Parageron longilingua, Gibbs, 2023

Gibbs, David, 2023, A world review of the bee fly tribe Usiini (Diptera, Bombyliidae) - Part 3: Parageron Paramonov s. lat., European Journal of Taxonomy 863 (1), pp. 1-162 : 44-47

Parageron longilingua sp. nov.

urn:lsid:zoobank.org:act:AC56250F-6D06-4590-B32D-9FFBCF92D90B

Figs 2 , 4 , 28 , 37

Etymology

Noun in apposition, ‘long tongue’, ‘ longus ’ = ‘long’ and ‘ lingua ’ = ‘tongue’ from Latin.

Type material

Holotype

CYPRUS • ♂; “ Nicosea 16 August 1933 ♂ leg. T. Shiakides [ NHMUK014064125 ]”; NHMUK.

Paratypes

CYPRUS • 1 ♂; “ Nicosea 16 August 1933 ♂ leg. T. Shiakides [ NHMUK014064126 ]; NHMUK • 1 ♀; “Cherkes 18 June 1934 leg. G. Mavromoustakis [ NHMUK014064127 ]”; NHMUK • 1 ♀; “ Limassol ( ZW), Akrotiri 25 June 2000 leg. J. Janssens ”; PCJD .

ISRAEL • 1 ♂, 2 ♀♀; “ Berekhat Ya’ar , 7 July 2005, L. Friedman ”; TAU • 4 ♀♀; “ Herzliyya , hill, 32°11′N 34°49′E, 18 August 2007, A. Freidberg ”; TAU • 1 ♂; 22 August 2007 ”; TAU • 1 ♀; “ Sedi Boqer , 20 June 1970, leg Kulger”; TAU • 1 ♀; “ Ein Akev , 8 August 1977, A. Freidberg ”; TAU • 1 ♀; “ Tel-Aviv, 3 October 1977, A. Freidberg ”; TAU .

Other material examined

Intermediate Par. lutescens / Par. longilingua sp. nov. material.

ISRAEL • 1 ♂; “Jerico, Palestine, 23 August 1973, leg. Bytinski-Salz ”; TAU • 1 ♂; “ Arad , Israel, 30 June 1970, leg. Kugler [♂]”; TAU .

Description

MEASUREMENTS. Body length: 2.5–4.5 mm. Wing length: 2.8–4.8 mm.

Male

A variable species, possibly a species complex or even an extreme variety of Par. lutescens (see discussion below). This description is based on Israeli specimens, with reference to Cypriot specimens where different.

HEAD. Gena relatively broad, at level of proboscis wider than depth of postpedicel, remaining almost parallel sided onto frons, entirely yellow in ground colour with thin coating of silky white dust, a slightly shinier border to the oral opening below. Frons in dorsal view approximately equilateral, almost straight laterally, with short but distinct erect pale brown hairs, longer than pedicel (a little shorter in Cypriot specimens). Eyes confluent for longer than long axis of ocellar tubercle, about 13 facets and a little longer than the frons (about equal in Cypriot specimens). Ocellar tubercle dark brown to blackish, brown dusted (grey in Cypriot specimens), all ocelli in direct contact with the eyes; a narrow, acute dark triangle in front of front ocelli. Longish, pale yellow proclinate hairs on ocellar tubercle, a little longer than the distance across the hind ocelli. Eye facets in the upper two thirds (three fifths in Cypriot specimens) enlarged, at least twice the size of those in lower part, rather sharply demarcated. Occiput, darker yellow than frons, variably dark in ground colour around neck, thinly yellowish dusted and covered with pale yellow hairs longer than length of scape and pedicel combined (white dusted and haired in Cypriot specimens). Antennae with scape and pedicel yellow, a little darker than frons, postpedicel variably brownish to brown-yellow little darker than pedicel, significantly longer than scape and pedicel together. The tip of this segment variable, simply pointed (Cypriot specimens) or with a double point, the lower one long or short; erect pale hairs along dorsum of segments, especially scape and pedicel. Palps small and slender, not swollen apically, pale yellow with short yellowish hairs. Proboscis conspicuously long, a little variable but often longer than the remainder of the body, swollen base yellow, the rest blackish. Labrum swollen basally but less so than in most Par. lutescens , labium brownish shading into blackish apical half and labella, the basoventral membrane dark yellow.

