Attraction of red turpentine beetle and otherScolytinae to ethanol, 3‐carene or ethanol + 3‐carene in anOregon pine forest

Abstract

AbstractRed turpentine beetleDendroctonus valensLeConte is a non‐aggressive bark beetle inNorthAmerica that attacks weakened or recently dead pines, as well as their fresh logs or stumps. Fire‐injured ponderosa pines releasing stress‐induced ethanol are often attacked. The oleoresin from these trees frequently contains 3‐carene as a major component mixed with α‐ or β‐pinene. 3‐Carene lures usually attract moreD. valensthan α‐ or β‐pinene lures or 1 : 1 : 1 mixtures, whereas the attraction of ethanol + 3‐carene lures has never been tested.Funnel traps with ethanol, 3‐carene or ethanol + 3‐carene lures, and a no lure blank, were set‐up as a randomized complete block design in a pine forest nearLaPine,Oregon,U.S.A.,from 23April until 11June 2015.Dendroctonus valens,Hylastes nigrinus,Hylurgops reticulatus,Hylurgops porosusandHylastes gracilisexhibited similar responses, with highest numbers captured in traps with ethanol + 3‐carene. The response by the first three species was confirmed as synergistic.Ipsspp.,Pityogenesspp.,Gnathotrichusspp.,Pachysquamus subcostulatusandHylastes macercomposed a second group whose numbers captured with ethanol lures were similar or greater than the 3‐carene or ethanol + 3‐carene lures. A reducedH. macerresponse to ethanol + 3‐carene was confirmed as an interruption.