Desertepidosis Mamaev & Soyunov, 1989

Jaschhof, Mathias & Jaschhof, Catrin, 2019, New Dicerurini from Europe, mostly Sweden (Diptera: Cecidomyiidae, Porricondylinae), Zootaxa 4559 (2), pp. 245-264 : 246-247

Desertepidosis Mamaev & Soyunov, 1989

= Ubinomyia Mamaev, 1990 syn. nov.

Mamaev and Soyunov (1989) introduced this genus for two species from Turkmenistan, Stackelbergiella phryganophila Mamaev, 1966 and Desertepidosis pallida Mamaev & Soyunov, 1989 , assuming it was a faunal element of arid environments. Our finding in Sweden of a third species, D. borealis Jaschhof, 2013 , challenged this assumption. A recent taxonomic revision ( Jaschhof & Jaschhof 2013: 111ff.) revealed the dicerurine affinity of Desertepidosis and its resemblance to Ubinomyia and Arctepidosis , two genera established by Mamaev (1990). As regards Arctepidosis , a recent examination of the type species, A. jamalensis Mamaev, 1990 , made clear that this genus is justifiably regarded as distinct from Desertepidosis ( Jaschhof & Jaschhof 2017: 558ff.). In the present study we revisited the generic justification of Ubinomyia , with the result that this genus is no longer maintained as separate from Desertepidosis . Mamaev (1990) did not highlight characters distinguishing Ubinomyia from other porricondyline genera, but we found that a peculiarity in the male genitalia—the gonocoxal apodemes merged into a joint structure—was the only relevant distinction to Desertepidosis ( Jaschhof & Jaschhof 2013: 111) . As will be shown here, exactly the same structure is present in D. grytsjoenensis sp. nov., a species resembling D. borealis to such an extent that we did not differentiate between the two of them in our 2013 revision. With the inclusion of Ubinomyia cardinalis Mamaev, 1990 (the only species ever assigned to Ubinomyia ) and two new species described here, there are now six species classified with Desertepidosis . However, the basis for studying the taxonomy of this genus is everything but good: larvae remain unknown; the female of only one of the species ( D. cardinalis ) is described; and even males are rarely collected. As a result, three of the species have never been encountered outside their type localities; only two are represented in collections by more than three specimens; and only D. borealis has been found in more than one country. Why Desertepidosis are so rare is unclear, but interesting in this context is that three different species were found co-occurring in the same place in Sweden. All but one of 23 males studied here were obtained by Malaise trapping. Desertepidosis pallida , the only species with toothed gonostylus and markedly tapered tegmen (MJ, personal observation in 2012), might be misclassified in Desertepidosis and is retained in this genus only because a better, alternative placement is not available. New morphological information gathered here is used for updating the generic diagnosis (see Jaschhof & Jaschhof 2013: 112). Finally, a key to males is presented in order to facilitate the recognition of unnamed species, which are likely to be found in regions not yet surveyed for Desertepidosis .

Diagnosis. As pointed out earlier ( Jaschhof & Jaschhof 2013: 112), male morphology of Desertepidosis is decidedly regressive, with symptoms of degeneration found in the compound eyes (see the reduced eye bridge), antennae (several species with fewer than 14 flagellomeres), palpi (several species with only 3 short segments), and wings (narrow outline, vein M 4 vestigial or absent). The costal break, which is conspicuously wide, lies either before or behind the apex of the wing, and the claws are either untoothed or equipped with a large basal tooth, which both are variations seldom met in porricondylines supposed to be so closely related. Characteristic of Desertepidosis is the structure of the male genitalia, notably the gonostyli, which are large, subcylindrical, and toothless; the gonocoxae, whose large ventral emargination is U-shaped; the narrow, elongate tegmen, which lacks any fine structures; and the long, slender ejaculatory apodeme, whose base is strongly broadened in some of the species (as in many Neurepidosis , see below). Desertepidosis pallida , a species deviating from this pattern, is unlikely to be correctly classified in this genus.