Кавказский энтомологический бюллетень 15(1): 211–214 © Caucasian Entomological Bulletin 2019

A new species of robber fly of the genus Leptogaster Meigen, 1803 (Diptera: Asilidae) from Dagestan, Russia

Новый вид ктыря рода Leptogaster Meigen, 1803 (Diptera: Asilidae) из Дагестана, Россия

© D.M. Astakhov

© Д.М. Астахов

Volgograd State University, Universitetskiy av., 100, Volgograd 400062 Russia. E-mail: dmitriy_astachov@mail.ru, astakhov@volsu.ru Волгоградский государственный университет, Университетский пр., 100, Волгоград 400062 Россия

Key words: Diptera, Asilidae, Leptogaster, new species, Dagestan, Russia.

Ключевые слова: Diptera, Asilidae, Leptogaster, новый вид, Дагестан, Россия.

Abstract. A new species Leptogaster rutulica sp. n. from southwestern Dagestan is described with comprehensive photographs of the external morphology and details of the male genitalia. Differences from other species of the genus Leptogaster Meigen, 1803, and especially from the closely related species L. subtilis Loew, 1847 are shown. The species is characterized by the presence of very characteristic features, which are not observed in other members of Leptogaster species occurring in the Caucasus. The new species differs from

L. armeniaca Paramonov, 1930, L. calceata Engel, 1925,

L. cylindrica (De Geer, 1776) and L. pubicornis Loew, 1847 in the shape of the epandrium with a distinct spine medio- posteriorly, by the presence of numerous black hairs and strong bristles at the tip of the epandrium, and the lateral processes of gonostyli sharply curved and bent down. The new species has two extensive apubescent areas on the mesoscutum, reaching the middle of the mesonotum and also clearly distinguished from Leptogaster subtilis by the presence of the distinct spine medio-posteriorly on the epandrium.

Резюме. Описан новый вид Leptogaster rutulica sp. n. из Юго-Западного Дагестана с

подробными фотографиями деталей внешнего строения и описанием гениталий самца. Показаны отличия от других видов рода Leptogaster Meigen, 1803 и в особенности от близкого вида L. subtilis Loew, 1847. Новый вид имеет по бокам от срединной бурой полосы два длинных лишенных пыльцы участка, доходящих до середины среднеспинки и также хорошо отличается от Leptogaster subtilis небольшим отчетливым заостренным выступом по медиальному краю половин эпандрия.

According to recent data, the genus Leptogaster Meigen, 1803 accounts for 254 species in the world fauna and 54 species in the Palaearctic [Hasbenli et al., 2006]. Representatives of the Leptogastrinae subfamily are not waiting for the prey sitting still, but rather catch their prey while flying in dense vegetation. Various arthropods seated on plants (small dipterans, leafhoppers, grasshoppers

Short Communication / Краткое сообщение DOI: 10.23885/181433262019151-211214

larvae, bugs, aphids, and sometimes spiders [Lehr, 1961]) can serve as prey.

When studying collections from Dagestan provided by

K.A. Grebennikov, we found a male of a species previously unknown to science. The identification of the specimen using the available identification keys for the Caucasus and the nearest territories [Richter, 1968, 1969; Lehr, 1961; Astakhov, 2015], as well as a comparison with reliably determined and typical specimens of various species of the genus Leptogaster in the collection of the Zoological Institute of the Russian Academy of Sciences (St Petersburg,

Figs 1−2. Leptogaster rutulica sp. n., male, holotype.

1 – general view; 2 – legs, lateral view. Scale bars 1 mm. Рис. 1−2. Leptogaster rutulica sp. n., самец, голотип.

1 – общий вид; 2 – ноги, вид сбоку. Масштабные линейки 1 мм.

212 D.M. Astakhov

Russia) did not allow determining the species of this specimen. Richter [1968] lists for 4 species of Leptogaster (L. armeniaca Paramonov, 1930, L. calceata Engel, 1925,

L. cylindrica (De Geer, 1776) and L. pubicornis Loew, 1847) for the fauna of the Caucasus. In the neighbouring Lower Volga region 6 species of Leptogaster (L. cylindrica (De Geer, 1776), L. fumipennis Loew, 1871, L. guttiventris Zetterstedt, 1842, L. nartshukae Lehr, 1961, L. pubicornis Loew, 1847, L. stackelbergi Lehr, 1961 [Astakhov, 2015]) have been discovered. The new species is not similar to any of these species and has completely different male genitalia structures. The closest in structure of the male genitalia is L. subtilis Loew, 1847, which is known from Western and Eastern Europe (Spain, France, Belgium, Germany, Switzerland, Italy, Austria, Czech Republic, Slovakia) [Engel, 1930; Lehr, 1988; Weinberg, Bächli, 2005, 2008]. Lehr [1961, 1988] records L. subtilis in Tajikistan, which is considered erroneous and the specimens apparently belong

to the species L. lehri Hradsky et Hüttinger, 1983, described from Afghanistan [Hradsky, Hüttinger, 1983; Weinberg, Bächli, 2005]. We took detailed photos of the male

L. rutulica sp. n. appearance and genitalia structures. The holotype of the new species is deposited in the collection of the Zoological Institute of the Russian Academy of Sciences.

