Turkiye Entomoloji Dergisi, vol.39, no.4, pp.345-353, 2015 (SCI-Expanded)
Antifeedant activity and growth inhibition effects of Achillea millefolium L. (Asteraceae), Heracleum platytaenium Boiss (Apiaceae), and Humulus lupulus L. (Cannabaceae) extracts were tested on the third instar larvae of Colorado potato beetle (Leptinotarsa decemlineata Say, Col: Chyrsomelidae) under laboratory conditions. Plant extracts were obtained treating "cones" of H. lupulus, leaves and stems of H. platytaenium and leaves, stems and flowers of A. millefolium with methanol using maceration technique. The plant extracts (50 g/L) were applied to potato leaflets and consumption area for individual insect was measure with a planimeter after 24, 48 and 72h. The single dose screening bioassay revealed that all tested plant extracts possessed antifeedant activity against the beetle larvae at 50 g/L concentration and average consumed leaf area were 0.04 cm2, 0.05 cm2 and 0.30 cm2 for H. lupulus, H. platytaenium and A. millefolium respectively. In dose response bioassay, it was revealed that there was a negative correlation between the averages consumed leaflet area and the plant extract dose. The greatest antifeedant activity was seen in H. lupulus extract treated leaflets at 10 g/L concentration and the average consumed leaflet area was 0.68 cm2 after 72 h. The H. platytaenium and H. lupulus extracts had similar effects on the larval growth indices. Both plants extracts had 1.2 growth index values at 30 g/L concentration. These results indicate that the H. platytaenium and H. lupulus extracts could have significant potential as antifeedant and larval growth inhibition agent in the control of larvae of Colorado potato beetle.