| 1. |
- Echeveste, Iñaki
(författare)
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Dispersal of Monochamus galloprovincialis (Col.: Cerambycidae) as recorded by mark-release-recapture using pheromone traps
- 2016
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Ingår i: Journal of Applied Entomology. - : Wiley. - 0931-2048 .- 1439-0418. ; 140, s. 485-499
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Tidskriftsartikel (refereegranskat)abstract
- The spread of the pine wood nematode (PWN), Bursaphelenchus xylophylus (Nematoda; Aphelenchoididae), the causal agent of the pine wilt disease, is greatly constrained to the dispersal of its vectors, long-horned beetles of the Monochamus genus. Disease spread at global and regional scales has been mainly caused by human-mediated transport, yet at a local scale, the short- and long-distance dispersal behaviour of the beetles determine colonization dynamics. Three mark-release-recapture experiments using commercial traps and lures allowed the parameterization of the dispersal kernel under two landscape fragmentation scenarios for the only known European PWN vector, Monochamus galloprovincialis. The respective release of 171 and 353 laboratory-reared beetles in continuous pine stands in 2009 and 2010 resulted in 36% and 28% recapture rates, yet, at a fragmented landscape in 2011, only 2% of the released 473 individuals could be recaptured. Recaptures occurred as soon as 7-14days after their release, in agreement with the requirement of sexual maturation to respond to the pheromone-kairomone attractants. Data from the first two experiments were fitted to one mechanical and two empirical dispersal models, from which the distance dispersal kernels could be computed. Derived estimated radii enclosing 50% and 99% of dispersing M.galloprovincialis under continuous pine stands ranged between 250-532m and 2344-3495m depending on the replicate and choice of model. Forecasted recaptures in 2011 resulted in a moderate underestimation of long-distance dispersal, probably influenced by the high degree of habitat fragmentation. In addition, trapping parameters such as the effective sampling area (0.57-0.76ha) or the seasonal sampling range (426-645m) could be derived. Observed results, derived dispersal kernels and trapping parameters provide valuable information for the integrated pest management of PWD. Furthermore, estimated dispersal distances indicate that ongoing clear-cut measures for eradication in the European Union are likely ineffective in stopping the vectors dispersal.
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| 2. |
- Echeveste, Iñaki
(författare)
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Effectiveness of mass trapping in the reduction of Monochamus galloprovincialis Olivier (Col.: Cerambycidae) populations
- 2015
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Ingår i: Journal of Applied Entomology. - : Wiley. - 0931-2048 .- 1439-0418. ; 139, s. 747-758
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Tidskriftsartikel (refereegranskat)abstract
- Monochamus galloprovincialis Olivier beetles vector the causal agent of pine wilt disease (PWD), nematode Bursaphelenchus xylophilus (Steiner and Buhrer) Nickle, in Europe. Traps and attractants have been optimized for the capture of M. galloprovincialis, increasing the possibility of developing methods of lowering its population in PWD-affected areas with the aim of either eradicating the disease or containing the spread of it. To evaluate the effectiveness of such mass-trapping campaigns, two sets of experiments were carried out in 2010 and 2013. The release of 353 laboratory-reared beetles in the experimental area of 2010 facilitated the evaluation of capture-mark-recapture (CMR) procedures in the calculation of population abundance estimates using the POPAN formulation of the Jolly-Seber model, a prerequisite for the assessment of mass trapping. Abundance estimates derived from best-fitting parameters fell within one standard error of the real figures, proving the method appropriate. In 2013, four trap densities were tested in six 36 ha plots. To evaluate the removed proportions, the local beetle population was estimated in a contiguous 260 ha study area. A superpopulation of 21 319 individuals could be calculated from the CMR data, corresponding to a rough density of 82 individuals per hectare. Evaluated trapping densities removed 4.66%, 20.50%, 33.33% and 59.80% of M. galloprovincialis population at 0.02, 0.11, 0.25 and 0.44 traps/ha, respectively, thus the estimated 95% removal would occur at 0.82 traps/ha. These results suggest that substantial reduction of M. galloprovincialis abundances might be achieved via mass trapping and that this represents a very promising management method for the containment or eventual eradication of B. xylophilus at the areas affected by the PWD.
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| 3. |
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| 4. |
- Echeveste, Iñaki
(författare)
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Optimization of traps for live trapping of Pine Wood Nematode vector Monochamus galloprovincialis
- 2015
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Ingår i: Journal of Applied Entomology. - : Wiley. - 0931-2048 .- 1439-0418. ; 139, s. 618-626
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 5. |
- Echeveste, Iñaki
(författare)
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Physiological development and dispersal ability of newly emerged Monochamus galloprovincialis
- 2016
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Ingår i: Entomologia Experimentalis et Applicata. - : Wiley. - 0013-8703 .- 1570-7458. ; 161, s. 141-151
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Tidskriftsartikel (refereegranskat)abstract
- Novel associations between exotic pathogens and native insects may result in major ecological and economical losses. In Europe, Monochamus galloprovincialis (Olivier) (Coleoptera: Cerambycidae) is the only known vector of the exotic pine wood nematode Bursaphelenchus xylophilus (Steiner & Buhrer) Nickle (Nematoda: Aphelenchoididae), the causal agent of pine wilt disease (PWD). Transportation of goods containing nematode-infested beetles is the main pathway for the spread of the disease. In this scenario, management actions involving early detection and eradication are critical to stop further spread by the vector. Although dispersal of mature M.galloprovincialis has been successfully tracked using commercial baits and traps, dispersal ability of immature individuals is poorly understood. Sexual maturation and other physiological traits related to dispersal were studied for newly emerged M.galloprovincialis after different shoot-feeding spans. Sexual maturation was complete after on average 12 (males) or 13 (females) feeding days. Monochamus galloprovincialis adults emerged with an average of 10% lipid and 23.8% (males) or 29.9% (females) pterothorax muscle content, and these percentages did not change significantly during shoot feeding. Microtomography images of wing muscle structures at different maturation stages confirmed these results. Emerged adults that were kept unfed survived an average of 12days in the lab. The ability of unfed immature insects to fly through hostless terrain was studied by marking and releasing newly emerged insects from a crop area located up to 3km away from two small pine stands. The longest flown distance recorded was 2km. Fitted regressions indicated that immature insects could have travelled up to 3109m to reach the experimental stands. We found that M.galloprovincialis emerge with well-developed thoracic muscles and energy reserves that enable them to sustain long flights over non-forested areas. These findings should aid managers and policy makers in devising sound procedures in areas where the risk of introducing PWD is high.
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