Natural enemies of Colorado potato beetle, Leptinotarsa decemlineata (Say) and population fluctuation of green lacewing, Chrysoperla carnea Stephen in potato fields of Ardabil plain, Iran

Colorado potato beetle, Leptinotarsa decemlineata is one of the most important pest insects in main potato growing areas. Natural enemies of the Colorado potato beetle was collected and determined in potato fields of Ardabil province, Iran. Based on the results, the predatory species of Chrysoperla carnea, Coccinella septempunctata, Hippodamia variegate and
Nabis punctatus from the class Hexapoda, and Enoplognatha mediterranea from the class Arachnida were determined as natural enemies of the Colorado potato beetle in Ardabil. In addition to predatory arthropods, an entomopathogenic nematode, Hexamermis sp., and an isolate of Bacillus thuringiensis were collected and determined as the most important biological control agents of the pest population. Among identified arthropods, population of lacewing C. carnea was considerable in potato fields. Therefore, its population fluctuation was studied in Ardabil plain. Obtained results showed that C. carnea produced only one generation during the activity period of the Colorado potato beetle in Ardebil potato fields. Moreover, the entomopathogenic nematode, Hexamermis sp. was the most important natural enemy of the Colorado potato beetle so that it could destroy up to 80 percent of overwintering population of the pest in potato fields before spring.