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566 PIETRO LO CASCIO

FAUNAL AND BIOGEOGRAPHICAL OUT- Mediterranean islands that generally lie near to
LINES the mainland or, such the rather isolated Sardinia
and Corsica, represent fragments of continental
The records of Mutillidae on islands concern landmass (Advokaat et al., 2014).
774 among species and subspecies (including 8 Except for the cases above mentioned, the fe-
identified at generic rank), equal to about 18% of males may expand the range of dispersal through
those currently accepted as valid. Of course, this the phoretic copulation, and Mutillidae have col-
number is provisional, because many islands are on-ized remote insular groups such as Solomons
still unexplored or their faunal knowledge cannot (Mickel, 1935; 1937; Krombein, 1971), New Cale-
be considered as exhaustive. For instance, accord- donia (André, 1896a; Brothers, 2012), New Zea-
ing to Brothers (2012) the fauna of New Caledonia land (Valentine & Walker, 1983), Ogasawara
includes 4 species so far described, but also a large (Yasumatsu, 1936), Palau (Esaki, 1938), Vanuatu
number (probably 14 more) not yet identified; and (Brothers, 2012) and, in the other side of the Pa-
Portuondo Ferrer & Fernández-Triana (2003) es- cific, the Galápagos (Williams, 1926). Some of
timated the probable occurrence of 16 species on them belonging to ancient continental landmasses,
Cuba, where hitherto only 11 have been recorded. although characterized by long-term isolation (e.g.
The same is also strongly suggested by the note- New Caledonia), but others have indeed volcanic
worthy discrepancy between the number of species origin and have never been connected to the
known for Sicily (42) and for New Guinea (36), a neighboring mainland. Vanuatu, that lies 1,900 Km
tropical island thirty times larger and moreover con- far from Australia, represents a remarkable case of
sidered one of the global biodiversity hotspots. isolation, although the sea barrier between these
Despite this gap in knowledge, on the basis of islands and the nearest continent is interrupted by
the data provided in the checklist is anyhow pos- intermediate steps (New Caledonia); is not by
sible to delineate an overview of the main biogeo- chance that the only species found on Espiritu Santu
graphical features of the island faunas, which are belongs to the genus Ancistrotilla Brothers, 2012,
briefly discussed in the following paragraphs. the same occurring on New Caledonia and whose
distribution is also extended to Australia and New
Dispersal Guinea (Brothers, 2012).
Conversely, Kuhlmann (2006) has high lighted
As already stated in the Introduction, the main the rapid loss of Mutillidae as well as other groups
limits to the dispersal of Mutillidae on islands are of parasitic Hymenoptera eastwards of Melanesia,
related to some traits of their natural history, and while Zimmermann (1942) and Williams (1947)
primarily to the apterogyny. This would be indir- remarked the lack of this family on large archipela-
ectly supported by the fact that several genera goes such as Polynesia, Hawaii, and most part of
whose males are also wingless, such as the Oriental Micronesia (see also Krombein, 1949a). The same
Ticoplinae Cameronilla Lelej in Lelej & Krombein, has been observed by Beqtaert (1929) for the
2001 and Hindustanilla Lelej in Lelej & Krombein, Archipelago of Bermuda (N-Atlantic), as confirmed
2001, or the Afrotropical Sphaeropthalminae also by more recent surveys (see Hilburn et al.,
Brachymutilla André, 1901 and Apteromutilla 1990).
Ashmead, 1903, are fully absent on oceanic islands. While the absence of mutillids is then rather
Sri Lanka is inhabited by the endemic monospecific understandable for these extremely remote islands,
genus Indratilla Lelej, 1993 as well as by some as well as for Bermuda, Azores and St. Helena in
species of Spilomutilla Ashmead, 1903 with males the Atlantic, Chagos, Seychelles and Mauritius in
apterous or having rudimentary wings (Lelej, 1993, the Indian Ocean, it is not so easily explained for
2005), but this island is geologically part of the other less distant from the continental landmasses:
Indian subcontinent and was in land connection for instance, Fernando de Noronha (370 Km),
to mainland India during the Pleistocene sea-regres- Madeira and Cape Verde (both around 600 Km) in
sions (Voris, 2000). Also, the Myrmillinae Blakeius the Atlantic, or Lord Howe (750 Km) in the Pacific.
2
chiesii (Spinola, 1839), B. leopoldinus Invrea, 1955 This latter, despite its very small area (<15 Km ),
and Myrmilla capitata (Lucas, 1846) are found on is inhabited by 225 species of parasitoids and