Contributions to Zoology, 73 (4) (2004)Andrea Grill; Rob de Vos; Jan van Arkel: The shape of endemics: Notes on male and female genitalia in the genus Maniola (Schrank, 1801), (Lepidoptera, Nymphalidae, Satyrinae)

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Introduction

“Made up of concave and convex hills and valleys”, was one of the first descriptions of the genital structure of a male Meadow Brown, Maniola jurtina (L.), meant to emphasize that this species’ genitalia are very irregularly shaped for a Satyrid (Muschamp, 1915). Since then, geographic variation in genital morphology of the Meadow Brown has been extensively discussed (Thomson, 1973, 1976; Goulson, 1993). In recent decades, two new Maniola species have been described (Thomson, 1987, 1990). First, the island endemic, Maniola chia Thomson, 1987, whose distribution is restricted to the Greek island of Chios. Second, Maniola halicarnassus Thomson, 1990, which flies on the Bodrum peninsula (Turkey) and the Aegean island of Nissiros. Maniola nurag (Ghiliani, 1852) is endemic to Sardinia, and a third endemic has been described from the island of Cyprus, Maniola cypricola (Graves, 1928)(for distribution areas of species see Fig. 1). Maniola megala (oberthür, 1909) occurs on the Greek island of Lesbos, throughout southern Turkey and in Iran.

FIG2

Fig. 1. Distribution areas of the six European species of the genus Maniola: (A) Maniola halicarnassus, (B) M. telmessia, (C) M. nurag, (D) M. chia, (E) M. cypricola, (F) M. jurtina.

Although neighbouring islands would be in flight distance for all island endemics, the ranges of the island-Maniola species are well confined to the borders of the respective island. In Chios, M. chia is said to entirely replace M. jurtina and Maniola telmessia (zeller, 1847), species that are commonly found on the neighbouring islands and the Turkish mainland, which is only a few kilometers distant from Chios. In Sardinia, on the other hand, M. nurag flies sympatrically with M. jurtina. Although, the latter species is usually concentrated on the coast, whereas the Sardinian endemic has its distributional centres in the mountain areas of the island (> 500 m), there is a zone of overlap at intermediate altitudes (500 – 900 m), where both species fly contemporarily at the same sites (Grill, 2003).

Butterflies of the genus Maniola are known for their large morphological variation (Fig. 2), at inter- as well as intraspecific level, on both local and continental scale (Ford, 1945; Thomson, 1973). Given the overlap in wing-patterns, habitat selection, and geographic distribution of various Maniola species, genitalia morphology is sometimes the only possibility to tell specimens apart. What is more, genitalia shapes can also much vary within a single species (Thomson, 1973). Nevertheless, the species status of M. chia and M. cypricola has been justified mainly because of differences in the form of the male genitalia; in wing-patterns they resemble M. jurtina and M. telmessia, respectively. For the third endemic species in this genus, M. nurag, genitalia structure and shape has never been described and illustrated in detail as yet.

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Fig. 2. Variation in wing pattern in the genus Maniola. All the specimens are in the collection of the Zoological Museum Amsterdam. Column (a) shows the upperside, (b) the underside of the butterflies.

FIG2

Schematic drawing of the butterflies in Fig. 2 . Legend: 1. M. jurtina France (male), 2. M. jurtina France (female), 3. M. jurtina Sardinia (male), 4. M. jurtina Sardinia (female), 5. M. telmessia (male), 6. M. telmessia (female), 7. M. nurag (male), 8. M. nurag intermediate form (male), 9. M. nurag (female), 10. M. chia (male), 11. M. chia (female), 12. M. halicarnassus (male), 13. M. halicarnassus (female), 14. M. cypricola (male), and 15. M. cypricola (female).

In this paper, the genital apparatus of M. nurag is described and illustrated in detail for the first time. We further describe two Sardinian individuals, whose genitalia seem to be intermediates between M. nurag and M. jurtina. The genitalia morphology of these Sardinian specimens is compared to the shape and structure of the genital organs in all other Maniola species, except M. megala, as this species can be unequivocally distinguished from its congenerics by its appreciably larger size, and the wing underside markings.

Ergo, the three main questions we address in this paper are:

1) Are there diagnostic characters in the genitalia of the different Maniola species?

2) What is the position of the Sardinian intermediate individuals in the genus Maniola?

3) Is species status justified for M. chia and M. cypricola?