53
Correspondence
All articles available online at http://www.salamandra-journal.com
© 2010 Deutsche Gesellschat für Herpetologie und Terrarienkunde e.V. (DGHT), Rheinbach, Germany
SALAMANDRA 46(1) 53–54 20 February 2010 ISSN 0036–3375
Correspondence
Wasp predation on Malagasy frog egg clutches
Goran Safarek
1
, Olga Jovanovic
2
, Miguel Vences
2
, Hellmut Kurrer
3
,
James M. Carpenter
4
& Rainer Dolch
5
1)
Trg kralja Krešimira 10, 48000 Koprivnica, Croatia
2)
Division of Evolutionary Biology, Zoological Institute, Technical University of Braunschweig, Spielmannstraße 8,
38106 Braunschweig, Germany
3)
Am Wall 3, 23879 Mölln, Germany
4)
Division of Invertebrate Zoology, American Museum of Natural History, Central Park West at 79
th
Street, New York,
NY 10024, USA
5)
Association Mitsinjo, Lot 104 A Gare, Andasibe 514, Madagascar
Corresponding author: Olga Jovanovic, e-mail: olgajo@tu-bs.de
Manuscript received: 22 June 2009
Besides their great species diversity, Malagasy anurans ex-
hibit a wide array of behavioural patterns, including di-
verse reproductive behaviour. hey display different re-
productive modes (Glaw & V ences 2007) out of 29 rec-
ognized across the world (Duellman & Trueb 986). he
clutches reported here belong to the reproductive mode
that comprises arboreal eggs deposited on vegetation over-
hanging ponds or swamps (mode 8 according to Duell-
man & Trueb 986) into which hatching tadpoles drop.
In Madagascar, most species of the genera Blommersia
and Guibemantis use this reproductive strategy (Glaw &
Vences 2007) which may represent an antipredatory be-
havior (Orians & Janzen 974) or might simply be related
to the arboreal habits of these frogs. Being static, frog eggs
have limited options for defense, compared with older and
much more agile life stages like tadpoles or froglets (Chiv-
ers et al. 200). Eggs therefore suffer high levels of preda-
tion in the water. Most arboreal egg clutches are deposited
on flimsy leaves or branches so that the majority of ver-
tebrate predators are discouraged from reaching them, al-
though they may be preyed upon by snakes and insects.
One such predation event was observed on egg clutches
of Guibemantis, a genus of mantellid frogs from Madagascar.
he clutch was preyed on by a wasp on 2 February 2007 in
the morning hours, during warm, humid and mostly cloudy
weather with sunny and rainy spells (rainy season in Mada-
gascar) in the Station Forestière d’Analamazaotra (tropical
rainforest nature reserve, managed by Association Mitsin-
jo) near Andasibe village ( 8°56.43’S, 48°24.879’E, 94 m
above sea level, taken by GPS receiver). A wasp of the ge-
nus Ropalidia was flying around several clutches attached to
palm leaves and hanging above the small pond in the Orchid
Park. It tried on several occasions to get into the gelatinous
clutch (Fig. a), and then stuck its head into it (Fig. b). he
wasp grasped the first embryo and pulled it out of the gelati-
nous mass, then placed it on a branch and consumed it (Fig.
c). Aterwards, the wasp stacked several embryos on the
branch before starting to eat them. he embryos in the egg
clutch were seen moving away slightly from the predator.
At the Station Forestière d’Analamazaotra, two frog
species were observed in February 2008 depositing eggs
on the leaves overhanging the pond in the Orchid Park:
Guibemantis liber and G. tornieri. Eggs from most of the
frog clutches were identified using DNA barcoding, a
rapid molecular technique that has shown reliable results
in amphibian species identification (V ences et al. 2005).
We used a fragment of the mitochondrial 6S rRNA gene
(Genbank accession numbers GQ24454 and GQ24455)
that is known to be sufficiently variable among species of
amphibians (Vences et al. 2005). Based on comparison of
morphology and colouration with the barcoded clutches,
we presume that the embryos depredated by the wasp in
2007 were those of G. tornieri.
In Madagascar, predation on frog egg clutches depos-
ited outside of water hitherto has been recorded only for a
few snakes (e.g. some species of the genus Compsophis, es-
pecially C. laphystius; see photos in Glaw & V ences 2007),
and never by wasps. he observed wasp preying on these
clutches has been deposited in the American Museum of
Natural History, New York, and is still awaiting final deter-
mination by J.M.C. and J. Kojima who are preparing a re-
vision of the Malagasy genus Ropalidia. According to these
unpublished data, a preliminary determination assigned
the specimen to the Ropalidia formosa complex. Presently
there are several species masquerading under the name R.
formosa, and the specimen probably corresponds to a spe-
cies currently treated as a synonym, but an examination of
type specimens is necessary for final conclusions.