Narit Thaochan, Richard A.I. Drew, Anuchit Chinajariyawong, Anurag Sunpapao, and Chaninun Pornsuriya

pp. 617 - 624

Abstract

The community structure of the alimentary tract bacteria of two Australian fruit fly species, Bactrocera cacuminata
(Hering) and Bactrocera tryoni (Froggatt), was studied using a molecular cloning method based on the 16S rRNA gene.
Differences in the bacterial community structure were shown between the crops and midguts of the two species and sexes of
each species. Proteobacteria was the dominant bacterial phylum in the flies, especially bacteria in the order Gammaproteobacteria which was prominent in all clones. The total bacterial community consisted of Proteobacteria (more than 75% of
clones), except in the crop of B. cacuminata where more than 50% of clones belonged to Firmicutes. Firmicutes gave the
number of the secondary community structure in the fly’s gut. Four orders, Alpha-, Beta-, Delta- and Gammaproteobacteria
and the phyla Firmicutes and Actinobacteria were found in both fruit fly species, while the order Epsilonproteobacteria and
the phylum Bacteroidetes were found only in B. tryoni. Two phyla, Actinobacteria and Bacteroidetes, were rare and less
frequent in the flies. There was a greater diversity of bacteria in the crop of the two fruit fly species than in the midgut. The
midgut of B. tryoni females and the midgut of B. cacuminata males had the lowest bacterial diversity.