Dose-response relationships for the antifeedant effects of Humulus lupulus extracts against larvae and adults of the Colorado potato beetle.
BACKGROUND
Dose-response relationships for antifeedant effects of H. lupulus extracts against larvae and adults of the Colorado potato beetle (CPB) were determined in laboratory conditions. The larval and adult beetles were fed on potato leaflets treated with H. lupulus extract ranging from 0.4 to 40 mg mL(-1) in a no-choice situation. Their feeding behavior was recorded, and larval growth and antifeedant indexes were calculated.


RESULTS
H. lupulus treatments significantly affected larval growth rate, and at higher concentrations the larval weights were significantly reduced over the course of the assay. Adults of CPB were more sensitive to the extracts than the larvae, and, even at lower doses, adult beetles were arrested for longer periods than larvae.


CONCLUSIONS
These results indicate that H. lupulus extracts may have potential for control of CPB, particularly in organic farms where conventional insecticides are not available.
Department of Plant Protection, Agriculture Faculty, Gaziosmanpasa University, Tokat, Turkey. agokce@gop.edu.tr
Ayhan
A
Gökçe
Rufus
R
Isaacs
Mark E
ME
Whalon
D000818:Animals; D001517:Coleoptera / Q000187:drug effects* / Q000254:growth & development / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D005247:Feeding Behavior / Q000187:drug effects; D027582:Humulus / Q000737:chemistry*; D007814:Larva / Q000187:drug effects* / Q000502:physiology; D010935:Plant Diseases / Q000469:parasitology*; D010936:Plant Extracts / Q000494:pharmacology*; D011198:Solanum tuberosum / Q000469:parasitology*
D010936:Plant Extracts