Male-biassed response of garden chafer, Phyllopertha horticola L., to leaf alcohol and attraction of both sexes to floral plant volatiles

Summary. Field tests were performed to evaluate theresponse of the garden chafer, Phyllopertha horticola(Coleoptera: Scarabaeidae) to known scarab attractants and toinvestigate the influence of trap colour and height on thenumber of captured beetles. Both sexes were attracted by alure mixture composed of geraniol, eugenol, and 2-phenylethylpropionate (PEP) (ratio 3:7:3). When testing floral volatilesindividually, only geraniol, eugenol and methyl anthranilatebut not PEP was attractive. Response of garden chafer to (Z)-3-hexen-1-ol was strongly male-biassed. Both the responseto floral volatiles and (Z)-3-hexen-1-ol was increased byusing funnel traps with yellow instead of grey vanes. Trapspositioned at 50 and 125 cm above ground captured significantlymore garden chafers than those at 200 cm. Thestrongly male-biassed response to (Z)-3-hexen-1-ol suggeststhat in P. horticola (subfamily Rutelinae) orientation towards plant volatiles emitted upon mechanical damage of plants ispart of the male mate finding strategy as recently demonstratedfor cockchafers of the genus Melolontha (subfamily Melolonthinae). Possible application of plant volatiles forcontrol of P. horticola is discussed.