Identification of larval salivary gland polytene chromosomes of the peach fruit fly, Bactrocera zonata (Saunders) (Diptera: Tephritidae)

Abstract

Peach fruit fly, Bactrocera zonata (Saunders) (Diptera: Tephritidae) is native to South and South-East Asia. It is a polyphagous species and has a high reproductive potential (approx. 600 eggs in a lifetime), high biotic potential, i.e., several generations of progeny per year. The species has the rapid dispersal ability and can be active throughout the year. Its establishment may have a serious impact on the environment following the initiation of chemical and/or biological control programmes. B. zonata is of quarantine significance to EPPO (European and Mediterranean Plant Protection Organization) countries and it is classified on the A1 list of pests recommended for regulation as quarantine pests by Centre for Agriculture and Biosciences International (CABI). The present study initiates an attempt to identify the larval (3rd instar) salivary gland polytene chromosome arms of B. zonata using Olympus phase contrast microscope CX 41. A photographic representation of the polytene chromosomes of this species associates with identifying tips as well as well defined characteristics of each polytene chromosome arms are described. Five long chromosomes with their identifying tips are recognized in each polytene nucleus. Polytene chromosomes are of special interest to construct a Genetic Sexing Strain (GSS) of a pest species and it can play an important role for the successful application of Sterile Insect Technique (SIT) in field application as part of the biological control programme under Integrated Pest Management (IPM) scheme.