Winnertzia setosa, Jaschhof & Jaschhof, 2020

Jaschhof, Mathias & Jaschhof, Catrin, 2020, Reevaluation of species richness in Winnertzia (Diptera, Cecidomyiidae, Winnertziinae), with descriptions of 37 new species from Sweden, Peru and Australia, Zootaxa 4829 (1), pp. 1-72 : 25-26

Winnertzia setosa group

Diagnosis. This group is introduced here for species sharing three or more of the following similarities: the gonostylar claw is long, mostly narrow and, as a rule, exposed at or near the gonostylar apex; of the gonocoxites, the U-shaped emargination is surrounded by conspicuously large setae, the dorsal apodemes are short, and the dorso-posterior portions are not extended; the tegminal flaps are mostly distinct and occasionally microtrichose; and the spikes on the aedeagal bulge are unusually small. Several of the species classified in this group have broad, roundish wings and / or lack vein M 4. The tarsal claws have almost always a single, large tooth basally.

Phylogeny. Although the included species resemble each other closely, we are not entirely convinced that the setosa group is monophyletic Our suspicion comes from the fact that none of the derived character states found in this group is shared by all its members. A good example here is the absence of vein M 4, a condition unknown to occur in Winnertzia outside the setosa group. The four species in Sweden lacking M 4 ( W. ekdalensis , W. grytsjoenensis , two unnamed species) are not homogenous in other morphological features but blend in well with those species in which M 4 is present. This observation is important insofar as Felt (1920) had introduced a discrete genus, Parwinnertzia , for a Winnertzia -like female from North America whose only distinction is the lack of M 4. As is now obvious, this condition should not be used as a generic character. Parwinnertzia is thus synonymized here with Winnertzia , and the two species previously classified in that genus, P. notmani Felt and P. italiana Mamaev & Zaitzev , are recombined accordingly. Another reason to be uncertain about the monophyly of the setosa group is that some of the included species show characters whose principal occurrence is in the globifera group. For example, the aedeagal apodeme of W. grytsjoenensis is markedly swollen above the solid basal portion ( Fig. 50 ), and the gonostylar claw of W. setosa is in a subapical rather than apical position ( Fig. 59 ).

Species included. The setosa group is established for six species newly described here, including the eponymous W. setosa , and for the two species previously classified in Parwinnertzia , the Nearctic W. notmani comb. nov. and the Palearctic W. italiana comb. nov. Our material from Sweden contains another seven species belonging to this group, which we do not treat in detail here because the specimens at our disposal, in each case singletons, are not in a proper condition.

Remarks. A likely explanation why the setosa group has not been detected earlier (in spite of its many members) is the fact that specimens of the included species are rarely found. Of the 13 species known to occur in Sweden we have seen only 24 specimens in total, all but two specimens found in Malaise trap samples. This shows to what extent survey work on Winnertzia depends on Malaise trap material.

Figures

FIGURES 48–53. Male morphology of Winnertzia grytsjoenensis (48–50) and Winnertzia normalis (51–53). 48: Fourth flagellomere, lateral, holotype. 49: Ditto, medial. 50: Genitalia, ventral, holotype. 51: Ditto. 52: Fourth flagellomere, lateral, paratype. 53: Ditto, medial. Scales 0.05 mm. Arrows refer to characters described in the diagnoses.

FIGURES 54–62. Male morphology of Winnertzia oelandica (54–57) and Winnertzia setosa (58–62). 54: Fourth flagellomere, lateral, paratype. 55: Ditto, medial. 56: Genitalia, ventral, holotype. 57: Basitarsus of foreleg, lateral, holotype. 58: Posterior portion of ninth tergite, dorsal, holotype. 59: Genitalia, ventral, holotype. 60: Fourth flagellomere, lateral, holotype. 61: Ditto, medial. 62: Dorsal gonocoxal bridge, ventral, paratype. Scales for 54–57 and 59–61, 0.05 mm; for 58 and 62, 0.025 mm.Arrows refer to characters described in the diagnoses.