Sterilization of banana fruit infested with banana fruit fly

Abstract

Bananas grown in northern Queensland are picked while hard and green and ripened and marketed in the southern States of Australia, where fruit infested by Dacus (Strumeta) spp. is unacceptable. Of the two species of Dacus known to attack banana in northern Queensland, D. (S.) tryoni (Frogg.) does not infest hard, green fruit, but D. (S.) musae (Tryon) [cf. RAE A 52 437], which is normally associated with wild banana (Musa banksii) in rain forests, may attack unripe cultivated fruit if nearby bunches have been mechanically injured. Less than 1% of the harvested fruit is usually affected and this is discarded during packing, but since some may be overlooked, an attempt was made to develop a chemical treatment that would destroy the larvae in the fruit. B. M. Braithwaite found that liquids containing 0.05% fenthion or 0.03% dimethoate killed D. tryoni in bananas dipped in them and did not adversely affect the fruit or leave residues likely to be unacceptable, and these materials, with phosphamidon, were accordingly tested against D. musae. No adults emerged from fruit dipped in solutions of 0.01 % fenthion or 0.03 % dimethoate for five seconds, but there was some emergence in one of two treatments after dipping in 0.01 % dimethoate for three minutes. Phosphamidon exerted little control.