Page 1 - Lo Cascio_2015

Biodiversity Journal, 2015, 6 (2): 529–592 MONOGRAPH

Worldwide checklist of the island mutillid wasps (Hymenop-

tera Mutillidae)

Pietro Lo Cascio

Nesos, via Vittorio Emanuele 24, 98055 Lipari, Messina, Italy; e-mail: plocascio@nesos.org

ABSTRACT The family of Mutillidae includes 776 taxa among species and subspecies recorded for 311
islands worldwide, whose distribution is provided in the present checklist. A brief review of
some traits that characterize the insular faunas of these hymenopteran parasitoids is given.
The main constraints to the dispersal on islands are due to the apterogyny and the occurrence
of suitable hosts. Species richness is generally correlated with island size. Although probably
still underestimated, the greatest number of species is found on Sri Lanka (82), Borneo (77),
Madagascar (70) and Taiwan (61). Endemics are more than half (55%) of the whole insular
mutillids and are found mostly in the oceanic islands and in those that have undergone to
a long-time isolation. On the contrary, endemic genera are represented only on few islands
(Madagascar, Sri Lanka and, secondarily, New Guinea, Sulawesi and Canary).

KEY WORDS Hymenoptera; Mutillidae; islands of the world; checklist; biogeography.
Received 26.04.2015; accepted 21.06.2015; printed 30.06.2015

INTRODUCTION conspecific males (Manley, 1999) and molecular
analysis (Pilgrim & Pitts, 2006).
The family Mutillidae includes 210 genera Despite the uncertainty that still persists about
(Lelej & Brothers, 2008; see also Williams & Pitts, the amount of true species belonging to this fam-
2009; Williams et al., 2011; Brothers, 2012; Tu et ily, 428 (about 10% of those actually described),
al., 2014) and more than 4,300 species so far as well as 13 genera, are known to be exclusively
described. These latter are estimated to be about distributed on islands. That confirms once again
6,000 (according to Lelej & Brothers, 2008), but as the islands contribute disproportionately to the
their number is rather uncertain pending for further global biodiversity (Whittaker & Fernández-Pala-
investigations that could lead to establish several cios, 2006).
new synonymies, because many species, and even The occurrence of mutillids wasps on islands is
a few genera, are still known only for one sex. however constrained by two morphological and
The strong sexual dimorphism typical of the biological traits: i) the low dispersal ability of the
members of this hymenopteran family makes wingless females, and ii) their dependence on
indeed difficult the association between males finding of suitable hosts, because Mutillidae are
(mostly winged) and females (all apterous), that is parasitoids that develop mainly on immature stages
generally based on the direct observations of of other Hymenoptera (Brothers, 1989).
mating, although have been also used alternative Consequently, the number of species on the
methods such as live-caught females to attract islands presumably decrease with increase of their