Caccomolpus Sharp, 1886

Leschen, Richard A. B., Reid, Chris A. M. & Nadein, Konstantin S., 2020, Generic Review of New Zealand Chrysomelinae (Coleoptera: Chrysomelidae), Zootaxa 4740 (1), pp. 1-66 : 11-14

Caccomolpus Sharp, 1886

( Figs 1C, D, F , 13B)

Caccomolpus Sharp, 1886:447 . Type species: Caccomolpus globosus Sharp, 1886 , here designated.

Diagnosis. Body length 2.5–5.8 mm; rounded to elliptical, strongly convex; unicoloured and rarely metallic green. Antennae very weakly clavate, filiform to subfiliform. Procoxal cavities externally open. Hindwings absent. Anterior edge of metaventrite straight; metaventral lines distal, and not parallel and often extending to middle of ventrite. First abdominal ventrite with well-developed convex subcoxal lines sometimes extending to middle of ventrite.

Description. Length 2.4–5.8 mm. Body rounded to elliptical, moderately to strongly convex; dorsal colouration unicoloured dark to black, rarely with green metallic sheen.

Head not forming a short muzzle with genae extending a short distance beyond level of antennal and maxillary insertions, visible from above with mouthparts directed ventrally or anteroventrally, wide vertex or frons, nearly flat to feebly convex; postantennal calli weakly developed or absent, pale areas present or absent. Eyes relatively well-developed and weakly or not protuberant, coarsely facetted and consisting of about 20–30 ommatidia; inner margin of eye without a small seta. Antennae long, filiform, subfiliform or weakly clavate, antennomeres 5-, 6- or 7–11 forming a weak club, reaching beyond the hind margin of the pronotum; eye not contacting insertion in most speciers, with distance between insertion and margin of eye at most the diameter of insertion, distance between insertions about 4–6 times length of the scape. Clypeus transverse to somewhate trapezoidal, anterior margin straight; frontoclypeal suture present or very weakly impressed; postclypeal lines present or absent. Labrum somewhat rectangular to quadrate, anterior margin weakly to moderately emarginated and sides rounded, surface with 3–4 elongate setae per side, anterior margin at middle lacking distinct setal fringe, tormae long and thin, about 2–3 times longer than labral plate. Mandible with terebral edge simple. Maxillary palpus relatively long, palpomere 1 longer than wide, palpomere 2 transverse and shorter than wide, palpomere 3 about 2 times longer than wide, greater in length than palpomere 2, conical to weakly acute with truncated apex. Labium with relatively narrow ligula, less or equal to the width to the lengths of palpomeres 1 and 2 combined, apex not divided at apex, palpal insertions separated by less than the width of the basal palpomere, palpi relatively short, palpomere 1 more or less quadrate, palpomeres 2 and 3 each two times longer than wide with palpomere 3 conical. Mentum rectangular and transverse 2 to 5 times wider than long, width of mentum about equal to the length of labial palpomere 3. Intermaxillary process basically absent and not extending anteriorly beyond maxillary insertions, delimited behind by a ridge or a bead.

Pronotum transverse and convex, with a bead along anterior and lateral margins; posterior edge as wide as base of elytra; anterior margin weakly moderately emarginated, anterior angles weakly projecting and rounded to subacute; sides distinctly converging anteriad and straight or curved, posterior margin weakly convex or sinuate; posterior angles acute; disc moderately to strongly convex without sublateral groove, trichobothria absent, coarse and dense punctures at middle of posterior margin absent; lateral carinae complete. Prosternum vaulted at middle between prosternal lines, or not, without transverse notches in front of coxal cavities; prosternal lines present and usually parallel (rarely convergent anteriorly, e.g., C. flectipes Broun ), and extending forward almost reaching anterior edge of sternite; prosternal process broad, short and extending a short distance behind procoxae, expanded just slightly laterally behind coxae and not contacting the hypomeral process (hypomeral process acute to rounded); posterior margin straight, weakly rounded or concave, procoxal cavities externally open. Notopleural suture distinct. Scutellary shield visible and relatively small, triangular with rounded, subacute or acute apex. Elytra strongly to moderately convex, humeral calli and midbasal striae mainly absent (rarely present and poorly developed); surface smooth, punctures weakly to deeply impressed and striate (rarely confused), epipleura wide and well developed, visible in lateral view, apex without ctenidium. Hind wings absent. Mesoventrite mostly hidden in ventral view, posterior portion between mesocoxae visible as a narrow strip; mesal part of mesoventrite with vertical surface confluent with prepectus. Meso- and metacoxae widely separated. Metaventrite subequal to length of abdominal ventrite 1 at midline, mesocoxal process very short and broad with a straight or rounded anterior margin, metaventral lines distal and not parallel to coxal cavity, especially laterad, discrimen present and transverse metaventral (metakatepisternal) suture present but does or does not cross the midline. Metendosternite lacking stalk and laminae, widely spaced lateral arms with subapical anterior tendons. Legs with tibiae variable, flattened in cross section or not; meso- and metatibiae clubbed or gradually expanded distally with outer edge evenly curved, apically setose; tarsomeres 5-5-5, tarsomere 1 longer than wide and 2–3 times longer than T2 (up to 4 times more in males), T2 transverse and wider than long and as long as T3, T3 about as wide as long or transverse and deeply to weakly incised (bilobed), tarsomere 4 minute, T5 about 2–3 times long as T3, claws simple.

