1 Traps of four new designs were tested against the conventionally used multiplefunnel trap to determine whether trapping of large wood-boring insects can be improved in western Canada. All four new traps used a large collecting receptacle containing detergent-laced water, and three presented a prominent visual silhouette above the receptacle. 2 In total, 27 336 large woodborers were captured from 10 June to 30 September in an experiment in the southern interior of British Columbia, and 4737 from 6 June to 27 July in an experiment in northern Alberta. The woodborers captured in the British Columbia experiment were mainly beetles in the families Cerambycidae (79%) and Buprestidae (15%), and woodwasps in the family Siricidae (6%). Most woodborers, e.g. three Monochamus spp. and Xylotrechus longitarsus (the predominant cerambycids), were captured throughout the summer, with peak captures in August. 3 Cross-vane, pipe and stacked-bottomless-¯ower-pot traps were generally superior to pan and multiple-funnel traps for insects in nine taxa, but cross-vane traps were the most effective overall, trapping 32% of all insects captured. 4 The large number of target insects captured in a relatively small number of traps in the two experiments suggests that employment of an ef®cacious trap with a large vertical silhouette and a wide, escape-proof collecting receptacle could make mass trapping of large woodborers in timber processing areas operationally feasible. 5 Because the most effective traps were unstable in the wind, and the detergentlaced water captured unacceptably high numbers of small mammals, design mod-i®cations are necessary. We are currently developing a wind-®rm trap, with a prominent vertical silhouette, a wide collecting surface, and an escape-proof, but dry collecting receptacle.

Dutch elm disease is caused by the fungal pathogen Ophiostoma novo-ulmi which is transmitted by the native elm bark beetle, Hylurgopinus rufipes. We have found that four semiochemicals (the monoterpene (-)-beta-pinene and the sesquiterpenes (-)-alpha-cubebene, (+)-spiroaxa-5,7-diene and (+)-delta-cadinene) from diseased American elms, Ulmus americana, synergistically attract H. rufipes, and that sesquiterpene emission is upregulated in elm trees inoculated with O. novo-ulmi. The fungus thus manipulates host trees to enhance their apparency to foraging beetles, a strategy that increases the probability of transportation of the pathogen to new hosts.

No abstract

White pine weevil Pissodes strobi behaviour was observed in Le comportement du charanqon du pin blanc Pissodes strobi a five-year-old plantation of white spruce in Vernon, British a Ct C CtudiC dans une plantation de cinq ans d'Cpinetle blanche localColumbia. Seasonal weevil-host interactions were monitored in is& B Vernon en Colombie-Britannique. Les interactions charanqonfour susceptible and four putatively resistant reciprocal cross famh6te ant Ct-~diks chez q u m P&S susceptibles et qutre P&S ily pairs in three of five replicates. Classification of susceptibility potentiellement rksistantes issues de croisements rkciproques to weevil attack was based on previous weevil attack history.d'une m6me famille et pour trois des cinq replicats. La classifiperformance of eight reciprocal cross pairs was ranked as a cation de la susceptibilit6 B l'attaque du charanqon reposait sur function of visitation, ov~pos~t~on and brood establishment resultl'historique des prkCdentes attaques. La performance de huit des ing in top-kill, The four putatively resistant family crosses paires issues de croisements rCciproques Ctait classCe en tant que ranked 1 to 4 for resistance to weevil attack, while the four susde la prCsence, de l'emplacement des oeufs et de ceptible crosses were ranked 5 to 8 and were consistently attacked. l'emplacement des lames entdnant la mort de la flkhe. Les quatre croisements potentiellement rksistants ont Ct C classis de 1 B Seasonal and diurnal movement was using mark-4 en fonction de la resistance B l'attaque du charanqon, tandis que recapture techniques. Diurnally, weevils moved within the tree. les croisements susceptibles CtC classCs de et Feeding occurred at dawn in the leader and laterals after which conhuellement &qUCs. Les d*lacements saisonnim et ractivweevils moved down the tree into the forest floor during the high it6 dime kt6 enregistr~s selon une technique de et mkl-mnmer temperatures. Later in the season weevils fed in midde capture. Au cours de la journte, le charangon se deplace morning on the leader and on the under-sides of lateral branchdans 19arbre. ~~~l i~~~t~t i~~ se fait au cr~puscule dans la flkche es. A dispersal index was developed to describe seasonal moveterminale et sur les flkches latkrales, puis les charangons se ment. Weevils did not move far throughout the season. Overall 9 1 m t v m la base de et dans la liti& des t e m g r a m dispersal index for both males and females was less than 0.24 m, ClevCes du milieu de 1' CtC. Plus tard dans le courant de la saison, suggesting that on average, weevils do not move further than the les charanqons s'alimentent vers le milieu de la matinCe dans la adjacent tree throughout the season after mating and oviposition.flbche et sur le dessous des branches latkrales. Un indice de dispersion a Ct C ClaborC pour dCcrire les dCplacements saisonniers. Key words: Dispersal, pest management, Pissodes strobi, resis-L'indice global de dispersion pour les mgles et les femelles a Ct C tance, silviculture, white spruce de moins de 0.24 m, laissant ...

