Linnaeomyia Jaschhof & Jaschhof, 2015

Jaschhof, Mathias & Jaschhof, Catrin, 2019, New Dicerurini from Europe, mostly Sweden (Diptera: Cecidomyiidae, Porricondylinae), Zootaxa 4559 (2), pp. 245-264 : 249

Linnaeomyia Jaschhof & Jaschhof, 2015

The genus Linnaeomyia was recently introduced for L. hortensis , a species described from a single male found in a Malaise catch from Öland, southeast Sweden ( Jaschhof & Jaschhof 2015). Further Malaise trapping in the same area, only 500 m away from the type locality, has now provided another male of L. hortensis , which is used here for updating the original description. Furthermore, a series of male Dicerurini from the Czech Republic, assumed to belong to a new genus and provided for our study by Tomáš Sikora (University of Ostrava), on closer examination turned out to be a new species of Linnaeomyia , which is described and named here L. pratensis . All this new information is used for revising the generic diagnosis, as follows.

Diagnosis. Male morphology leaves no doubt on the affinity of Linnaeomyia with the tribe Dicerurini , within which it bears a faint resemblance to Neurepidosis ( Jaschhof & Jaschhof 2015) . There is no single unique structure or character that distinguishes Linnaeomyia , rather it is several characters in combination that are significant, as follows. (1) The ejaculatory apodeme is vestigial, i.e. short, thin, and poorly sclerotized ( Jaschhof & Jaschhof 2015, figs 2, 4; this paper, Fig. 6 ), whereas it is a large, well sclerotized rod in most other Dicerurini . (2) The tegmen, which is basically an elongate tube, is slightly broadened towards the apex, before it suddenly narrows into a small, variously shaped appendix ( Jaschhof & Jaschhof 2015: fig. 4; this paper, Fig. 8 ); its texture is rigid rather than flexible and, in one of the species ( L. pratensis ), reinforced by sclerotization. (The tegmen, not the ejaculatory apodeme, seems to stabilize the aedeagus, a completely soft-membranous structure in Linnaeomyia .) (3) The medial bridges of the gonocoxae are modified to hold variously shaped processes or protuberances ( Figs 5–6 ). Much less pronounced modifications are known from other Dicerurini , where the medial bridges are bulged or angled in various ways. (4) The gonostylus consists of two lobes: a bulbous main lobe with setae, and a much smaller side lobe, whose surface is either glabrous ( Jaschhof & Jaschhof 2015: fig. 3) or microtrichose ( Fig. 6 ). The gonostylar apex (or the apex of the main lobe) bears either a tooth or dense, large microtrichia.

Figures

FIGURES 5–11. Linnaeomyia hortensis, male, holotype. 5: Gonocoxa, dorsal. Linnaeomyia pratensis, holotype, male. 6: Genitalia, ventral. 7: Fourth flagellomere, lateral. 8: Tegmen, ventral. Gardenforsia oelandica, male, holotype. 9: Genitalia, ventral. 10: Foredistitarsus, ventrolateral. 11: Fourth flagellomere, dorsolateral. Scales for 5–9, 11, 0.05 mm, for 10, 0.025 mm. Arrows refer to characters described in the diagnosis.