Abstract:
Species, amounts and population dynamic of hyperparasitoids of
Myzus persicae (Sulzer) were investigated systematically in tobacco fields and breeding greenhouse. The results showed that there were three hyperparasitoids of
Myzus persicae, including
Pachyneuron aphidis (Bouche),
Asaphes suspensus (Nees), and
Dendrocerus carpenteri Curtis. The occurrence of the hyperparasitoids was 25 days behind those of
Aphidius gifuensis, but the peak occurrence had only 5 day difference, which is one of the major factors restricting the quantity of
Myzus persicae population in tobacco field. At breeding greenhouse all year round the highest hyperparasitic rate was 65.0%, but the emergence rate of
Aphidius gifuensis was less than 1.0%. In field during production cycle the highest hyperparasitic rate did not exceed 10%. At the process of breeding greenhouse, the highest emergence rate of
Aphidius gifuensis was 7 and 21 days after releasing
Aphidius gifuensis, but the hyperparasitic rate was at lowest during 7 and 14 days after releasing
Aphidius gifuensis. So it was suggested that the best time of producing
Aphidius gifuensis was 7 and 14 days after releasing
Aphidius gifuensis in field during a production cycle.