Matskási István (szerk.): A Magyar Természettudományi Múzeum évkönyve 79. (Budapest 1987)

Vojnits, A.: Falces and clavulus, hitherto, disregarded parts of the male genitalia in Eupithecia species (Lepidoptera, Geometridae)

ANNALES HISTORICO-NATURALES MUSEI NATIONALIS HUNGARICI Tomus 79. Budapest, 1987 p. 179-184. Falces and clavuius, hitherto disregarded parts of the male genitalia in Eupithecia species (Lepidoptera, Geometridae)* by A. M. VOJNITS, Budapest A. M. VOJNITS: Falces and clavuius, hitherto disregarded parts of the male genitalia in Eupithecia species (Lepidoptera, Geometridae). — Annls hist.-nat. Mus. natn. hung. 1987 79: 179-184. Abstract — The falces, a peculiar structure originating bilaterally from the tegumen, and its clavate termination the clavuius, represent characteristic parts of the male genitalia in Eupithecia species. Besides the description of these two structures, all other parts of the male copulatory organ also discussed. With 27 photos on 3 plates. When surveying Iepidopterological literature, expecially works concerning Eupithecia species, one finds it rather striking that the several organs and parts are evaluated — defined and designated — in the most diverse fashion. Indeed no author has ever paid any attention to a special structure of the male copulatory organ, a part which is the best characteristic for the entire taxonomix group. Even if it is shown in the figures — by far not a general feature — it is nowhere discussed. In the following I propose to describe the structure in question, and to treat also the other parts of the male copulatory organ. Besides my own investigations, I refer mostly to Noth American authors. Uncus — The typical Eupithecoid uncus is a structure atop of a wider, triangular base of diverse length. Apically bifid** in the majority of the species, the characteristically beakshaped uncus is formed by a dorsally stronger and ventrally weaker sclerotized hook. Among the most frequent Palaearctic species such is the satryata-group. Though in most cases the dorsal part of the more robust one, the reverse situation also occurs (cf. the Palaearctic lariciata FRR., oxycedrata RMBR., and the Nearctic nevadata-group). The dorsal part can also be quite short and thus displaying a transition towards the uniapical type. In the species representing the long type of the uniapical type, the apex of the uncus is strong (the Palaearctic denticulata TR., centaureata DEN. et SCHIFF., and the Nearctic palpata PACKARD as well as the mutata-gvoxxp). A medium long uncus, as compared to the entirety of the genitalia varies between very squat (homogrammata DIETZE) and very slender (lanceata HBN.). A special group, composed of the mainly East Palaearctic species, e.g. fragmentaria VOJNITS, acerba VOJNITS, which displays an uncus which is basically nothing more than a wide and flat, distally incised plate. The uncus of a Nearctic species (coloradensis HÜLST) is short, membranous, a nearly mdimentary structure. Tegumen — A largely triangular formation, extending from the uncus to the conjointment of the valvae and the vinculum, its base varying and its lateral sides subtending diverse angles, rounded above and there bearing the uncus. Its width as well as its height rather variable, and it apparently lacks any feature applicable for classification or identification of the species. Its apparent shape depends largely on dissection technique and imbedding on the slide. *Thc genitalia of Eupithecia species I. The male copulatory organ. **A good example of terminological difficulties: there are two kinds of double uncus: with two separate branches (in Melticta, Rhopalocera), or single-branched but biapical (bifid) owing to a suture. However, the bifid one is often "translated" as "double-branched". In addition, the bifid uncus is termed "hooded" in American literature.