Cychrus semigranosus Palliardi, 1825

Busato, Enrico, 2012, semigranosus Palliardi, 1825, with a key to the larvae of the European Cychrus species (Coleoptera: Carabidae), Zootaxa 3361, pp. 1-17 : 7-10

Cychrus semigranosus Palliardi, 1825

Larva very similar to that of the species described above; colour brown-reddish. Length from mandible tip to end of urogonphi (excluding macrochetae): first instar 9.4 – 10.2 mm.

Head subquadrate; chaetotaxy of the cephalic region as shown in Fig. 17. The frontoclypeolabrum is nearly as wide as long: l/w ratio: 1.06 – 1.08. The frontoclypeolabrum has very prominent lateral lobes outside and forwards that are markedly distinct from the median lobe; in the lateral view it is flattened in the proximal area, and markedly thickened in the distal area. Approximately along the middle of its length it forms a convexity that gently slopes down distally and laterally, finally forming two distinct slanted folds in the insertion areas of the lateral lobes, at the sides of the median lobe. The latter, in the lateral view, is prominent and almost of the same thickness as the median convexity.

Eye area not very prominent and has six stemmata and three setae (PA 7, PA 9, PA 13).

The frontoclypeolabrum margins and the chaetotaxy are similar to those of C. schmidti . In the first instar larvae, the ruptor ovi is formed by a single pointed spinula on the two sides that are anteriorly oriented ( Fig. 17).

Antennae ( Figs. 17, 18) very pubescent, almost twice as long as the mandibles (a/M ratio: 1.95–2.02). The shape, ratios and chaetotaxy are all as for C. schmidti .

Mandibles ( Fig. 19) falciform, narrow and elongated, with the retinacle sharpened and curved, with small pointed teeth in the internal margin, at the base of which there is a tuft of setae (penicillium). The internal margin of the mandibles has several small pointed teeth, arranged in the distal third of the mandible. Only one seta (MN 1) is present on the external margin.

Maxillae ( Figs. 20, 21) longer than the mandibles, m/M ratio = 1.34–1.46. The stipe is nearly twice as long as wide, is not apically dilated, and has several setae on the internal edge of the dorsal side (gMX). The articles of the maxillary palps have the same shape and ratios as found in C. schmidti , while the chaetotaxy is different, in particular in the first two articles of the maxillary palps, due to a group of supernumerary setae.

Labium ( Figs. 22, 23) with two pairs of ventral setae (LA 1, LA 2), with several dorsal setae (LA 3, LA 4, LA 5, gLA 3). The ligula has a pair of long setae (LA 6). The first article of the labial palps is subcylindrical, slightly or not enlarged distally, shorter than half the second, and dorsally provided with 5 – 6 setae on the distal third (gLA b); the second article is subcylindrical, ovoid, flattened and truncated apically.

Thorax ( Fig. 24) completely glabrous. The pronotum, mesonotum and metanotum are subtrapezoidal. The width of the segments increases progressively from the pronotum to metanotum. The pronotum is slightly longer than the other two thoracic segments.

Urotergites ( Fig. 25) completely glabrous, with a shape and ratio similar to C. schmidti . The abdominal sclerites (number and location) are similar to the ones described for the previous species.

Urite IX ( Fig. 26) with prominentand glabrous latero-posterior lobes with rounded tips.

Urogomphi short, conical, straight and almost parallel, lacking a lateral spine and bearing just two to three short setae each apically (UR 7, UR 8, UR 9). Seta UR 5 is absent.

Legs ( Fig. 27) long, decisively more hirsute than in C. schmidti , with the addition of several indefinite setae compared with the model proposed by Makarov (1993) for the genus Carabus . Moreover, there are many very thin setae along the dorsal profile of each segment, forming a tender down.

One left metathoracic leg of a first instar larva was taken as an example and showed the following ratios: (C: coxa, T: trochanter, F: femur, t: tibia, ta: tarsus): T/C = 0.55; F/C = 0.70; t/C = 0.41; ta/C = 0.68.