The pine sawyer beetle, Monochamus galloprovincialis, is a pest of pine trees in Europe and North Africa. Previously considered a secondary pest of stressed and dying trees, it is now receiving considerable attention as a vector of the pine wood nematode, Bursaphelenchus xylophilus, the causal agent of a lethal wilting disease in susceptible species of pines. Adult beetles are attracted to traps baited with a kairomone blend consisting of a host volatile, alpha-pinene, and two bark beetle pheromone components, ipsenol and 2-methyl-3-buten-2-ol. More recently it has been shown that mature male M. galloprovincialis produce a pheromone that attracts mature females in a laboratory bioassay. Here, volatiles were collected from mature male and female M. galloprovincialis, and a compound produced specifically by mature males was identified as 2-undecyloxy-1-ethanol from its gas chromatographic retention times, its mass spectrum, and by comparison with synthetic standards. The naturally-derived and synthetic compounds elicited electroantennographic responses from both females and males. Sealed polyethylene vials and polyethylene sachets were shown to be effective dispensers with zero-order release, the latter giving a higher release rate than the former. In two field tests, multiple-funnel traps baited with synthetic 2-undecyloxy-1-ethanol caught both female and male M. galloprovincialis, with higher catches at the higher release rate. This compound also synergized the attractiveness of the kairomone blend, the combined mixture catching 80-140% more beetles than the sum of the catches to each bait separately and luring up to two beetles/trap/d in a moderate-density population. We conclude that 2-undecyloxy-1-ethanol is a male-produced aggregation pheromone of M. galloprovincialis. This is the first example of a sex-specific compound in the cerambycid subfamily Lamiinae with significant behavioral activity in the field at a range sufficient to make it a useful trap bait. The possible roles of this pheromone in the chemical ecology of M. galloprovincialis and its potential use in pine wilt disease management are discussed.

The pine sawyer Monochamus galloprovincialis is the European vector of the recently introduced pine wood nematode. This nematode is the causal organism of pine wilt disease, a serious tree killer in East Asia. Efficacious baits and traps to monitor and control this beetle are now required. The effect of bark beetle (Ips spp.) pheromone components, released individually (ipsenol) or in blends (ipsenol, ipsdienol, cis-verbenol and methyl-butenol), together with host volatiles (turpentine or a-pinene and ethanol) on M. galloprovincialis trap catches has been studied in Spain. A kairomonal response by male and female of M. galloprovincialis to Ips semiochemicals was found. Beetles were more attracted to host blends supplemented with bark beetle pheromones than to host volatiles alone. Ipsenol alone was attractive to pine sawyers, and was synergistic with a-pinene and ethanol. The full blend of the four Ips semiochemicals and the host compounds was highly attractive. Multiple-funnel traps were as effective as black cross-vane traps in capturing this insect when the escape of trapped beetles was prevented. Trapping of non-target bark beetle predators was also evaluated. The trogossitid Temnochila coerulea and clerid Thanasimus formicarius were kairomonally attracted to and killed in traps baited with bark beetle pheromones. These results suggest that effective monitoring of M. galloprovincialis would be possible by baiting any of these traps with host volatiles and Ips semiochemicals, but reduction of the lure components and trap modification to minimize impact on predators should be considered.

Monochamus galloprovincialis Olivier (Col., Cerambycidae) is a vector of the pine wood nematode, Bursaphelenchus xylophilus, causing the destructive pine wilt disease. An effective lure for monitoring and/or masstrapping would be of great interest in the management of this pine sawyer. Males and females of this species show an attractive kairomonal response to blends composed of four pheromone compounds used by Ips spp. bark beetles and two host volatiles from pines. This six-component lure is highly attractive but may to be too complex and costly for practical use as each component is released from a separate lure. The role of each component, ipsdienol, ipsenol, cisverbenol, methyl butenol, a-pinene and ethanol as attractants for M. galloprovincialis was field tested in Spain to obtain a simpler but equally effective bait. Ipsenol was confirmed as the strongest kairomonal signal to M. galloprovincialis synergizing response to a-pinene by 95 times. The addition of methyl butenol to this blend doubled the number of males and females trapped. On the other hand, neither ipsdienol, cis-verbenol nor ethanol improved the results when incorporated into the above three-component blend. A lure consisting of ipsenol, methyl butenol and a-pinene may be very cost-efficient in operational monitoring or mass trapping of M. galloprovincialis. Three potentially repellent candidates, ())verbenone, methyl cyclohexenone and trans-conophthorin, were also tested against the attractive threecomponent bait. trans-Conophthorin significantly reduced male catches of M. galloprovincialis; methyl cyclohexenone had no effect. Verbenone significantly enhanced the response of females to the attractive combination of a-pinene, ipsenol and methyl butenol.

No abstract

Monochamus galloprovincialis Olivier (Coleoptera: Cerambycidae) is the European vector of the pine wilt nematode, Bursaphelenchus xylophilus (Steiner and Buhrer) Nickle, which causes the pine wilt disease. A series of experiments were carried out to determine the existence of a contact pheromone on the female's cuticle. All males tested tried to copulate with freshly killed females, but none tried to copulate with the same females after they had been washed with hexane. When the hexane extract was reapplied to the extracted females, 50% of the males tried to copulate with them. This shows that females have a contact pheromone on their cuticle that stimulates male copulatory behavior. Cuticular compounds (mainly hydrocarbons) were sampled with solid phase microextraction and solvent extraction. No marked differences between sampling methods were observed. Individual peak analysis revealed that 23 compounds were significantly more abundant in females and eight were more abundant in males. Correspondence analysis found significant differences between the global hydrocarbon profile of male and female M. galloprovincialis. Individually, these compounds represented a small percentage of the total blend. This suggest that males of M. galloprovincialis may distinguish females by a blend of several, not very abundant, compounds that are present in both sexes but in different proportions.

No abstract

No abstract