Lethal and sublethal effects of four insecticides on egg and first larvae green lacewing Chrysoperla carnea in laboratory conditions

The common green lacewing is one of the important predators in the field and greenhouse. In this study, lethal effects of azadirachtin, flonicamid, thiacloprid and thiocyclam againstegg and first instar of Chrysoperla carnea were studied in the laboratory. Larval bioassay was carried out with contact method in glass Petri dishes, while egg bioassay was conducted with immersion method. Mortality of eggs and larvae were measured after 72 h and 96 h, respectively. In order to study the sub-lethal effects of the treatments, first instars were subjected to LC25 of each treatment, and the effects were estimated based on IOBC method. Experiments were conducted at 25 ± 2 ºC, 65 ± 5% relative humidity and a photoperiod of 16: 8 h (L:D). The estimated LC50 of azadirachtin, flonicamid, thiacloprid and thiocyclam for eggs were 510, 451, 394, 862 ppm, while for the first instar, it was 596, 37, 124 271 ppm, respectively. The mean fertility rate for control, azadirachtin, flonicamid, thiacloprid and thiocyclam were 291.32±13.7, 279.67±11.86, 235.75±12.84, 177.84 ± 13.87 and 99.85 ± 10.58 eggs, respectively. Based on IOBC classification method, azadirachtin and flonicamid were categorized as 'not harmful', while thiacloprid and thiocyclam were categorized as 'slightly harmful' against C. carnea. If our results are corroborated with field tests, flonicamid and azadirachtin can be incorporated in integrated pest managements of the field where this predator is active.