1 Natural History Museum of Denmark, Natural History Museum of Denmark, Faculty of Science, Københavns Universitet2 Lithuanian Entomological Society3 Natural History Museum of Denmark, Natural History Museum of Denmark, Faculty of Science, Københavns Universitet
Differences in the male genitalia ensure a safe identification of Zygaena (Zygaena) trifolii (Esper 1783) and Zygaena (Zygaena) lonicerae (Scheven 1777) Zygaena (Zygaena) trifolii (Esper 1783) and Zygaena (Zygaena) lonicerae (Scheven 1777) are similar species with partially overlapping distribution areas in Denmark. In some cases it is hard to distinguish the two from external features only, especially if there is no information on the habitat, as both species exhibit major variation in size, colouration and shape (figs 1-10). While studying the material of these two species in collection of the Zoological Museum of Copenhagen (ZMUC) we found some useful and reliable differences in male genitalia structures that can be used for identification of these species. In most literature dealing with these two species no figures are given of the (male) genitalia (e.g. Tremewan, 1986; Hofmann, 1994; Top-Jensen & Fibiger, 2009), or only some line drawings of these structures are presented. Thus, Naumann et al. (1999) only illustrate the uncus, but unfortunately we do not find the differences indicated in the characters in question (which may often be observed without dissection, just after light brushing of scales/hairs) to be reliable. We found that the main diagnostic characters are in the phal-1131325 Indhold Lepidoptera_10_5.indd 186 30/05/13 10.13 Lepidoptera bind X, nr. 5, 2013 187 lus. The most distinct differences that can be seen are in size and shape of dorsal plates of phallus (aedeagus) (figs 19-26), in the general size of phallus, and in shape and size of the everted vesica (figs 27-34). The main difference that is usually noted in the literature is the shape of the ventral plate of phallus and the way the spines are distributed on that plate: they are longer and stronger in Z. lonicerae, smaller and more compactly arranged in Z. trifolii (e.g. Leraut, 2012). As can be seen from figures 11-18 this difference is not very clear and may lead to misidentification. We have not found any comparison of the size of phallus or of the shape of vesica of these species in the literature, so we trust this contribution will help to identify them more reliably. In Denmark Z. trifolii is distributed throughout Jutland (uncommon in northern Jutland). It has also been found in Funen, but there are no records from that island since 1975. Z. lonicera is more widely distributed in Denmark, although it is only known from few localities in western and northen Jutland, southern Zealand and on Lolland, Falster and Møn (Kaaber, 1982; Stadel Nielsen, 2005). Our study confirmed this distribution - although we found a number of misidentified specimens in the collection of ZMUC. We found a single specimen of Z. trifolii labeled »Fortunen« (north of Copenhagen), but we consider it to be mislabelled.
Lepidoptera, 2013, Vol 10, Issue 4, p. 182-187
Det Naturvidenskabelige Fakultet; Male genitalia; everted vesica