Leptogaster rutulica sp. n.

(Figs 111)

Material. Holotype, ♂: Russia, Dagestan, Rutul District, W of Kufa vill., 41.566 N / 47.361 E, 1400 m, 1.07.2018 (leg. K.A. Grebennikov).

Description. Face covered in silvery-white pubescence, mystax composed of four macrosetae, arranged in one row; occiput covered in brownish-gray pollen; scape, pedicel and proximal half of postpedicel reddish-yellow, distal half of postpedicel and style brown; proboscis reddish-yellow (Figs 1–4). Mesoscutum covered with grayish-brown pollen with two black, shiny round spots

Figs 3−8. Leptogaster rutulica sp. n., male, holotype.

3–4 – head and thorax: 3 – lateral view, 4 – dorsal view; 5–8 – genitalia: 5, 8 – lateral view, 6 – ventral view, 7 – dorsal view. Scale bars 0.5 mm. Рис. 3−8. Leptogaster rutulica sp. n., самец, голотип.

3–4 – голова и грудь: 3 – вид сбоку, 4 – вид сверху; 5–8 – гениталии: 5, 8 – вид сбоку, 6 – вид снизу, 7 – вид сверху. Масштабные линейки 0.5 мм.

A new species of robber fly of the genus Leptogaster Meigen, 1803 (Diptera: Asilidae) from Dagestan, Russia 213

laterally and two black shiny stripes in middle, not reaching distal margin (Figs 1–4); pleurae covered with brownish-gray pollen (Figs 1, 2). Wings uniformly slightly brownish darkened. Coxae reddish-yellow; legs are in short light with a slight admixture of black hairs and setae; fore and mid femora reddish-yellow with black tips; hind femora with distinct black ring in near distal tip; fore and mid tibiae reddish-yellow; hind tibiae with black tip; proximal 2 tarsomeres of hind tarsus reddish-yellow, tip brown, other tarsomeres completely brown (Figs 1, 2); abdomen covered with grayish-brown pollen and thin silvery-white hairs (Fig. 1).

Male genitalia black-brown, with long thin light and black hairs (Figs 5–11); epandrial halves with small pointed spine medio-posteriorly and deep notch distally; epandrial halves distally enlarged and covered with numerous black hairs and strong setae; gonocoxite-hypandrial complex is covered with white hairs; gonostylus elongated and slightly curved in medially; lateral processes of gonostyli elongated, flattened and sharply bent downwards; aedeagus smoothly narrowed toward apex; ejaculatory apodeme small and elongated.

Body length 10 mm.

Comparative diagnosis. The species is characterized by the presence of very characteristic features, which are not observed in other members of Leptogaster species occurring in the Caucasus. The new species differs from

L. armeniaca, L. calceata, L. cylindrica and L. pubicornis in the shape of the epandrium with a distinct spine medio- posteriorly (Figs 7–11), by the presence of numerous black hairs and strong bristles at the tip of the epandrium, and the lateral processes of gonostyli sharply curved and bent down (Figs 5, 8, 9). Among the external characters, noteworthy are the characteristic pattern on the mesoscutum and the colour of the hind tarsus (Figs 1–4). It also differs from the morphologically similar species L. subtilis by the presence of the distinct spine medio-posteriorly on the epandrium (Figs 7–11). Leptogaster rutulica sp. n. has two extensive apubescent areas on the mesoscutum, reaching the middle of the mesonotum (Fig. 4) whereas

L. subtilis has significantly less extensive pubescent areas [Weinberg, Bächli, 2008]. Detailed drawings of the external morphology and details of the male genitalia of L. subtilis are well represented in the work of Weinberg and Bächli [2008: 233–239, figs 1–7]. The L. subtilis illustrations from this article and our photographs of L. rutulica sp. n. allow to reliably identify these two close species.

Etymology. The name is given by the place of collection, Rutul District.

Distribution. Southwestern Dagestan, Russia.

Acknowledgements

The author expresses his sincere acknowledgement to K.A. Grebennikov (All-Russian Centre for Plant Quarantine, Moscow, Russia), who provided his collections for the study, as well as to the staff of the Department of Coleoptera of the Laboratory of Insect Taxonomy of the Zoological Institute of the Russian Academy of Sciences (St Petersburg, Russia) for the opportunity to prepare photographs on the stereomicroscope Leica MZ 9.5 with the camera DFC 290.

The reported research was funded by Russian Foundation for Basic Research and the government of Volgograd Region (Russia), grant № 18-44-343001.

Figs 9−11. Leptogaster rutulica sp. n., male genitalia, holotype.

9 – lateral view; 10 – dorsal view; 11 – ventral view. Scale bars 0.5 mm. Рис. 9−11. Leptogaster rutulica sp. n., гениталии самца, голотип.

9 – вид сбоку; 10 – вид сверху; 11 – вид снизу. Масштабные линейки 0.5 мм.

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Received / Поступила: 16.12.2018 Accepted / Принята: 13.02.2019