【Abstract】 Objective To explore the value of isozyme zymograms in the classification of blackflies and accumulate basic biochemical data for the study of phylogenesis. Methods EST isozymes of three blackfly species were studied by discontinuous PAGE techniques. Results Ten isozyme bands could be identified according to the electrophoresis zymograms. The differences of zymograms were significant between three blackfly species and each species had its own special zymogram. The main band among intraspecific individuals or between the larvae and pupae was alike， however， other enzyme bands were different. Conclusion EST isozyme zymograms could be used as one of the classification characteristics of blackflies.

Objective To evaluation the efficiency of Diphacinon Na against R.flavipectus in area of Diphacinon Na applied for a long time.Methods A saturated Diphacinon Na bait was applied at different baits for a 7 day period in field test.Results Paddy with this rodenticide at 0.10% and 0.16% the feeding rates of R.flavipectus were 35.99% and 26.21%,the killing rates were 79.44% and 92.70%.The feeding rate and killing rate for R.flavipectus were 38.36% and 85.92% at 0.10% wheat bait treat ment.The feeding rate showed significant difference(χ ²= 12.97, P< 0.01)and the killing rate showed no statistical significance(χ ²=0.32, P>0.05) between 0.10% and 0.16% paddy bait.The feeding rate and killing rate showed no significant difference(χ ²= 0.64, P>0.05,χ ²= 0.03, P>0.05) between 0.10% paddy bait and 0.10% wheat bait.Conclusion The killing effect still was well and blindly raise the concentration of bait was not suitable for Diphacinon Na against R.flavipectus.But for switched rodenticides application should be paid more attention.