Ar. Kraaijeveld et Nn. Vanderwel, GEOGRAPHIC-VARIATION N REPRODUCTIVE SUCCESS OF THE PARASITOID ASOBARA-TABIDA IN LARVAE OF SEVERAL DROSOPHILA SPECIES, Ecological entomology, 19(3), 1994, pp. 221-229
1. Asobara tabida is a parasitoid of Drosophila larvae in fermenting s
ubstrates. Because it is a widespread species, it may encounter differ
ent biotic and abiotic circumstances in various parts of its range. 2.
The species composition of the host population varies over the parasi
toid's range: D. obscura-group species (especially D. subobscura) are
the main hosts for northwestern and central European parasitoids; D. m
elanogaster is the main host for southern European parasitoids. 3. D.m
elanogaster larvae can defend themselves against A. tabida by encapsul
ating the parasitoid egg, and survival in D. melanogaster is always lo
wer than in D.subobscura. 4. Parasitoids from southern European popula
tions are much better able to survive in D.melanogaster than their nor
thwestern and central European conspecifics; parasitoids from differen
t populations are equally well able to survive in D.subobscura. 5. The
lower survival in D. melanogaster may be partly compensated for by th
e larger size of parasitoids emerging from this host species compared
to parasitoids emerging from D. subobscura. 6. Within population group
s, larger A. tabida females have more eggs in their ovarioles. Additio
nally, southern European females have more eggs and less fat than nort
hern and western/central European females. The relationship between si
ze and longevity is ambiguous. 7. It is concluded that parasitoids fro
m different populations are adapted to region-specific circumstances.