Pb. Morais et al., YEAST COMMUNITIES OF THE CACTUS PILOSOCEREUS-ARRABIDAE AS RESOURCES FOR LARVAL AND ADULT STAGES OF DROSOPHILA-SERIDO, Antonie van Leeuwenhoek, 66(4), 1994, pp. 313-317
The feeding behavior of Drosophila serido on the yeast communities of
necrotic stem tissue of Pilosocereus arrabidae were studied in a sand
dune ecosystem of Rio de Janeiro, Brazil. The prevalence of cactophili
c yeasts including Pichia barkeri, Candida sonorensis and Geotrichum s
p. in the crops and external surfaces of D. serido reflected its assoc
iation with the cactus habitat. The effective number of yeasts vectore
d on the surface of flies was higher than that in the crops. Also over
lap between the yeasts from stems and from crops was partial suggestin
g selective feeding by the flies in the substrates visited. The female
s had a higher effective number of yeast species and a lower similarit
y than males with the yeast community of P. arrabidae. This was probab
ly related to the search for oviposition sites by females. The presenc
e of Pichia thermotolerans-like and Pichia amethionina var pachycerean
a in the flies, but not in P. arrabidae stems, indicated that D. serid
o was not limited to this cactus species. The larvae and adults lived
in different patches with the adults feeding in patches with higher ye
ast species richness. The larvae had a narrower feeding niche and high
er overlap with Fl arrabidae, and preferred P. barkeri and Pichia cact
ophila as food. Adult flies fed on patches with the most frequent yeas
ts except for P. cactophila. Pichia caribaea was found in higher frequ
ency in the adult crops than in the stems. Our data suggested that the
re was food selection and diet partitioning between adult and larval s
tages of D. serido.