Leptochilus (Lionotulus) quintus GUSENLEITNER , 1991

Polašek, Ozren, 2022, The description of Leptochilus quintus GUSENLEITNER, 1991, female, with further notes on its distribution and life cycle (Hymenoptera, Vespidae), Linzer biologische Beiträge 54 (1), pp. 251-256 : 252-254

Leptochilus (Lionotulus) quintus GUSENLEITNER, 1991

M a t e r i a l e x a m i n e d: CROATIA: Mosor mountain , Gornje Sitno, mountain path [43.516418, 16.617555; 623 m above sea level], 29.5.2022, leg. O. Polašek, 1♁, 2♀♀ ; Mosor mountain , Gornje Sitno, mountain path to the observatory [43.504880, 16.609562; 623 m asl], 6.6.2022, leg. O. Polašek, 1 ♁; Mosor mountain , Zagrade, the path near dried stream [43.525685, 16.597307; 616 m asl], 5.6.2022, leg. O. Polašek, 1♀ ; Kozjak mountain , Blaca, dirt road [43.525685, 16.597307; 418 m asl], 2.6.2022, leg. O. Polašek, 3♁♁, 3♀♀ ; Dinara mountain , mountain path [44.027356, 16.406618; 995m asl], 3.6.2022, leg. O. Polašek, 1♀ .

D e s c r i p t i o n:

Diagnosis: This species is characterized by the following combination of features: basally black body with whitish or yellow markings on tegula, T1 and T2, strong punctation of T2 and S2, T2 lamina with shorter interdigitations, evenly curved occipital carina and dark-brown tarsi in combination with brownish tibia that have yellow outer surface. Wing length: 4.1-4.3 mm (head+thorax+T1+T2 ~ 5.6-5.9 mm).

Colour: The ground colour is black with whitish markings (all markings become yellowish after drying; Figure 1a ). Head frontally completely black ( Figure 1b ). Three examined specimens have smaller yellow bilateral spot on the pronotum ( Figure 1a, 1c ), while two specimens have an entirely black pronotum. Whitish markings include the lateral part of the tegula, a posterior band on T1 and T2, with an occasional spot or a short triangular remnant of a posterior band on S2 ( Figure 1a ; notably, all of these markings can also be yellowish in some specimens). Femora basally black, distally brown, and terminally yellow ( Figure 1a ). Tibia and tarsi brownish-red, but the external tibia surface is yellow ( Figure 1a ; in contrast to L. crassipunctatus (MAIDL, 1922) , with orange-brown tibia and tarsi or L. hermon GUSENLEITNER, 1971 females, with blackish or black markings on all three tibia pairs). Wings dark-grey, nervature and stigma dark brown to black ( Figure 1a ), as opposed to brownish nervature and overall brownish wing colour in L. crassipunctatus (MAIDL, 1922) . The antenna entirely black ( Figure 1d ), but a few terminal flagellomeres ventrally reddish in two specimens (in contrast to L. hermon GUSENLEITNER, 1971 females, which have most of the distal flagellomeres reddish ventrally).

Head: Head about 1.1x wider than long ( Figure 1b ). The interantennal distance about 2.4x of the socket-eye distance ( Figure 1b ). Clypeus 1.3x wider than long, with rounded basal margin and moderately projecting apex ( Figure 1b ). The apical excavation of the clypeus comparatively deeper and circular ( Figure 1b ). The central surface of the clypeus with intermediate-sized and coarse punctation, smaller and less coarse than in L. crassipunctatus (MAIDL, 1922) . The lateral and basal margin of the clypeus covered by silvery pubescence, which is much sparser in the centre and the apex. The inner orbit and inter-antennal area covered by short and dense silvery pubescence, while the frons is covered by somewhat longer yellowish setae; those on the frons are about 0.7x of the anterior ocellus diameter ( Figure 1a ). The antennal scape is coarsely punctated, and covered by silvery pubescence, which is at most 0.5x of its basal width ( Figure 1b ). The frons and vertex, as well as gena and tempora densely and coarsely punctated. The occipital carina is evenly curved along the entire length, as opposed to an angular contour in L. tarsatus (DE SAUSSURE, 1855) , L. hermon GUSENLEITNER, 1971 and L. alpestris (DE SAUSSURE, 1855) .

Mesosoma The entire mesosoma is coarsely and densely punctated; punctation on the pronotum is larger than the inter-punctum surface, with occasional weak reticulation. The pronotal carina moderately developed, interrupted medially in some specimens, but laterally creates an almost the right angle in all examined specimens. Mesonotum about 1.1-1.2x wider than long, equally punctated, with somewhat denser punctation close to the scutellum. The mesonotal pubescence is slightly shorter (0.7-0.8x) than that on the frons. Mesopleura covered by a similar punctation, which becomes somewhat less dense towards the ventral part of the body. Scutellum covered by large and dense punctation, stronger and denser than in L. tarsatus (DE SAUSSURE, 1855) . Metapleura horizontally striated, with punctation in the lateral half. Metanotum with the irregular apical margin, with nearly the entire surface punctated. The propodeal excavation without the superior carina, in contrast to L. alpestris (DE SAUSSURE, 1855) , which has developed carina. In addition, the propodeal excavation is covered with weakly developed oblique striae and coarse and sparse punctation, which diminishes in size towards the valvula. The femora and tibia covered by the short silvery pubescence, the tarsal segments parallel-sided.

Metasoma: T1 comparatively wider, covered by the coarse punctation. T2 covered by large and coarse punctation, which becomes less coarse dorsally, but it remains visible even in the posterior whitish band of T2. The T2 lamella about as long as the T2 posterior whitish band width, yellow and translucent, with punctation interdigitations that do not reach the half of the lamella length, as opposed to L. crassipunctatus (MAIDL, 1922) , which has longer interdigitations. S2 covered by a similar punctation to that on T2, which gradually becomes smaller, but equally spaced towards the S2 lamella. The S2 contour is similar to L. hermon GUSENLEITNER, 1971 and L. crassipunctatus (MAIDL, 1922) ( Figure 1a ); it is uneven, with a stronger convex beginning and a more flattened remaining surface, in contrast, the S2 contour is similarly convex during its entire length in L. tarsatus (DE SAUSSURE, 1855) and L. alpestris (DE SAUSSURE, 1855) . The remaining metasomal segments with a cuticular surface and weakly defined punctation.

Further notes on males: The single examined male specimen from Dinara mountain does not show any structural difference from other examined specimens. It has a wide black margin of clypeus, with only a central part remaining yellow. However, this specimen has a large bilateral yellow spot on the pronotum that occupies nearly the entire pronotum width. The absence of the translucent pronotal carina and short T2 lamella interdigitations suggests that this is not a misclassified L. membranaceus (MORAWITZ, 1867) , while the leg colour and clypeus shape disagree with four examined L. hermon GUSENLEITNER, 1971 specimens from Greece. The remaining six examined male specimens from Mosor and Kozjak mountains have either black pronotum or only a small yellow round spot. Wing length: 3.6-3.8 mm (head+thorax+T1+T2 ~ 4.5-5.6 mm).

D i s t r i b u t i o n: Croatia. The species was originally described from the Kvarner region ( GUSENLEITNER 1991), and later reported from Mosor mountain near Split ( POLAŠEK 2022).

Figures

Fig. 1. L. quintus GUSENLEITNER, 1991 female, a) habitus, lateral, b) head, c) habitus, dorsal, d) antenna, dorsal.