Population density of the tortoise beetle, cassida vittata, vill. (coleoptera: chrysomelidae) and the role predators on sugar beet at el-beheira governorate

The study carried out at three districts of El Mahmoudia, Damanhur and Rashid, El Beheira Governorate, Egypt during the two successive seasons 2011/12 and 2012/2013 . Under filed climate, C. vittata was appeared in sugar beet as adults with a few numbers in the last week of December, while eggs were appeared week later. the tortoise beetle C. vettata in all stages observed high numbers in the second season 2012/13 comparative with season 2011/12. On the other hand, only five species of insect predators were recorded on the sugar beet crop during the survey period. The dominant one of the predators was C. undecimpunctata adults which observed with high number and for long time. Temperature was effected negatively significant on C. vettata in the first season more than in the second while related humidity not observed any effect in the pest population during the two successive seasons.