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[Display omitted] • Two invasive click beetle pest species have established in southwestern British Columbia. • Surveys conducted in 2017–2019 reveal both species have now dispersed widely. • Crop damage, displacement of native species, and continued spread is expected. • Several native, non-pest species are attracted to the pheromone of these pests. Two European click beetle species, Agriotes obscurus L. (AO) and A. lineatus L. (AL) have become serious pests of agriculture in the Fraser Valley and Vancouver Island areas of British Columbia (BC), but prior to the start of this survey (2017) it was unknown if they had established elsewhere in the Province. Pitfall traps baited with sex pheromone of AO and AL were placed throughout BC in 2017–2019 and collected a total of 4,988 AO and 20,103 AL beetles in 150 trap pairs. Both species were found to be distributed throughout southern BC, including high numbers in Creston, Kelowna, Pemberton, and Salmon Arm. Traps placed in northern BC, northern Alberta, northern Idaho, or the Willamette valley in western Oregon did not collect AO or AL. Traps were also deployed for A. sputator L., a related European species that has become a serious pest of potato in eastern Canada, but this species was not collected. AO and AL traps placed in the Pemberton valley of BC also collected 474 A. ferrugineipennis (LeConte), and traps placed in the northern Okanagan valley collected 75 A. oregonensis Becker. Both are native Agriotes species not closely related to AO or AL; this is the first time A. oregonensis was collected in Canada. We discuss the potential implications of the spread of AO and AL to other agricultural areas in BC and beyond. [ABSTRACT FROM AUTHOR]

Abstract: A study was conducted to determine the attractive range of traps baited with Agriotes obscurus pheromone to male beetles in both still air and wind conditions. This information is crucial for evaluating the potential of mass trapping when aiming to reduce beetle populations. Groups of 10 beetles were released at 14 points spaced 1 m apart along a linear track, at one end of which was a pheromone and wind source. Beetle response to the pheromone and/or wind was recorded 150 s after release and characterized as orienting either towards or away from the pheromone and/or wind source. Data analysis indicated the attraction range of the sex pheromone is <5 m in still air, which is considerably lower than estimates from previous studies and emphasizes the challenge of mass trapping this species in the field. The attraction range increased when there was air flow. Unexpectedly, not all male beetles respond to the pheromone, and beetles are inclined to move downwind even in the presence of pheromone. The latter finding suggests that wind direction may influence beetle dispersal and mate finding in the field. The implications of these results for determining the efficacy of mass trapping as a management approach are discussed. [ABSTRACT FROM AUTHOR]

A study was conducted to determine whether arrays of pheromone traps could be used to reduce populations of male Agriotes obscurus ( AO) and Agriotes lineatus ( AL) adults in a confined nonfarmed habitat (grassy dyke)., Traps placed 3 m apart in 15 × 2 arrays captured significantly more AL than AO, although the trap catch varied with location for both species and was inversely related to the number of nearby competing traps., Models of beetle movement indicated that a considerable proportion of males ( AL: 18.4-71.8%; AO: 35.0-58.3%) collected in the arrays had moved in from elsewhere and that AL beetles are more active than AO beetles. AL beetles frequently entered AO traps unless both trap types were present in the array, whereas AO rarely entered AL traps., Concurrent catches in pitfall traps placed inside and outside pheromone trapping zones indicated the trap arrays significantly reduced male (but not female) AO and AL beetles inside their respective arrays, that AO traps reduced AL beetles in AO arrays, and that both AL and AO traps could potentially reduce the number of mating pairs in these arrays., The implications of these results in determining the efficacy of this approach as a click beetle management approach are discussed. [ABSTRACT FROM AUTHOR]

The present study was conducted using mark-released populations of male Agriotes obscurus ( AO) and Agriotes lineatus ( AL) adults to simulate the spatial and temporal capture rates of wild beetle populations in dense arrays of pheromone traps in a confined, nonfarmed habitat., Two parallel rows of traps, spaced 3 m apart along corridors of grassy dyke, recaptured 85.6% of AO and 77.8% of AL with arrays of their respective pheromone traps, mostly within the first week of release. In arrays of mixed AO and AL traps, recapture rates were 77.8% and 83.3%, respectively., In arrays with only AO traps, 31.2% of AL males released within the arrays mistakenly entered the AO traps, which declined to only 2.2% when released in arrays with both AO and AL traps. In arrays with only AL traps, only 0.7% of released AO were mistakenly taken in the AL traps, and only 0.3% mistakenly entered AL traps in mixed AO and AL trap arrays., Between 34.4-38.9% of AO and 21.1-25.6% of AL released in areas immediately adjacent to the trapping arrays were caught, mostly in the outermost traps., The implications of these results for determining the efficacy of mass trapping as a click beetle management approach are discussed. [ABSTRACT FROM AUTHOR]