We investigated the hypothesis that wood-boring beetles in the genus Monochamus (Cerambycidae) utilize pheromones of sympatric bark beetles as host-finding kairomones. All nine bark beetle pheromones tested electrophysiologically were antenally active for both sexes of M. scutellatus, M. clamator, and M. obtusus from British Columbia. When field-tested with multiple-funnel traps (British Columbia) or cross-vane traps (Ontario), a blend composed of frontalin, ipsdienol, ipsenol, and MCH, in combination with a blend of host volatiles attracted significant numbers of M. clamator, M. obtusus, M. notatus, and M. scutellatus to baited traps. Traps baited with host volatiles in combination with a second blend composed of endo-brevicomin, exo-brevicomin, cis-verbenol, trans-verbenol, and verbenone caught no more beetles than unbaited traps or traps baited with the host blend alone. In British Columbia, traps baited with the first blend alone or both blends together captured more M. scutellatus and M. clamator than unbaited traps, demonstrating a response to bark beetle pheromones in the absence of host volatiles. These results suggest that Monochamus spp. are minimizing foraging costs by using the pheromones of sympatric bark beetles as kairomones.

No abstract

The Canadian Entomologist 131: 115 -129 (1999) Delphastus catalinae (Horn) (Coleoptera: Coccinellidae) was mass reared to support field studies addressing augmentation and colonization for control of Bemisia argentifolii Bellows and Perring (Homoptera: Aleyrodidae) in southern California. Beetles were reared on B. argentifolii infested poinsettia plants grown inside greenhouses located in northern California. Potted plants, reared from rooted cuttings, were cycled through the rearing system over ca. a 12-week period, then discarded. A total of 174 245 adult beetles were harvested over a 20-week period. Each plant averaged 46 adult beetles (range 21-89) over the same period of time. Harvesting strategies were investigated using a computer simulation model based upon published and hypothesized reproduction and survivorship parameters. Results suggest that removal of approximately 50% of adults per week produced a stable and maximum production of beetles. Actual harvest rates were between 40 and 60% of available beetles. The cost of producing each adult was estimated at US$0.22, with the major cost being labor at 86% of the total. Pickett, C.H., K.A. Casanave, S.E. Schoenig et K.M. Heinz. 1999. ~l e v a~e de Delphastus catalinae (Coleoptera : Coccinellidae): expkrience pratique et mod6lisation. The Canadian Entomologist 131 : 115-129. Nous avons procCdC B 1'Clevage en masse de Delphastus catalinae (Coleoptera: Coccinellidae) pour vCrifier les donnCes obtenues en nature sur l'augmentation et la colonisation de ces insectes destinCs B assurer le contr6le de Bemisia argentifolii, Bellows et Perring (Homoptera; Aleyrodidae) dans le sud de la Californie. Les coccinelles ont Ct C ClevCes sur des plants de poinsettia infest& de B. argentifolii en serre dans le nord de la Californie. Les plants en pot, cultivCs B partir de boutures portant des racines, ont Ct C gardCs pendant tout un cycle, soit environ 12 semaines, puis jetCs. Au total, 174 245 colCopt&res adultes ont Ct C obtenus au cours d'une PCriode de 20 semaines. Chaque plant a donne! en moyenne 46 coccinelles adultes (21-89) pendant cette pCriode. Les stratkgies de rCcolte des adultes ont Ct C exami-nCes au moyen d'un modble de simulation B l'ordinateur bask sur des parambtres de reproduction et de survie hypothCtiques ou tirCs de la littkrature. Les rCsultats indiquent que la rCcolte d'environ 50% des adultes chaque semaine assure une production stable et maximale de coccinelles. Les taux rCels de rCcolte ont Ct C de 40% B 60% des colCopt&res prksents. Le coiit de production d'un adulte a Ct C estimC B $0,22, la plus grande partie due B la main d'oeuvre (86% au total). [Traduit par la RCdaction]

Insect epidemics such as the mountain pine beetle (MPB) outbreak have a major impact on forest dynamics. In Cypress Hills, Canada, the Forest Service Branch of the Saskatchewan Ministry of Environment aims to control as many new infested trees as possible by conducting ground-based surveys around trees infested in previous years. Given the risk posed by MPB, there is a need to evaluate how well such a control strategy performs. Therefore, the goal of this study is to assess the current detection strategy compared with competing strategies (random search and search based on model predictions via machine learning), while taking management costs into account. Our model predictions via machine learning used a generalized boosted classification tree to predict locations of new infestations from ecological and environmental variables. We then ran virtual experiments to determine control efficiency under the three detection strategies. The classification tree predicts new infested locations with great accuracy (AUC = 0.93). Using model predictions for survey locations gives the highest control efficiency for larger survey areas. Overall, the current detection strategy performs well but control could be more efficient and cost-effective by increasing the survey area, as well as adding locations given by model predictions.