The life cycle of Cacopsylla bidens was studied in the souther region of Syria (Sweida) during 1999-2000. This insect was first identified in Syria as asole-host species, which enters the winter dormancy as an adult out of the pear orchards in both the sites. The insect enters the pear orchard at the end of the winter, and the summer adult insects emerge after the fall of flowers petals, and continue the whole. Summer up to mid of autumn, and the winter form emerges during the first 10 days of August. The harsh environmental conditions and the biological enemies (predators) push the insect to migrate out of the pear orchards during autumn. A survey and identification of the insect natural enemies was carried out during the whole study period, they were Anthocoris nemoralis, Orius horvanthi, Campylomma spp., Deraecoris spp., and Psallus spp., which registered on C. bidens at few locations, in Alkafer district on the trees of Pyrus Syriaca during summer. The encyrtidae parasoitoid Trechnites psyllae was registered for the first time in Syria on the nymphs of C. bidens as a dominant parasite. The highest percentage of parasite (66%) was found at Saragaia Researchs Station during the autumn generations. And also the parasite Ennotus spp. was noticed, but with low density at the end of the season.