Stimulating effect of bark polar fraction from the terminal leader of Norway spruce, Picea abies, on white pine weevil, Pissodes strobi, feeding and oviposition

Abstract

The objective of the study was to demonstrate the importance of bark polar fraction from Norway spruce [Picea abies (L.) Karst.] terminal leaders on the feeding activity and oviposition process of the female white pine weevil, Pissodes strobi (Peck). The bark polar fraction was extracted with a ternary solvent [chloroform, methanol and water (12 : 5 : 3)]. This extracted fraction was added, at different concentrations, to an artificial diet on which mated female white pine weevils could feed and oviposit. The bark polar fraction of Norway spruce terminal leaders promoted white pine weevil oviposition compared with untreated artificial diet. The results of this study contributed to the development of an efficient artificial rearing substrate required to better understand the interactions between white pine weevil and its host plants. The importance of more specific compounds found in the polar fraction could eventually help produce more resistant trees.

Genetically based resistance to the white pine weevil in jack pine and eastern white pine

“…Genetically based resistance of spruces to WPW has been attributed to high resin canal density (Alfaro et al 1996b, Boucher et al 2001a, induction of traumatic resin canals after wounding (Alfaro 1995, Tomlin et al 1998, chemicals that adversely affect weevil reproduction (Sahota et al 1994), budburst phenology (Hulme 1995, Alfaro et al 2000 and other mechanisms (e.g., Nicole et al 2006, Lippert et al 2007. Although the mechanisms responsible for resistance of pine trees to WPW remains to be determined, it is probably also related to characteristics of leaders.…”

Behavioral and Reproductive Response of White Pine Weevil (Pissodes strobi) to Resistant and Susceptible Sitka Spruce (Picea sitchensis)

“…However, it is unlikely that an effect on the physiology of ovary development or ovary regression is the only defense mechanism in the resistant H898 Sitka spruce genotype, since male weevils were also able to distinguish between resistant and susceptible trees in the presence and absence of females; and females were highly mobile, but showed low initial feeding on the resistant leader tissue in the no-choice experiment. We also showed that feeding punctures did not correlate with the number of surviving larvae [ 28 ]. Thus, interference with egg viability and larval development was likely to be another major factor in the resistance of the resistant H898 genotype.…”