Copyright of Phytoprotection is the property of Society for the Protection of Plants and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

1 The production of new insect pheromones for pest monitoring proceeds at a greater rate than their evaluation, with the consequential possibility of premature introduction. Fundamental to their successful deployment is the determination of a consistent relationship between adult male pheromone trap catches and pest damage. In the present study, adult pheromone traps and larval bait traps were used to examine spatial relationships between two species of Agriotes beetle and wireworms at the field scale. 2 The spatial distributions of adult male Agriotes lineatus and Agriotes obscurus in two fields were determined and compared with the distribution of their larvae. Data were assembled as spatially referenced trap counts, and analysed for evidence of aggregation and clustering using Spatial Analysis by Distance IndicEs (SADIE) methodology. Spatial stabilities of adult populations between sampling dates were tested using association tests. Spatial and quantitative linkages between adult and larval trap catches were also tested. Moreover, a new way of adapting SADIE methodologies is presented for situations where two datasets within an area do not share the same sampling points. 3 There was no significant difference in variance : mean relationships for the two species but there were differences in their spatial distributions, and this is a definitive example of the general argument stating that it is important to consider spatial as well as count data in ecological studies. The spatial distribution of A. lineatus varied between sampling occasions at both sites whereas A. obscurus had consistently significant SADIE indices over time at one site, and adult catches could also be linked to larval distributions and counts. It is proposed that observed differences between the two species can be explained by interference between traps and dissimilar movement rates. There was some evidence of an edge effect at the field boundaries. 4 The distance between pheromone traps is related to the time that elapses before adjacent traps interfere with trap captures and this limits the detection of statistically significant spatial patterns. It is shown that the current practice of adding trap counts for different Agriotes species and treating them as numerically equivalent is insufficiently robust to be recommended at this stage. 5 The implications for the use of sex pheromone traps in wireworm pest management are considered. It is concluded that pheromone traps, as currently used, will not reliably indicate where wireworms occur in a field, and that the complexity of interpreting adult male trap counts limits quantitative predictions of population size. [ABSTRACT FROM AUTHOR]

Copyright of Phytoprotection is the property of Society for the Protection of Plants and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Agriotes obscurus (L.) wireworms assembled in increasing numbers at rows of treated (Agrox DL Plus seed treatment) and untreated wheat, Triticum aestivum L., planted at increasing densities (0,0.15,0.30, and 0.60 seeds/cm). In treated wheat plots at all planting densities, no wireworm damage to seedlings was apparent, and total wireworms taken in core samples in wheat rows increased according to the asymptotic equation y = B0(1 -e-Blx), where B0 is the asymptote, Bi is the slope of the initial rise, and x is the seeding density. The number of dead wireworms in treated plots increased linearly and intercepted the asymptotic models (theoretical point at which 100% mortality of assembled population occurs) at 0.95 seeds/cm on 11 June and 1.14 seeds/cm on 18 June 1996. Untreated wheat at all densities planted had severe wireworm damage and significantly reduced stand. Populations that had assembled at the surviving untreated wheat were fewer than in the treated wheat plots, and although increasing with seeding density, did not follow the asymptotic model. The data suggest that A. obscurus populations can be assembled and killed in fallowed fields in large numbers at treated trap crops of wheat over a 19-d period when planted in rows spaced 1 m apart at a linear seeding density of 1.5 seeds/cm. [ABSTRACT FROM AUTHOR]

Dusky wireworms, Agriotes obscurus (L.), aggregated in similar numbers at wheat [Triticum aestivum L. (Gramineae) 'Max'], oat [Avena sativa L. (Gramineae) 'Walderen'], barley [Hordeum vulgare L. (Gramineae) 'Verdin'], and fall rye [Secale cereale L. (Gramineae) 'Wheeler' and 'Prima'] cultivar bait stations containing 100 seeds planted 3 cm deep in 127-cm² circular bait stations. Similar levels of aggregation also occurred at 11 varieties of wheat planted at 100 seeds/127 cm². When wheat, oat, barley, and the fall rye cultivars were planted at increasing density (0-180 seeds per bait station), aggregation by A. obscurus increased initially, but reached a plateau at numbers and at seeding rates specific to each grain variety as determined using the asymptotic equation y = B0(1 - e[sup -Bx]). Except for barley, this equation predicted wireworm densities within 11% of the densities actually observed at bait stations with 100 seeds/127 cm². It was concluded that any of the wheat, oat, barley, or fall rye varieties would be suitable for monitoring A. obscurus wireworm populations if planted in bait stations at 100 seeds/127 cm², as well as for aggregating wireworms by means of a trap crop. [ABSTRACT FROM AUTHOR]