Gardenforsia, Jaschhof & Jaschhof, 2019

Jaschhof, Mathias & Jaschhof, Catrin, 2019, New Dicerurini from Europe, mostly Sweden (Diptera: Cecidomyiidae, Porricondylinae), Zootaxa 4559 (2), pp. 245-264 : 262

Gardenforsia gen. nov.

The genus Gardenforsia is founded here for G. oelandica , a new species discovered recently in Malaise catches from Öland. Two specimens in our collection from Uppland, too poorly preserved for taxonomic description at this stage, give evidence of even another species of Gardenforsia in Sweden. Gardenforsia is another example of regressive morphology in Dicerurini (see Jaschhof & Jaschhof 2013: 108). Characters of males (females are unknown) suggest G. oelandica to be close to Desertepidosis or Neurepidosis , but the definitions of those genera would require undue extension in order to absorb the new species. It is therefore placed in a genus of its own, with the following characters.

Diagnosis. Characters such as circumfila with posterior extensions ( Fig. 11 ) and parameral apodemes forming wide, single-branched crescents ( Fig. 9 ) place Gardenforsia in the tribe Dicerurini where it belongs to the group of genera with spineless basitarsi ( Jaschhof & Jaschhof 2013: 108ff.). The extent of morphological regression in Gardenforsia and Desertepidosis is similar, manifested by the following characters: the eye bridge lacks dorsal ommatidia; flagellomeres number 13; circumfila are present on the first to eighth flagellomeres only; and the narrow wings lack M 1+2, while M 4 is vestigial. A peculiarity found in Gardenforsia is that the distitarsus of the foreleg has a double row of short, blunt-ending bristles ventrally ( Fig. 10 ), which to our knowledge are present in no other dicerurines. The genitalic structures of male Gardenforsia are as simple as in Desertepidosis , but, unlike in that genus, the gonostylus is broad and flattened ( Fig. 9 , ↓ 7), not subcylindrical ( Figs 1–2 ), and the tegmen is a broad plate ( Fig. 9 , ↓ 8) rather than a slender tube ( Figs 1–2 ).

Etymology. In naming this new genus Gardenforsia , we honor Ulf Gärdenfors, emeritus professor of conservation biology at the Swedish University of Agricultural Sciences, Uppsala, for his relentless commitment for the exploration and preservation of biodiversity, both in Sweden and beyond. We particularly acknowledge his merits as co-founder of Svenska artprojektet, The Swedish Taxonomy Initiative, and, for many years, deputy director of ArtDatabanken, The Swedish Species Information Centre.

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.

FIGURES 1–4. Desertepidosis grytsjoenensis, male, holotype. 1: Genitalia, ventral. Desertepidosis robusta, males. 2: Genitalia, ventral, holotype. 3: Base of ejaculatory apodeme, ventral, paratype. 4: Apex of wing, dorsal, holotype. Scales for 1– 3, 0.05 mm, for 4, 0.25 mm. Arrows refer to characters described in the diagnosis.