The identification and description of the chemical signals involved in the aggregation of bark beetles may lead to the development of integrated pest management strategies using synthetic pheromones. Ips sexdentatus Boern. (Col.: Scolytinae) colonizes trees of the Pinus genus across Europe, causing severe damage in occasions. The effect of cis‐verbenol, ipsenol, 2‐methyl‐3‐buten‐2‐ol (MB) and myrtenol in relation to the major pheromonal compound ipsdienol on the aggregation behaviour of I. sexdentatus was studied on four field bioassays. The ternary blend of racemic ipsdienol, cis‐verbenol and racemic ipsenol consistently caught the highest number of bark beetles, resulting in large standardized mean differences (dunbiased > 0.8). The binary blends between ipsdienol and ipsenol, and ipsdienol and cis‐verbenol also improved the performance of ipsdienol, although only ipsenol did it significantly. On the other hand, catches were reduced (dunbiased = −0.96) when MB was released along ipsdienol, although the effect was found to be non‐significant. On a third bioassay, the relative release rates between ipsdienol, ipsenol and cis‐verbenol were studied. Although no differences were found between the ternary blends, a ratio of 1 : 0.25 : 0.5 for ipsdienol, ipsenol and cis‐verbenol, respectively, scored the strongest effect size (dunbiased = 1.17). A fourth bioassay studied the behavioural effects of myrtenol and found no significant modifications to previously established findings. Myrtenol on its own attracted almost no individuals of I. sexdentatus. High numbers of bark beetle predators Thanasimus formicarius L. and Temnochila caerulea Olivier were trapped during the trials. The binary blend between ipsdienol and ipsdienol was shown to catch the highest significant amount of T. formicarius, whereas numbers of T. caerulea caught were highest on the binary blend between cis‐verbenol and ipsdienol. Presented results establish the ternary blend between ipsdienol, ipsenol and cis‐verbenol as a reference functional aggregative lure ready to be used on the management of I. sexdentatus.

The pine sawyer beetle Monochamus galloprovincialis, a secondary pest of pines in Europe and North Africa, has become important as it was identified as the vector in Europe of Bursaphelenchus xylophilus, the causal agent of pine wilt disease (PWD). An effective trapping system is needed, not only for monitoring the insect vector but also for direct control of its population. Trapping may also provide key information on the nematode load carried by the beetles, allowing early detection of infections, provided that captured beetles remain alive within the trap. Highly effective attractants have been developed in recent years that are commonly used in combination with diverse standard trap designs. In this study, several trap designs were developed and compared to commercial standard models in order to determine which designs maximized the number of attracted insects actually caught and the proportion of them remaining alive. In total, 12 trap designs were evaluated in five field experiments carried out in France, Spain and Portugal. Teflon coating applied to the whole trap and extended, ventilated collecting cups resulted in a significant improvement of trap performance. These modifications led to significant increases of pine sawyer catches, up to 275%, when applied to multiple‐funnel or black cross‐vane traps, compared to standard designs. Furthermore, a significant proportion of the captured beetles remained alive within the trap. These findings have been used to develop new commercial traps (Econex Multifunnel‐12® and Crosstrap®; Econex, Murcia, Spain) available to forest managers. A model for insect survival within the trap was also fitted. Elapsed time between consecutive samplings, mean relative humidity and maximum radiation were the three most significant variables. Thus, traps should provide a suitable sample of live insects if sun exposure of the trap is minimized and a reasonable sampling schedule is implemented.

1 Thanasimus formicarius and Temnochila caerulea, two of the main predators of Ips sexdentatus, a well-known forest pest in Southern Europe, are captured in high numbers when trapping I. sexdentatus as a result of the kairomonal effect of the lures used. 2 A preliminary field trial showed that predators could survive for at least 1 week within trapping containers, although predator mutilation and high predator death rates were observed. 3 Different modifications of conventional multiple funnel and slot traps with the objective of reducing natural enemy entrance into trap containers were bioassayed in field experiments conducted over four seasons. Based on the larger sizes of predators, different designs using welded wire-mesh screens improved performance to different extents. Providing escape windows just above the screen on multiple funnel traps gave the most promising results, including when effect sizes among all tested designs were compared. 4 Thus, a simple modification of the lowest funnel of the multiple funnel traps would reduce the bycatch of T. formicarius and T. caerulea, hence improving the efficiency of trapping programmes by lowering the likely impact on natural populations of these predators.

Verbenone and trans‐conophthorin were tested against the aggregation pheromone of the six‐toothed bark beetle (Ips sexdentatus Boern.) on two trapping bioassays. Two different release rates of verbenone (2 mg/24 h and 40 mg/24 h) gave similar significant catch reductions (by 73% and 82%, respectively), whereas trans‐conophthorin lowered the catch by 45%. Joint release of both compounds reduced trap catches by 90%. Furthermore, the effect of these semiochemicals on Thanasimus formicarius L. and Temnoscheila coerulea Olivier, two important natural enemies of I. sexdentatus, as well as Hylurgus ligniperda Fabricius, a native associated scolytid, was evaluated. Both predators were significantly affected by verbenone, whereas the effect on H. ligniperda could not be concluded. Based on these results, verbenone was used in a third experiment to protect standing healthy Pinus nigra salzmannii J. F. Arnold trees from induced I. sexdentatus attack. The experiment consisted of two treatments and 20 paired‐tree replicates. Treatments were pheromone‐baited control trees and baited trees treated with verbenone (60 mg/24 h). These trees served as centres of 10 m radius plots from where a number of plot variables was recorded for local stand description. After the experimental period, all control trees had suffered attacks by I. sexdentatus, whereas trees treated with verbenone were significantly less attacked. Among other stand variables considered in the study, the following characterized the variation among plots most efficiently: (i) plot density, (ii) dominant height and (iii) the proportion of suppressed or (iv) intermediate dominance level trees in the plot. However, these variables did not significantly affect the repellent effect by verbenone. Further research should evaluate the use of verbenone on management strategies of ongoing attacks of I. sexdentatus.