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Boll. Soc. Entomol. 136/3 29-11-2004 17:56 Pagina 241

Mutillid wasps of the Italian minor islands 241

Schembri, 1983; Petersen, 1988). It was reported as parasitoid of Hymenoptera An-
tophoridae and Megachilidae (Ferton, 1896; Skorikov, 1935; Invrea, 1964), which were
frequently observed on the islands under consideration (P. Lo Cascio, pers. obs.). On
the contrary, R. ghilianii was never recorded on any islands outside the Italian ones, and
its biology is still unknown. Lack of detailed ecological and biological data about these
species does not allow to consider them as true “insular specialists”. In fact, both seem
to be common and widespread also in continental areas and in main islands. Moreover,
because of their showiness and large size (at least among the species occurring in the
Mediterranean area), the possibility of their relative over-abundance among the mate-
rial collected by non-specialists should not be excluded, while more elusive and/or smaller
species could have been easily neglected during the same samplings.

Finally, it is noteworthy to stress the occurrence of Ronisia barbara on Isola dei Conigli
that is the smallest island (0,044 Km2) on which Mutillid wasps have been recorded. Due
to the high concentration of the Mediterranean yellow-legged gull, Larus cachinnans Pal-
las, the soil of this islet results characterised by strong level of eutrophication, acidification,
and nutrient imbalances, revealed also by the abundance of nitrophilous plant species (P.
Lo Cascio, pers. obs.). From an ecological point of view, it should be noted that R. bar-
bara shows a high degree of tolerance to the above factors, which generally constitute
severe limitations for several invertebrates on small insular environments.

ACKNOWLEDGEMENTS

We thank Dr Roberto Poggi and Dr Luca Bartolozzi, who kindly consented the study of
the collections kept, respectively, at the Museo Civico di Storia Naturale “G. Doria”, Genoa and
at Zoological Section “La Specola”, Natural History Museum of the University of Florence. Many
friends and colleagues, who communicated of several data from their collections or collaborat-
ed during the fieldwork carried out on several Italian minor islands, have made the present research
possible: to all of them we express our sincerest gratitude. Finally, we thank Dr Simona Barresi
for drawing the of map Italian islands; Prof. Attilio Carapezza for the language revision of the
manuscript; Dr Maurizio Pavesi and an anonymous referee, for their useful suggestions.

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