S. Mahunka szerk.: Folia Entomologica Hungarica 61. (Budapest, 2000)

timitratus (Rejtő). The asexual generation induce galls on Q. petraea, Q. robur, and Q. humilis (= pubescens). Quercus suber as a host plant was also recorded by Kieffer (1897-1901) and Cabrera (1897) but it must be a host plant misidentification because no records of A. dentimitratus on this oak species have been found since, even from localities where from the original records of the species are. Another host oak, Q. ilex, mentioned by Houard (1908) is also mistakable and was taken from Kieffer 's original record. Females of the sexual generation of Andricus dentimitratus were experimentally obtained but are not described yet (Pujade-Villar 1994a). The adult wasps of the "kollari" group, which this species belongs to, morphologically are very homogeneous. For this reason, a precise description of the sexual generation of A. dentimitratus requests more material, especially males and galls (Pujade-Villar 1994a). No doubts, that the sexual generation of A. dentimitratus is not identical with Andricus floridus Tavares as was stated recently by Melika and Csóka (1998), thus A. floridus remains as a valid name and species. Andricus floridus morphologically closely related to Andricus amend Giraud, and A. glandulae (Hartig) (= xanthopsis Schlechtendal) (Pujade-Villar 1991, PujadeVillar et al, in prep.). Andricus quercustozae (Bosc, 1792) and Andricus kiefferi (Cabrera, 1897) Cabrera (1897) described a new gall wasp species from the Iberian Peninsula, Cynips kiefferi, on the basis of the asexual female. Later, it was transferred to the Andricus genus (Benson 1953). The description and the drawing of the gall was given in Kieffer (1897-1901). The species was also recorded from Sicily (Italy) (Kieffer 1897-1901, Dalla Torre and Kieffer 1910). However, since then, this species has not been found. The examination of the type material of Andricus kiefferi (by Juli Pujade-Villar at the MNCN of Madrid, Spain in 1995), showed no differences in the morphology of adult wasps of Andricus kiefferi and Andricus quercustozae (Bosc, 1792). On the other hand, A. kiefferi gall, despite its similarity to A. quercustozae, presents also some characters of Andricus dentimitratus (Rejtő) gall. Such a similarity in the gall form can be explained by the next mechanism. A floral bud at its early developmental stage can be attacked simultaneously by the bisexual females of both species, A. quercustozae and A. dentimitratus. As a result, A. quercustozae gall can fully develop but the gall shape is deformed and bears certain peculiarities which are typical for the second gall-inducer, A. dentimitratus. Such a gall deformation caused by the above-mentioned mechanism is not rare. Wachtl, according Kieffer (1897-1901: 477), also gave some examples for different Andricus species. It has been also observed by authors, for Andricus coriarius (Hartig, 1843) and A. mayri (Wachtl, 1879) in the Iberian Peninsula. Also the competition between cynipids could be intense at a high population densities, and in some species, for example, in A. kollari, A. dentimitratus, etc., could lead to the formation of double or triple galls (Marsden-Jones 1953, Pujade-Villar, peri, obs.), or two or more species may compete for "enemy-free" space (for example, Andricus kollari and A. lignicolus) (Schönrogge et al 1994, 1998). However, this process is not a real reproductive "hybridisation" between two different gall wasp species. The result is a "mixed", abberant and deformated gall that forming when two or more galls develops very closely inside one bud. On the other hand, possibility of a real "hybridisation" between two closely related bisexual forms in the "kollari" group of Andricus genus was demonstrated by Folliot (1964) for A. kollari and A. lignicolus. This fact has been proved under laboratory conditions only but never in nature. Nevertheless, we can not discard it.