Esterase Isozyme of Diamondback Moth

Electrophoresis is currently the best technique for quantifying inherited variation which has contributed to our knowledge of population biology in revealing population structure. Considerable variation in isozymes of diamondback moth, Plutella xylostella (L.), was detected. Esterase zymograms were prepared from 3rd and 4th instar larvae, pupae and adults. There were two groups of esterase bands, which appeared to be independent. The faster band was simple to analyze genetically and involved at least six alleles. In a preliminary study, esterase zymograms of four populations, collected in Shimane and Osaka prefectures of Japan, were compared using these alleles. Gene frequency was different between the four populations, suggesting that esterase isozymes could be useful in analyzing the population biology of diamondback moth.