CYTOLOGICAL STUDY OF THE ASIAN PAPAYA FRUIT FLY
The Asian papaya fruit fly, Bactrocera papaya Drew & Hancock is a key pest among the tephritid (Diptera: Tephritidae) groups of Asia and the Pacific. It has been recorded from 193 host plant species in 114 genera and 50 families in Asia. The larval stages feed on edible fruits and fleshy vegetables and cause serious financial damage. Females lay eggs in green papaya, citrus, carambola, sweet gourd, cashew, pummelo, mango, guava, bananas and many more commercially grown fruits and vegetables in Southeast Asia. Because of their widespread horticultural impact and rapid range expansions, tephritid fruit flies are the subject of quarantine and control efforts worldwide. The efforts for controlling of this pest are based mainly on chemical insecticides. However, there is potential for application of genetic control techniques, such as sterile insect technique (SIT), sterile male technique (SMT) and other autocidal methods. Cytogenetic information is a fundamental beginning for understanding the biology of insect pests, as well as for developing new genetic control strategies. The present study constitutes the first attempt to describe the mitotic metaphase chromosomes of B. papaya. The detailed karyotype information (the number, centromeric index, relative length, arm ratio, chromosome morphology) are presented. The species had six pairs of chromosomes. The male was heterogametic (XY) and the female was homogametic (XX). The chromosome number was 12 (10 autosomes + XX or XY). There were 2 pairs of submetacentric, 1 pair metacentric and 2 pairs of acrocentric chromosomes. The X chromosome was submetacentric and long while the Y was a dot-like chromosome and totally heterochromatic. One arm of the X chromosome was also heterochromatic. This work showed that B. papaya is suitable for further cytogenetic studies in this species and may be used as reference for other Bactrocera spp., most of which are also serious horticultural pests.
Yesmin , F. and Clyde, M.M. (2014). CYTOLOGICAL STUDY OF THE ASIAN PAPAYA FRUIT FLY. Acta Hortic. 1024, 301-305
karyotype, mitotic chromosome measurements, genetic control, tephritidae, polyphagous pest