New records of two rare neuropterans (Insecta: Neuroptera) in Slovenia

Two neuropteran species, the antlion Neuroleon microstenus (McLachlan 1898) and the mantispid Mantispa aphavexelte Aspöck & Aspöck 1994, are known as extremely rare in Slovenia. New records of the species are presented. Both neuropterans occur only in the Submediterranean region of the country. Due to the insufficient knowledge of its ecology, the threat status of M. aphavexelte is unknown, whilst N. microstenus should be considered as endangered considering that its habitats are shrinking.


Introduction
Neuroptera of Slovenia are still insufficiently investigated. There are some 100 species known from the country (Devetak 1992 and unpublished data). Two species, the antlion Neuroleon microstenus (McLachlan 1898) and the mantispid Mantispa aphavexelte Aspöck & Aspöck 1994, are considered extremely rare in Slovenia.
In 1990, M. aphavexelte was recorded for the first time in Slovenia (Devetak 1995).
Knowledge of the species' ecology is poor and it was believed to be an extremely rare neuropteran. During the field studies carried out in the Submediterranean region of Slovenia in the recent years it has been revealed, however, that the species is not as rare as expected.
Neuroleon microstenus was found in Slovenia in 2001 (Devetak & Devetak 2004). Only scarce information is available on the biology of the species. It is a polycentric Mediterranean species (for review of its distribution see Aspöck et al. 2001). Morphology of the first instar larvae was described by Gepp (1974). It is a non-pit-building antlion species. Adults can easily be distinguished from other Neuroleon species following key-characters (Aspöck et al. 1980).
Among the other characters, abdomen of males is much longer than the wings. Characteristic are also two dark pigmented spots in forewings. The only known finding-place of N. microstenus in Slovenia was destroyed in 2003, and consequently the species was considered to be extinct in Slovenia. In 2005, however, the occurrence of the species in the country was re-confirmed. Documentation of the recent records is presented in this paper.

Material and methods
Individuals were collected with sweep-net, and fluid-preserved specimens are deposited in Dušan Devetak's collection (Maribor). The nomenclature of the determined neuropterans follows Aspöck et al. (2001).
Ecology: The adults were collected in a grassland (near Izola and Sečovlje) and on eroded flysch slopes (Hrastovlje and Črni Kal).

Discussion
The genus Neuroleon Navás, 1909 includes small non-pit-building antlions and is confined to Africa, southern Europe and large parts of Asia (Hölzel 1986). There are about 120 valid species of the genus, but only two of them occur in the western part of the Balkan Peninsula (Devetak & Devetak 2004).
Knowledge of ecology and distribution of Neuroleon species is poor; usually, only single animals have been collected in European countries. The only exception in this respect is France, where ecology and distribution of the genus was studied in detail by Steffan (1971).
According to Aspöck et al. (1980), the typical habitats of the species are forests or macchia. My findings, however, do not confirm this statement. In Slovenia, N. microstenus populates habitats devoid of trees and bushes. In Hrastovlje and Črni Kal, a great number of adults was observed flying on dry eroded flysch slopes.
In 2003, the only known locality of N. microstenus at Srmin was destroyed, when the material excavated during road construction was deposited at this locality and the eroded flysch slopes were filled up. However, typical habitats of the species are endangered due to natural reforestation of grassland ecosystems. Reforestation is a phase of natural process of succession.
Despite the fact that in Slovenia M. aphavexelte is distributed only in its Submediterranean region, it is not considered an endangered species. In some places, like Kastelec, it occurs sympatrically with M. styriaca.