Abstract
In this paper, the toxicity of DDT and BHC dust to the aphids and their natural enemy, the lady beetle (Harmonic axyridis PALLAS) of pear orchards has been compared in the laboratory. The results are summarized as follows:
1. BHC is more toxic than DDT to the aphids, Toxoptera piricola MATSU, and Nippolachnus piri MATSU.
2. BHC is less toxic than DDT to the various stages of the lady beetle, Harmonia axyridis PALLAS
3. From the above mentioned results it may be said that BHC is recommended for the control of these aphids.
