carinated ventrally as in Candezea . The shape of the spermatheca of Neolepta resembles that of Candezea , with long curved cornu, but in Neolepta two pairs of bursa sclerites occurs, while in Candezea only one pair exist. There are also two pairs of bursa sclerites in Monolepta , but they are lacking in Arcastes .

Differences to the herein newly described genera Orthoneolepta , new genus and Paraneolepta , new genus are described in detail in the diagnoses of those new genera. An easily recognisable external character to Orthoneolepta , new genus are the significantly widened fourth to sixth antennomere are, while species of Paraneolepta , new genus are much larger and characterised by the long and slender antennomeres. Most important are the very different genital patterns in both sexes that characterise these three groups.

Figures

Fig. 1. Neolepta sumatrensis (Jacoby, 1884): a, head; b, prothorax; c, meso- and metathorax, ventral view; d, hindwing, right, dorsal view; e, prothoracic leg; f, mesothoracic leg; g, metathoracic leg; h, female abdomen; i, male abdomen. Scale bar = 1 mm.

Figs. 2–6. Neolepta sumatrensis (Jacoby, 1884). 2, dorsal colour pattern. 3, antennae: a, male; b, female. 4, Median lobe: a, dorsal; b, lateral; c, ventral. 5, three different spermathecae. 6, two pairs of bursa sclerites. Scale bar = 1 mm.

Figs. 10–14. Neolepta quadriplagiata Jacoby, 1886. 10, dorsal colour pattern. 11, antennae: a, male; b, female; 12, median lobe: a, dorsal; b, lateral; c, ventral. 13, three different spermathecae. 14, two pairs of bursa sclerites.

Fig. 7. Distribution of N. sumatrensis (Jacoby, 1884) and N. quadriplagiata Jacoby, 1886.