Winnertzia tridens Panelius

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 : 58-59

Winnertzia tridens Panelius

Figs 103–105

Winnertzia tridens is understood here in the sense of Panelius (1965: fig. 33d) who depicted the antennal sensilla of the male, which are unmistakable.As Panelius’s study material comprised only a single series of 10 male specimens, which F.W. Edwards had collected in England, he was apparently unaware of the fact that W. tridens is but one of several species with largely similar morphology. Spungis (1992), who had many more specimens from various geographic regions available for study, was first to notice the identification problems posed by the W. tridens complex. Although he was able to distinguish among five different morphotypes ( Spungis 1992: figs 48–52, with fig. 48 depicting the genuine W. tridens ), he considered the diversity he had found to reflect extreme intraspecific variability. In our earlier revision of Swedish Winnertzia ( Jaschhof & Jaschhof 2013: 104 ff.) we followed his opinion, recognizing that specimens from Sweden are similarly variable. Now, after careful reexamination of the morphology of more than 400 males from all over Sweden, we have reason to change our mind and treat as discrete species what previously appeared to be morphological varieties of W. tridens . Using male morphological criteria we can distinguish among six species: the genuine W. tridens , W. feralis Mamaev (possibly depicted by Spungis 1992: fig. 52), two new species described here as W. hamatula (possibly identical with Spungis 1992: fig. 51) and W. longicoxa (depicted by Spungis 1992: fig. 49), and two species left unnamed here, which are discussed under W. feralis . Our data prove that these species frequently co-occur, with a maximum of five found in the same locality.

Diagnosis. Males of W. tridens are medium size, brown, and have 12 long-necked flagellomeres, which are properties pertaining to closely related species also. A peculiarity is that the translucent antennal sensilla of W. tridens are irregularly branched in varied ways, the branches being unusually long and occasionally cross-linked ( Figs 104–105 ). These sensilla are present on all flagellomeres, including the apical one, which is unusual among Winnertzia . The genitalia of W. tridens , which were repeatedly depicted in the literature ( Panelius 1965: fig. 33c; Spungis 1992: fig. 48; Jaschhof & Jaschhof 2013: fig. 47A), are so similar to that of W. feralis that both species are virtually indistinguishable in this respect―an exceptional situation in mycophagous Cecidomyiidae . The empodia of W. tridens are maximally one third as long as the claws ( Fig. 103 ), which is another distinction vis-á-vis W. feralis in which empodia and claws are equally long.

Distribution in Sweden. All our specimens, a total of 118 males, come from the southern half of Sweden (Skåne to Uppland). In that, the distribution of W. tridens matches that of W. feralis , and both species were found co-occurring at the same sites.

Material studied. Specimens listed by Jaschhof & Jaschhof (2013) under the following numbers: SE1663, SE1669–SE1670, SE1674, SE1692–1693, SE1715, SE1742, SE1748, SE1761–SE1762, SE1765–SE1768, SE1778–SE1780, SE1786, SE1789, SE1802–SE1811, SE1828, SE1833, SE1851, SE1859–SE1872, SE1874– SE1876, SE1878–SE1879, SE1883–SE1885, SE1887–SE1889, SE1891, SE1893–SE1900, SE1903–SE1907, SE1909–SE1914, SE1917–SE1927, SE1931–SE1941 (all in NHRS), SE1781 , SE1877 , SE1880 – SE1882 , SE1886 , SE1908 , and SE1928 (all in SDEI); further specimens as follows. Sweden: 1 male, Öland, Borgholm, Skepparsäng NR, dry pine forest, 11 June–21 July 2015, MT, MCJ (spn CEC3120 ) ; 2 males, Öland, Mörbylånga, Skogsby lund NR, mixed broadleaf forest, 10 June–14 July 2015, MT, MCJ (spns CEC3118 – CEC3119 ) ; 1 male, Östergötland, Ödeshög, Omberg, Storpissan NR, 8 June–26 July 2010, MT, MCJ (spn CEC3121 ) ; 3 males, Uppland, Håbo, Biskops-Arnö, elm grove, 18 June–4 July 2003, Malaise trap, Swedish Malaise Trap Project (trap 8, collection event 389) (spns CEC3126 – CEC3128 ); 1 male, same data but 15–28 June 2004 (collection event 1557) (spn CEC3122 ); 2 males, same data but 28 June–13 July 2004 (collection event 1558) (spns CEC3123 and CEC3125 ) (all in SDEI) .

Figures

FIGURES 100–105. Male morphology of Winnertzia feralis (100–102) and Winnertzia tridens (103–105). 100: Fourth flagellomere, lateral, specimen from Uppland. 101: Ditto, medial. 102: Acropod, lateral, specimen from Östergötland. 103: Ditto, specimen from Öland. 104: Fourth flagellomere, lateral. 105: Ditto, medial. Scales for 100–101 and 104–105, 0.05 mm; for 102–103, 0.025 mm.