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.

The detection of Bursaphelenchus xylophilus in Pinus pinaster trees in Portugal in 1999 led the official services to implement exceptional and urgent control measures to prevent the spread of the pest. Because the pest is vector‐transmitted, special attention was paid to the insects associated with infested trees. A survey comprising 21 species of insects, from six families, with a total of 1367 specimens, was made in order to evaluate their possible role as vectors of the nematode in Portugal. Five insect species were found to carry other Bursaphelenchus spp., but only Monochamus galloprovincialis was associated with B. xylophilus.

Insects associated with maritime pine, Pinus pinaster, in Portugal were collected and screened for the presence of Bursaphelenchus species.

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1 Pheromone traps are widely used for monitoring or managing insect pest populations. However, it is important to know their range of attraction to optimize the setting of pheromone trap networks. 2 We propose an easy method based on the use of pairs of adjacent traps located at decreasing distance from each other. The range of attraction is deduced from the observation of reduced trap capture when the attraction range of two adjacent traps starts overlapping. The relationship between the relative trap capture and the distance between paired traps is fitted with a logistic curve. 3 To empirically test these predictions, we conducted trapping experiments with the beetle Monochamus galloprovincialis, the insect vector of the pine wood nematode. Fifteen pairs of traps separated by 25 to 300 m, in France, and 18 pairs of traps distant from 25 to 400 m, in Portugal, were installed in maritime pine plantation landscapes. 4 In both countries, the relative percentage of capture per trap per week was best fitted by a logistic model with two parameters. The estimated attraction ranges were 92 m (confidence interval = 62-211 m) in France and 123 m (confidence interval = 64-491 m) in Portugal. 5 The interference between paired traps thus provides a simple and robust method for estimating the attraction range of pheromone traps.

Summary The pinewood nematode (PWN), Bursaphelenchus xylophilus, is the causal agent of pine wilt disease. This species has been reported from the United States of America and Asia associated with important forestry tree species, including pine, spruce, fir, larch and other conifers. However, in Europe, the devastating epidemics centred in Portugal's mainland, and the most recent detections in Madeira Island and in Spain were restricted to Pinus pinaster alone. During the 2013 national survey, wilted Pinus nigra trees, from the central region of Portugal, were sampled. A Bursaphelenchus species was found in very high numbers, with an average up to 5000 nematodes per 10 g of wood, collected from different pine trees. Morphological identification of those specimens, including the presence of a bursa in the male tail, four lateral incisures, shape of spicules, presence of a vulva flap and female rounded tail, was in agreement with the PWN description. Species identification was confirmed also using species‐specific primers targeting the ITS region of the ribosomal DNA to the PWN. Herein, B. xylophilus is reported for the first time associated with declining P. nigra in Portugal, and in Europe. Simultaneously, the insect vector Monochamus galloprovincialis was also detected colonizing the PWN‐infected P. nigra.

& Key message Ambrosia beetles are emerging globally as important agents of tree death and decline. In this work, we observed highly variable attack intensity by ambrosia beetles in cork oak stands in Tunisia. A correlation between the proportion of infested trees and average temperature was found. Tree diameter and tree phytosanitary variables further contribute to the attack densities of ambrosia beetles. Results can be relevant for preventive measures aiming to conserve this natural forest heritage. & Context Cork oak woodlands comprise a unique Mediterranean ecosystem supporting rich biological diversity and providing multiple services. A decline of cork oak forests has been observed in several regions of the Mediterranean Basin in the last four decades, which can be related to climate change, novel biotic agents, and changes in management practices. The ambrosia beetles have been one of the major biotic agents associated with cork oak decline, mostly in the western Mediterranean. & Aims Assess the presence and attack densities of ambrosia beetles in cork oak Tunisian forests. & Methods A total of 15 sites located in North Western of Tunisia, comprising 729 sample trees were evaluated. Using generalized linear models, the presence and density of ambrosia beetles' holes were related to tree and site variables. Variables related to climate, tree (dendrometric parameters, debarking intensity) and biotic agents were examined. & Results The proportion of trees attacked per site varied from 0 to 100%; in four sites, it exceeded 50%. At the site level, the average temperature and tree diameter were the main variables explaining the proportion of attacked trees. Sites with warmer climates showed higher incidence of ambrosia beetles. At the tree level, the presence of attacks increased with tree diameter and concomitantly with intensity of debarking, as well as the presence of tree trunk cavities.

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