A preliminary study on the biological characteristicsof Pseudoptygonotus prominemarginis

The biologycal characteristics of Pseudoptygonotus prominemarginis Zheng et Mao were investigated. Each generation of the species found in Dali, Yunnan province lasts for one year. It hibernates mainly as 3rd instar nymph. The egg deposited in the ground begins of hatching in the last 20 days of September. The duration of the life nymph consists of 5 stadiums. It emerges as adult in the first 20 days of May next year. The egg and nymph stages last respectively for 90.5 and 184.5 days in average. The adult stage lasts for 18～23 days. A female can produce 24.9 eggs in average. The adult dies from the last 10 days of June to the first 10 days of August individually. Many natural enemies of this species have been found.