Adult Feeding Preference and Fecundity in the Large Pine Weevil, Hylobius abietis (Coleoptera: Curculionidae)

Abstract

Adult feeding preferences of Hylobius abietis on Picea abies, Larix decidua, Pinus sylvestris, Pseudotsuga menziesii, Abies alba and Betula pendula were tested in outdoor conditions. The preferred food source was P. menziesii, and the mean bark area consumed per seedling was 440.8 ± 147.9 mm2. The second most preferred host was P. abies. The coniferous species that suffered the least damage was A. alba (76.8 ± 62.56 mm2 per seedling). B. pendula was the least preferred source of food, and it caused mortality of 60% of weevils that fed on it. Weevils exhibited large differences in fecundity when fed with different tree species in a laboratory experiment. The largest number of eggs was laid by females fed with P. abies. Mean egg numbers reached 26.4 ± 24.89 eggs per experiment for P. abies. Similar fecundity was observed in weevils fed with twigs of P. sylvestris. Oviposition was approximately six times lower in females fed with L. decidua and P. menziesii. The maximum number of eggs laid by a single female during a one-month experiment was 90. The results are discussed in relation to management of H. abietis.

Trap Catch Data are Poor Predictors of Damage Caused by Pine Weevil (Hylobius Abietis) to Conifer Seedlings

“…Newly planted conifer seedlings on regeneration sites are frequently damaged and killed by adult pine weevils, Hylobius abietis (L.), feeding on their stem bark (Doležal et al 2021). This poses a major threat to successful forest regeneration in large parts of Europe, especially where forests are managed by clear-cutting followed by planting (Björkman et al, 2015;Lalík et al, 2021).…”

Hard Nut to Crack. Acorn Hardness Implications on Oviposition of the Acorn Weevil Curculio glandium Marsham, 1802 (Coleoptera: Curculionidae)

“…A study from the United Kingdom mentions 50 eggs as C. glanium female fecundity; still, the sample size was lower (n = 5) and beetles were dissected at the point in the season after which they could have produced more eggs, if still alive [32]. Fertility of other curculionids is notably higher-e.g., females of the large pine weevil Hylobius abietis (L.) deposit, on average, 70 eggs during one season [33]. A species closely related to Curculio spp., the strawberry blossom weevil Anthonomus rubi Herbst, has a mean fecundity of 157.6 eggs during a period of 71.6 days [34], whereas a rhynchocepharid, the red palm weevil Rhynchophorus ferrugineus (Olivier), can lay from 112 to 315 eggs [35].…”

Image_1.JPEG

“…compared to Norway spruce (Wallertz et al, 2014). A higher preference for Douglas fir over Norway spruce was also confirmed by Doležal et al (2021). However, pine weevil feeding scars have also been recorded on deciduous trees, such as Fraxinus excelsior L., Alnus glutinosa (L.) Gaertn., Fagus sylvatica (L.) Gaertn., Quercus robur L., Salix L.…”

“…Freshly made clear-cuts are suitable habitats for the pine weevil to breed (Solbreck, 1980). Therefore, the population of this species is expected to increase due to extensive clear-cut reforestation after bark beetle outbreaks (Doležal et al, 2021). The pine weevil is a widespread and severe pest associated with regenerated coniferous forests in northern and Central Europe (CAB International, 2003;Skrzecz, 2017).…”

“…In our study, the feeding scar intensity on pine seedlings did not differ from feeding scars on larch. Larch was also found to be attractive by Doležal et al (2021), but in their laboratory experiment, larch was preferred for almost the entire experimental period, while pine weevils started to prefer pine only during the last week of his experiment. However, it is interesting why the pine weevil prefers to eat larch, as female pine weevils feeding on larch lay far fewer eggs than females feeding on spruce or pine (Doležal et al, 2021).…”