Laboratory Studying of the Fecundity Schedules for Neochetina bruchi (Hustache) [Coleoptera : Curculionidae] under the Lab . conditions and the Possibilities of its Use Against Waterhyacinth in Iraq .

Abstract

Fecundity schedules results of Neochetina bruchi ( Hustache ) indicated that the highest reproductive rate was 132.2 eggs / female at 25 °C while it was 106.4 and 110.8 eggs / female at 20 and 30 °C successively and expectant reproductive was 29.27,50.23 and41.73 eggs at 20 ,25 and 30 °C successively .while the temperatures 15 and 35°C were appeared to be lethal. Furthermore ,the results also showed that the highest net reproductive rate ( Ro ) was 50.23 female /female / generation at 25 °C while it was 29.27 and 41.73 female /female / generation at 20 and 30 °C, moreover the highest mean generation time ( T ) was 80.84 days at 20 °C while the lowest mean generation time ( T ) was 98.30 days at 25 °C. Results also revealed that the highest rate of intrinsic increase in population ( rm ) was 0.046 female / female /day at 30 °C while it was 0.034 and 0.045 female / female /day at 20 and 25 °C successively