Relative Efficacy of some Insecticides and Neem products for the control of Shoot Flies (Atherigona spp.) in Spring sown Maize

Comparative efficacy of imidacloprid 70 WS at three doses (5, 7.5 and 10g kg⁻¹ seed) as seed treatment, laboratory entrapped phorate in PEG 6000 matric (PEG-Phorate 10) applied @ 0.25 g m⁻¹ row and carbofuran 5G, (slow release) at 0.5 and lg m⁻¹ row commercial formulation of phorate (Thimet 10 G) and carbofuran (Furadan-3G) @ 1 g m⁻¹ row as furrow treatments at the time of sowing and neem kernel dust 10% @ 20 kg ha⁻¹, neem WDP 25%, neem oil 25% EC and Nimbecidine® applied @ 0.1% each as foliar application, were evaluated against shoot fly species (Atherigona soccata Rondani and A. naqvii Steyskal) during spring season. Oviposition, dead-heart formation, chlorophyll content of leaf, leaf area and plant height were studied. The shoot flies did not discriminate amongst the plants receiving different treatments while laying eggs in the field. However, significantly more number of eggs per plant were recorded in 1992 than in 1993. All the Synthetic insecticides including the seed treatment at higher doses significantly reduced dead-heart formation. Phytotonic effect on the plants expressed in terms of more chlorophyll content, larger leaf area, higher plant height vis-a-vis neem formulations and control was observed.