THORAX. Yellow in ground colour, mesonotum with three variable black vittae, sometimes clearly separated by yellow dorsocentral lines (Cypriot specimens) and the mid-vittae ending before reaching the scutellum, often the black vittae coalescing such that the mesonotum is entirely dark on the disc (Israeli specimens) obscured by rather dense golden (whitish in Cypriot specimens) dust. On each side of the thorax are dust-free, velvety, roundish black spots on the thoracic suture. Just behind the suture and above the wing base is an often obscure (missing in one Cypriot specimen), roundish dark spot, occasionally coalescing with lateral dark vittae. In more densely dusted individuals, viewed from behind, three narrow, darker vittae can be apparent superimposed on the median black ground-colour. Hairs of mesonotum very pale yellow, narrowly absent on paramedian vittae, denser on anterior half, rather sparse on disc behind thoracic suture, mid-length, longest laterally, longest hairs almost as long as postpedicel, anteriorly reclinate, in hind third erect to slightly proclinate. Scutellum dull brown (yellow in Cypriot specimens), pale yellow hairs as on mesonotum. Pleura dark yellow in ground colour, katepisternum black ventrally, meron black postero-ventrally, anepisternum with a darker, blackish lower half, all densely yellow dusted (Cypriot specimens paler and white dusted). Pronotum and anepisternum with yellow hairs like those on notopleuron.

WING. Membrane with a very faint yellow tinge, the veins brown, yellow basally (entirely yellow in Cypriot specimens). Crossvein r-m at basal third of the discal cell, distinctly beyond m-cu. Anal lobe well developed with conspicuously convex margin, noticeably broader than anal cell.

HALTERE. Knob whitish with a distinct brown spot dorsally, stem yellowish, slightly darker at base (knob all white in Cypriot specimens).

LEGS. Predominantly yellow except for apical tarsal segments which are variably blackish. In darkest specimens femora infuscated laterally and hind tibia apically brownish. Claws yellow basally with black apical half. Legs covered with short pale yellow hairs, longest on the coxae and femora, very short and adpressed on tibia and tarsi.

ABDOMEN. Tergites brownish-yellow on disc, paler laterally and on tergite one, each tergite with a pale ivory apical margin occupying about a quarter to a third the length of the visible tergite, narrower on tergite one (Cypriot specimens much paler, like Par. lutescens ). All tergites yellow dusted, less densely than on mesonotum (white dusted in Cypriot specimens) with mid-length pale hairs those on disc about as long as the respective tergite, laterally hairs hardly longer, hairs tending to be distinctly curved towards the tip of the abdomen apically. Sternites similar but mostly creamy-yellow, hairing as tergites. GENITALIA. Mostly dark yellow, gonocoxite basally blackish, small but quite conspicuous, the epandrium rectangular, dusting and hairing similar to tergites but conspicuously shorter. The two forms treated above differ in their epiphallus, Israeli specimens hardly differing from Par. lutescens, Cypriot specimens darker, more sclerotised and slightly different in shape.

Female

As male but generally paler with more limited areas of blackish ground colour and generally shorter hairs. Gena a little broader than in male, broadening towards frons. Frons about one third head width, conspicuously narrowing towards vertex, dark yellow-brown with golden dusting and very short yellowbrown hairs. Ocellar triangle equilateral to slightly acute, hind ocelli separated from eye margin by 1.5 to two times diameter of that ocellus. Hairs on ocellar tubercle no longer than those on adjacent part of frons.

Remarks

It has in common with Par. lutescens , a large amount of variability, even within the limited series available from Cyprus and Israel. Initially, when only Cypriot Par. longilingua sp. nov. and West African Par. lutescens were available for study, and the holotype of Par. orientalis had not been seen, these two taxa seemed to be abundantly distinct, with external morphology correlating with genitalia structure. Photos of the holotype of Par. orientalis combined with specimens of Par. orientalis from northern Iran showed that this taxon could not be Par. orientalis . However, material from Israel considerably confused the issue. These specimens share the very long, black proboscis, only slightly swollen basally, with Cypriot specimens but are darker and dusted golden brown rather than white. As such they look more distinct from Par. lutescens than do Cypriot specimens. However, on dissection, while the epandrium proved to be similar to that of Cypriot specimens (a subtle character) the epiphallus is clearly of the Par. lutescens form.

The situation is further complicated by two male specimens from Israel which have the pale yellow cuticle and genitalia of Par. lutescens . However, their proboscis is about half the length of other Par. longilingua sp. nov. specimens but twice that of typical Par. lutescens . Also, these specimens have the base of the proboscis only slightly swollen, just as in Par. longilingua . While the possibility exists that these two represent hybrids between Par. lutescens and Par. longilingua , I suspect that they are merely examples of extreme variation in Par. longilingua .

With the material available to me during this study, it does not seem possible to satisfactorily resolve the intricacies of the Par. lutescens - longilingua complex. More detailed investigation might conclude that it is a single very labile taxon or six or more distinct species, only more material and probably molecular techniques will resolve it.

Distribution

Cyprus and Israel.

Figures

Fig. 2. Parageron longilingua sp. nov., ♂.

Fig. 4. Parageron longilingua sp. nov., ♂.

Fig. 28. Parageron longilingua sp. nov., ♀.

Fig. 37. Parageron longilingua sp. nov. a. Epiphallic complex ventral. b. Epiphallic complex lateral. c. Gonocoxite ventral. d. Gonocoxite lateral. e. Epandrium dorsal. f. Female genitalia ventral.