The species composition and bioregulatory activity of entomophages in potato pest control system

Entomophages are considered one of the most important crop pest regulators. Thus, predatory bugs of the subfamily Asopinae - Perillus bioculatus Fabr., Podisus maculiventris Say, Oplomus nigripennis var. pulcher Dull. and parasitic flies Doroforofaga have been introduced to control the Colorado potato beetle ( Leptinotarsa decemlineata Say), a super-dominant species, damaging the ground part of potato in several European countries. In this paper, the species composition of the insect fauna of potato cenosis has been studied in Crimea, Slavinsky, Krasnoarmeysky, Dinskoy and Seversky regions of Krasnodar Krai in 2009-2014, as well as population dynamics of injurious and beneficial species populations depending on the abiotic and biotic factors. A total of 35 species belonging to 16 families of 7 insect orders were detected during the study period. Six aphid species ( Homoptera, Aphididae ) were identified: buckthorn aphid ( Aphis nasturtii Kalt.), potato aphid ( Aulacorthum solani Kalt.), peach aphid ( Myzodes persicae Sulz.), beet or bean aphid ( Aphis fabae Scop.), geum aphid ( Macrosiphum euphorbiae Thom.), and melon or cotton aphid ( Aphis gossypii Glov.). Of six lady bugs species, the Coccinella septempunctata L., Propylea quatuordecimpunctata L. and Harmonia axyridis Pallas were the most frequent. The predatory bugs of Pentatomidae family were the most abundant in the Hemiptera order. The acclimatization of predatory stinkbug populations Perillus bioculatus F. in the South Russia has been determined, that is of major interest for the biological control of the Colorado potato beetle. The synchronous emergency of overwintered stages of Colorado potato beetle, Perillus bioculatus, Zicrona caerulea and other Asopinae predatory bugs was registered. However, small natural population of P. bioculatus Fabr. could not always overcome the pest at the beginning of the vegetation, therefore P. bioculatus laboratory population was used together with Podisus maculiventris Say population which further control the Colorado potato beetle during the growing season. P. maculiventris developed on potato and did not leave solanaceous crops at imago stage continuing to eat Colorado potato beetle and to lay eggs. Due to the optimal feed (eggs of Colorado potato beetle) Perillus number increased to 0.6 insects per bush, and the number of Colorado potato beetle eggs was reduced to 0. Also, the sensitivity of the entomophages to chemicals and biologicals was studied. Incompatibility of Perillus and Podisus with chemical insecticides was detected, while biological agents Bitoksibatsillin and Fitoverm did not affect the predatory bugs. Thus, since 2008, when P. bioculatus bug acclimatization in Krasnodar region was found, the bug has managed to adapt well to the new environment due to use new feed, and high predatory and migration ability. The study of predatory bug Perillus contributes to L. desemlineata control in South Russia.