Population dynamics and predation on two pest species by Hippodamia variegata (Goeze) in Korla fragrant pear orchards of Xinjiang, China

• The population dynamics of Hippodamia variegata in Korla fragrant pear orchards tracked Aphis spiraecola more closely than Cacopsylla chinensis . • A. spiraecola remains were detected more often in the gut of H. variegata than those of C. chinensis . • In laboratory trials, both male and female H. variegat a consumed more A. spiraecola than C. chinensis . Development of biological control techniques tailored for the pests of local cropping systems is a key activity supporting regional agricultural production. Predatory natural enemies, such as ladybeetle species, are often important forces restraining pests in agroecosystems. One such ladybeetle is Hippodamia variegata (Goeze), which is an important predator in the cultivation of Korla fragrant pear in Xinjiang Uygur Autonomous Region of China. We analyzed the seasonal dynamics and pest control efficacy of H. variegata , using a mixture of population ecology and molecular biology techniques. We found that H. variegata exhibited a stronger temporal response to Aphis spiraecola Patch. Also, the use of molecular markers for prey DNA in the guts of this ladybeetle showed a higher rate of detection of A. spiraecola than of the psyllid Cacopsylla chinensis (Yang & Li). Both male and female adult ladybeetles demonstrated a greater predation rate on A. spiraecola than on C. chinensis . The results suggest that H. variegata is potentially an important biological control agent against A. spiraecola in pear orchards.