Dispersal of Pissodes strobi in putatively resistant white spruce in Vernon, BC

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 ...

Methods for Marking Insects: Current Techniques and Future Prospects

“…Individual insects were marked with paint or ink using simple numbering systems (64, 93,143,185,193) or elaborate coding systems (25,158,178,225). For example, late-instar larvae of the nymphalid Euphydryas ( = Occidryas) editha bayensis were marked by strategically placing three dots of paint on each side of the larvae.…”

Population dynamics of the white pine weevil, Pissodes strobi, infesting jack pine, Pinus banksiana, in Ontario, Canada

“…Specific mortality factors have been measured for shorter time periods in other studies (Taylor, 1929;Sullivan, 1961;Alfaro & Borden, 1980;Hulme, 1990;Bellocq & Smith, 1994), but none of these measures was related to changes in the abundance of the population, so their relative importance to population dynamics of P. strobi remains uncertain. The available evidence suggests that within a fairly wide period of susceptibility of trees to attack by weevils (up to 30 years), there is significant variation in the incidence and duration of weevil attacks associated with a variety of natural mortality factors as mentioned above, as well as putative resistance of some tree genotypes (McIntosh et al, 1996), and site characteristics of the infested trees (Archambault et al, 1993;Hulme, 1995…”

Broadleaves in the Interior of British Columbia: Their extent, use, management and prospects for investment in genetic conservation and improvement

“…broadleaves in mixed stands include limiting spread of root disease among conifers (Morrison et al 1988, Gerlach et al 1997, reducing the risk of conifer attack by weevils and spruce budworm (Taylor et al 1994, McIntosh et al 1996, protecting understory conifers against frost (Andersson 1985, Pritchard andComeau 2004), providing habitat for ungulates, small mammals and birds (Peterson et al 1997, Aitken et al 2002, and improving soil productivity through nutrient-rich litter inputs (Brockley and Sanborn 2003). In keeping with this last point, total yield (conifers plus broadleaves) in mixed forests has sometimes been higher than in pure coniferous forests because of niche complementarity (Kenk 1992, Mielikainen 1996, Frivold and Kolström 1999, Man and Lieffers 1999, Valkonen and Valsta 2001.…”