Impact of Repeated Applications of Alpha- Cypermethrin on Eldana Saccharina (lepidoptera:pyralidae) and on Arthropods Associated with Sugarcane

In five field–scale insecticide trials, the repeated application of the synthetic pyrethroid alphacypermethrin to carry-over cane, reduced damage caused by the sugarcane borer Eldana saccharina Walker (Lepidoptera: Pyralidae) to the crop. The insecticide was applied with mistblowers at a rate of 200 ml formulation/ha in 350 L water/ha, once every two weeks for 16 weeks, commencing when the crop was 6-9 months old. At harvest, average damage and larval numbers were reduced by 72% and 73% respectively. ERC % cane increased by an average of 28%. Arthropods were monitored in two of the trials by means of pitfall trapping. Results showed that there was some impact of the treatment on abundance and diversity, primarily over the period of treatment application. However, at crop harvest, five months after treatment application ended, there was no significant effect. The impact on ants, considered important predators of eldana, was similar. It is concluded that this approach to suppressing borer infestations may have commercial value.