Acceptance and suitability of novel trees for Orthotomicus erosus, an exotic bark beetle in North America

Abstract

To predict whether an herbivorous pest insect will establish in a new area, the potential host plants must be known. For invading bark beetles, adults must recognize and accept trees suitable for larval development. The preference-performance hypothesis predicts that adults will select host species that maximize the fitness of their offspring. We tested five species of North American conifers and one angiosperm for adult acceptance and suitability for reproduction of the Mediterranean pine engraver, Orthotomicus erosus (Wollaston). Red pine, Pinus resinosa Aiton, and white spruce, Picea glauca (Moench) Voss, were accepted by adult beetles and suitable for reproduction to the extent of adult replacement. Others, such as balsam fir, Abies balsamea (L.) Mill., eastern hemlock, Tsuga canagensis (L.) Carrière, and tamarack, Larix laricina (Du Roi) Koch, were acceptable but unsuitable. The presence of tree species that are acceptable to adults but unsuitable for reproduction may affect the ability of O. erosus to establish across North America.

Future danger posed by fungi in the Ophiostomatales when encountering new hosts

“…Hofstetter et al 2013). Fungal species associated with boring beetles are not likely to easily encounter new, distantly related, hosts as the beetles tend to be specific towards certain hosts at the plant family or plant genus level (Smiley and Moser, 1974;Price et al 1992;Klepzig et al 2001;Walter et al 2010;Hofstetter et al 2013). However, chances of encountering new hosts by boring-beetle associated…”

Boring in Response to Bark and Phloem Extracts From North American Trees Does Not Explain Host Acceptance Behavior ofOrthotomicus erosus(Coleoptera: Scolytidae)

“…A laboratory colony of O. erosus was maintained on cut logs of red pine, Pinus resinosa Aiton (Ϸ50 cm long by 15Ð 40 cm diameter), in a growth chamber at 25ЊC, 16:8 L:D as described previously (Walter et al 2010a). Because beetles in the colony tended to continuously reinfest the same brood log (Walter et al 2010a), beetles were extracted from the colony by peeling the bark and phloem of the red pine logs with a draw knife and manually removing the beetles.…”

“…Because beetles in the colony tended to continuously reinfest the same brood log (Walter et al 2010a), beetles were extracted from the colony by peeling the bark and phloem of the red pine logs with a draw knife and manually removing the beetles. Beetles from the colony were used the day after they were extracted.…”

“…Adult beetles will also accept bark and phloem samples of eastern hemlock, Tsuga canadensis L. Carriè re, and balsam Þr, Abies balsamea L. Mill., as hosts, but neither of these species support reproduction (Walter et al 2010a). If the beetle accepts North American tree species that do not support its reproduction, it may be less likely to establish populations where those tree species are present.…”

“…; and Douglas-Þr, Pseudotsuga menziesii (Mirb.) Franco; a minor amount of reproduction can also take place on tamarack, Larix laricina (Du Roi) Koch (Lee et al 2008, Walter et al 2010a. Adult beetles will also accept bark and phloem samples of eastern hemlock, Tsuga canadensis L. Carriè re, and balsam Þr, Abies balsamea L.…”