In the last years, the fruit fly Zapronius indianus became the most important plague of Brazilian fig production. A fermentation process is associated with infection of the fruit by this fly. A single yeast species, Candida tropicalis, was identified in all the infected figs. The presence of one species and the low genetic variability (RAPD) of the isolates indicates an uncommonly strict interaction between C. tropicalis and Z. indianus.
Key words: Zaprionus indianus, Candida tropicalis, RAPD markers, yeast-insect associationThe first register of the occurrence of Zaprionus indianus in the American continent was made in Japanese pergammon fruits in São Paulo State, Brazil. In the same region and agricultural season, these flies were observed feeding and laying eggs at the ostiole region of fig fruits in the beginning of the maturation period (14). This fly of African origin, recently introduced in Brazil, is not considered a plague in Africa. However, the loss estimates in fig production in Brazil since its appearance is around 50%, becoming the most important plague of this fruit in less than two years from the first report.The genus Zaprionus is formed by two sub-genera and 56 species (3). Z. indianus is the only species observed in tropical regions like the Comores Islands, Madagascar, Reunion Islands, Canary Islands, India, Sauddith Arabia (2), and now in Brazil. Z. indianus is a fly of about 2.5 to 3.0 mm length, with light brown body, red eyes, and characteristic longitudinal black and white stripes along the dorsal region of the head and thorax.Most of the species of the Drosophilidae family are associated to yeast and bacteria communities. Metschnikowia hawaiiensis (6), Candida amapae, Kloeckera sp., Hanseniaspora sp., Candida guillermondii, and C. krusei The study of the microbial communities associated to the drosophilid Zaprionus indianus is especially important considering the plague status of this fruit fly in Brazil. In the present paper, we identified the yeast species associated with Zaprionus indianus in the subtropical region of São Paulo State, Brazil.Four infested and four non infested figs were collected at four different farms at the Valinhos region, São Paulo State, Brazil, giving a total of sixteen infested and sixteen non infested fruits. The figs were opened and samples from the inner part of the fruits were plated on appropriate media.Yeasts were isolated on YEPD (1% yeast extract, 1% peptone, 2% glucose, and 2% agar) medium with 100 mg/l of ampicilin, 25 mg/l of tetracycline and 100 mg/l of kanamycin. Bacteria were isolated on YEPD medium with 100 mg/l of nystatin. Ten yeast and bacterial colonies from each sample were isolated and purified on the above media.