Feeding behaviour of the black pine beetle, Hylastes ater (Coleoptera: Scolytidae)

Abstract

1 The feeding behaviour of Hylastes ater was investigated at 15 °C and 20 °C on a range of tree species. The role of an aggregation pheromone and the part played by olfactory cues in food selection was also investigated. 2 A distinct hierarchical preference at both 15 °C and 20 °C such that Pinus radiata > Pinus sylvestris > > Picea abies > > Rubus fruticosus = Betula pendula was shown. 3 Feeding on P. sylvestris led to the highest weight gain, closely followed by P. radiata and P. abies . Slightly elevated feeding was observed at 20 °C compared with 15 °C. 4 Reduced feeding in the presence of B. pendula suggests the possibility of an antifeedant effect and predamaged wood was found to be less nutritious, possibly due to greater plant defences. 5 The role of an aggregation pheromone was not supported. Olfactory cues enabled the detection of woody hosts, although differentiation between host was not observed. 6 These results are likely to be important in helping to design an effective integrated control approach against this pest.

Infestation Density of Eucalyptus Gall Wasp,Leptocybe invasaFisher and La Salle (Hymenoptera: Eulophidae) on Five Commercially GrownEucalyptusSpecies in Tanzania

“…A rise in temperature, within a favorable range, will speed up the metabolism of an insect and consequently increase its rate of development (Gullan & Cranston, 2005). Similarly, Leahy, Oliver, and Leather (2007) reported elevated feeding at increased temperatures among forestry pests which is likely due to the higher metabolic rates experienced at those temperatures as well as the effect of temperature and volatiles released from the wood, which might stimulate feeding. The results of this study concur with that of Protasov et al (2008) in Israel where adults of the gall wasp emerged from eucalypt foliage throughout the year in the greenhouse at a temperature range of 23-31 • C. However, field surveys in Israel by Mendel et al (2004), indicated that the wasp oviposits only during the warm season when the average maximum temperature has risen above 20 • C, and that wasps which inhabit galls in the winter may develop slowly or die depending on their developmental stages.…”

Temptations of weevil: feeding and ovipositional behaviour of Hylobius warreni Wood on host and nonhost bark in laboratory bioassays

“…Four branch sections, one from each tree species, were placed on a piece of filter paper (width 140 mm) in a square plastic container (height 50 mm, width 140 mm wide). The filter paper was moistened with 0.8 mL of distilled water to maintain humidity inside this arena (Raffa et al, 2002; Toivonen & Viiri, 2006; Leahy et al, 2007). One adult weevil, starved for 48 h previously, was placed inside the container, and allowed to feed on the four branches.…”

“…Root herbivores may cause chronic mortality through predisposition to fungal pathogens or above‐ground herbivores (Whitney, 1961; Hunter, 2001; Zhu et al, 2008) or the insects may girdle and kill young trees. Notable examples include weevils such as Hylastes ater (F.) (Coleoptera: Curculionidae: Scolytinae) and Hylobius abietis (L.) (Coleoptera: Curculionidae) in Europe (Eidmann, 1997; Leahy et al, 2007). In North America, an emerging concern in forest management is the Warren root collar weevil Hylobius warreni Wood (Coleoptera: Curculionidae), a native, flightless insect distributed transcontinentally throughout northern coniferous forests (Cerezke, 1994).…”

Bark beetles attacking conifer seedlings: picking on the weakest or feasting upon the fittest?

“…unstressed) Pinus sylvestris twigs gained significantly more weight than those feeding upon damaged (i.e. stressed) twigs (Leahy, Oliver & Leather ). Similarly, the bark beetle Tomicus destruens has been found to preferentially attack nonstressed pines during its shoot feeding phase and to have increased fitness as a result (Branco et al .…”