Abdominal ventrite 1 long, but shorter than ventrites 2–5 combined, with a broad metacoxal process that is wider than long and with a straightt apical margin, ventrites 2–4 equal in length and much shorter than ventrite 1, ventrite 5 subequal or longer than ventrites 3 and 4 combined with rounded posterior margin; first abdominal ventrite with subcoxal lines distal to coxal cavity and extending to middle of ventrite. Aedeagus curved to weakly curved in lateral view and rounded in cross section; apex in dorsal view subacute or rounded; flagellum present or absent. Ovipositor with coxite elongate, at least 4 times longer than wide, stylus absent. Spermatheca curved, Ushaped, collum absent and present with spermathecal duct inserted onto base, spermathecal gland absent.

Comments. This endemic genus comprises 14 described species (including two species transferred here from Aphilon and excluding four transferred to a new genus). The genus was described by Sharp (1886) who included two very different species in his original paper. We designate C. globosus Sharp as the type species, the other, Caccomolpus plagiatus Sharp , is placed in a new genus below ( Maurodus ), together with Caccomolpus cinctiger Broun , Caccomolpus maculatus Broun, 1893 , and Caccomolpus ornatus Broun, 1910 . Caccomolpus also includes the species Aphilon laticollis and A. pretiosum , and apart from these two species transferred from Aphilon , the remaining species were described from the South Island, mostly from the highlands. Smaller Caccomolpus species that are similar to members of Aphilon can be distinguished from them by their small size, the head scarcely visible in dorsal view, and subcoxal lines on abdominal ventrite 1 which are not parallel to the metacoxal cavity that have a wide space and convex shape and often extend to the middle of the ventrite ( Fig. 1F ). The Aphilon -form of the subcoxal lines also occurs in Caccomolpus cinctiger Broun , Caccomolpus maculatus Broun, 1893 , Caccomolpus ornatus Broun, 1910 , and Caccomolpus plagiatus Sharp , and several additional species mainly from the South Island which can be characterised by having subcoxal lines on first abdominal ventrite parallel and approximate to metacoxal cavity: these we place in a new genus, Maurodus , below.

All species live at ground level and can be sifted from leaf litter or moss, though some specimens have been collected at night from foliage above ground.

We are unable to provide a key to the species as the validity of the described species is unknown and unchecked.

Included species. Caccomolpus amplus Broun, 1921 , C. flectipes Broun, 1914 , C. fuscicornis Broun, 1917 , C. globosus Sharp, 1886 , C. hallianus Broun, 1917 , C. laticollis (Broun, 1893) , comb. nov. (from Aphilon ), C. montanus Broun, 1921 , C. nigristernis Broun, 1917 , C. pretiosus ( Broun, 1880) , comb. nov. (from Aphilon ), C. pullatus Broun, 1893 , C. subcupreus Broun, 1921 , C. substriatus Broun, 1917 , C. tibialis Broun, 1917 , C. viridescens Broun, 1917 .

Distribution. North Island, South Island, Stewart Island.

Figures

FIGURES 1A–F. Habitus and structures of Aphilon and Caccomolpus; A, Aphilon sp., dorsal view, length 2.2 mm; B, Aphilon sp., lateral view; C, Caccomolpus sp., dorsal view, length 2.7 mm; C, Caccomolpus sp., dorsal view; D, Caccomolpus sp., lateral view; E., Aphilon sp., front of head; F, Caccomolpus sp., abdominal ventrites.