Chemical control of the sorghum shoot fly Atherigona varia var. soccata Rondani (Diptera: Anthomyiidae) in south India

In India, the sorghum hybrids CSH-1 and CSH-2, which were developed in the 1960's, produce a 70% greater grain yield than local cultivars and produce comparable fodder yields. However, acceptance of the hybrids in Karnataka State, has been slowed by their susceptibility to attack by Atherigona soccata Rond. (varia var. soccata). When systemic insecticides were evaluated against the fly in field tests at Bangalore during 1970-71, dead-heart counts and number of eggs/plant 7, 14, 21 and 28 days after germination showed that seed treatment with carbofuran or pre-sowing furrow treatments with granules containing carbofuran disulfoton or phorate gave the most effective control. It was noted that fly attack occurred even in winter in southern Karnataka, and the weight of earheads and fodder appeared to be related to the degree of fly control.ADDITIONAL ABSTRACT:To protect the susceptible new sorghum hybrids CSH1 and CSH2 from sorghum shoot fly, seeds were either treated with carbofuran wettable powder at 4, 5, 6 and 8% a.i. before sowing, or were sown in soil furrows to which carbofuran 3G or 10G, phorate 10G, cytrolane 10G or disulfoton 10G had been applied at 3 rates. After 28 days all treatments except quick-release carbofuran 3G and cytrolane 10G gave effective control. Weights of ears and green fodder appeared to be positively correlated with the degree of shoot fly control. Of the treatments tested, phorate 10G at 16 kg/ac as soil application and 6% carbofuran as seed treatment were recommended; however, seed treatment cost only one-third as much as soil treatment and was equally effective