par Finet, Y.;Grégoire, Jean-Claude
Référence Journal of applied entomology, 91, 1-5, page (355-367)
Publication Publié, 1981-12
Article révisé par les pairs
Résumé : The sensibility of different Populus clones to a Chrysomelid defoliator, Phyllodecta vitellinae, has been analysed by choice experiments in a greenhouse. A first series concerned 3 clones: “Ghoy”, “Beaupré” and “Columbia River”. A second series concerned 6 clones: “Ghoy 1” (P. nigra), “Gaver”, “Robusta vert”, “Fritzy Pauley”, “Columbia River” and “UNAL”. In the two series of experiments, we recorded the number of beetles present on each plant, as well as the number of eggs. During the second series, we also made direct measures of leaf areas consumed. Moreover, in this series, marking of the insects also allowed us to study some particular aspects of their behaviour. The results are as follows:1. Insects showed significant to very significant food preferences, which did not vary significantly from one experiment to another within the same series. The order of increasing “resistance” (negative choice by the insects) was: P. trichocarpa X deltoïdes; P. deltoïdes X nigra; P. trichocarpa; P. nigra.2. There were no significant oviposition preferences, although correlation between number of eggs laid and adults' level of presence was on average good for most of the clones.3. Correlation between consumed leaf areas and beetles' level of presence was always good.4. “Long-range” (meters) orientation towards a plant was a linear function of its height.5. There was a significant linear relation between clonal preference and time spent by individual beetles on plants of the different clones.6. Feeding occurred especially on higher, younger leaves, and egg-laying on lower leaves.7. Nocturnal activity did not differ significantly from diurnal activity. There was a peak at dusk.8. Food-taking speed varies between 2 and 2,5 mm2 of foliar surface per hour per beetle, and is independant of clonal preference (although this did not appear quite so clearly for the clone P. nigra “Ghoy 1”).