MITOTIC AND POLYTENE CHROMOSOME ANALYSES IN THE QUEENSLAND FRUIT-FLY,BACTROCERA-TRYONI (DIPTERA, TEPHRITIDAE)

The Queensland fruit fly, Bactrocera tryoni, like the Mediterranean fr uit fly, Ceratitis capitata, has a diploid complement of 12 chromosome s, including five pairs of autosomes and a XX/XY sex chromosome pair. Characteristic features of each chromosome are described. Chromosomal homology between B, tryoni and C, capitata has been determined by comp aring chromosome banding pattern and in situ hybridisation of cloned g enes to polytene chromosomes. Although the evidence indicates that a n umber of chromosomal inversions have occurred since the separation of the two species, synteny of the chromosomes appears to have been maint ained.