Preference of an exotic wood borer for stressed trees is more attributable to pre‐alighting than post‐alighting behaviour

Abstract

1. Different mechanisms mediate host selection by insects before (prealighting) versus after (post-alighting) landing on potential hosts, but few studies distinguish pre-and post-alighting behaviour, particularly for wood borers.2. This study evaluates pre-and post-alighting host selection by Tetropium fuscum (F.) (Coleoptera: Cerambycidae), a Palearctic wood borer that was recently introduced to Halifax, Nova Scotia.3. We evaluate whether T. fuscum select stressed (i.e. girdled) over healthy red spruce, Picea rubens Sarg. (Pinaceae), trees for oviposition, as predicted by the preference-performance hypothesis (PPH). The landing rates of the native congener, Tetropium cinnamopterum Kirby (Coleoptera: Cerambycidae), and parasitoids of Tetropium spp. were also quantified.4. Tetropium fuscum consistently preferred girdled over healthy trees. Adults landed more than 10 times more frequently (11.0 ± 1.5 versus 0.6 ± 0.2 adults per tree), and females laid more than 3 times as many eggs (130 ± 23 versus 38 ± 13 eggs per bolt), on girdled compared with healthy trees. As T. fuscum survival and rate of development is greater on girdled than on healthy trees, these results support the PPH.5. Tetropium fuscum rarely made maladaptive choices pre-alighting, but postalighting oviposition on hosts on which performance is relatively lower was more common. Selection of high-quality (e.g. girdled) hosts by female T. fuscum is therefore more attributable to pre-alighting than post-alighting behaviour.

Suitability of eastern pines for oviposition and survival of Sirex noctilio F.

“…The PPH was supported among oligophagous insects that, like S . noctilio , live and feed as larvae in woody tissues, such as the emerald ash borer ( Agrilus planipennis ) [45], the eucalyptus longhorned borer ( Phorocantha semipunctata ) [46], and the brown spruce longhorn beetle ( Tetropium fuscum , stressed vs. healthy hosts of same species) [47]. In a polyphagous wood-boring insect, the Asian longhorned beetle ( Anoplophora glabripennis ), females only sometimes chose the host that also conferred optimal larval survival [48].…”

Considering species richness and rarity when selecting optimal survey traps: comparisons of semiochemical baited flight intercept traps for Cerambycidae in eastern North America

“…The Asian longhorned beetle [ Anoplophora glabripennis (Motschulsky)] has successfully established on hardwood trees in urban areas in North America and Europe (Haack et al , ) and recently was documented in forested environments (Dodds & Orwig, ). Tetropium fuscum (F.) has successfully established in spruce forests in Nova Scotia, Canada, where it threatens stressed and weakened spruce (Flaherty et al , , ). Phoracantha semipunctata (F.) and Phoracantha recurva Newman have caused considerable damage to exotic eucalypts planted in California (Paine & Millar, ).…”

Evaluating Seasonal Variation in Bottom-Up and Top-Down Forces and Their Impact on an Exotic Wood Borer,Tetropium fuscum(Coleoptera: Cerambycidae)

“…This species has been present in Atlantic Canada since at least 1990 (Smith and Hurley 2000) and although all native spruces are commonly attacked, its primary host in this region is red spruce, Picea rubens Sargent (Smith and Humble 2000). T. fuscum prefer to land and oviposit on stressed compared with healthy red spruce in North America (Flaherty et al 2013), but previous studies suggest that they can attack and kill apparently healthy trees (Smith and Humble 2000). In Europe, T. fuscum is usually reported to have one generation per yr, but may take 2 yr to develop in cooler climates (Schimitschek 1929, Juutinen 1955.…”