Characterisation of Interactions between an Emerging Pest in France – the Poplar Woolly Aphid – and its Host Tree (Abstract)

Autor: Stéphanie Bankhead-Dronnet, Aurélien Sallé
Rok vydání: 2018
Předmět:
Zdroj: Revue forestière française
Revue forestière française, AgroParisTech, 2018, 70 (6), pp.641-642. ⟨10.4267/2042/70314⟩
ISSN: 1951-6827
0035-2829
DOI: 10.4267/2042/70314
Popis: International audience; The poplar wooly aphid, Phloeomyzus passerinii, has recently become a main pest for poplar stands in France. Following pullulations of this insect, growth retardation is observed, sometimes with massive mortality amongst mature trees. Observed initially in southwestern France in the mid 90s, damage was later observed in other poplar tree growing areas in France. The research conducted by the Laboratoire de Biologie des Ligneux et des grandes Cultures [Woody Plant and Field Crop Biology Laboratory] aimed at: — identifying the factors that caused the emergence of this pest, — understanding the nature of the interactions between the insect and its host tree and the process that leads to the latter’s death, — the mechanisms involved in the susceptibility/resistance of a number of poplar cultivars. The existence of a certain genetic diversity of P. passerinii that is spatially distributed over the whole of France refutes the hypothesis that a particularly aggressive strain of aphid has progressed northwards. Modelling work suggests that this progression is more likely a consequence of the combined effects of global warming and of large-scale plantations of susceptible poplar cultivars. A study in detail of the interactions between the aphid and its host showed that the insect generates galls on the bark of infested poplar trees. Formation of galls harnesses a considerable amount of the tree’s resources, which can then affect tree growth and survival. It has indeed been observed that infestation clearly reduces the starch content of the trees’ bark and this is correlated with stunted growth and mortality of those trees. To gain an understanding of the mechanisms involved in resistance, it was first necessary to devise a laboratory susceptibility test on the basis of existing tests. Cultivars were classified in three susceptibility categories on the basis of parameters related to the development of the insect. Behavioural, histological and molecular approaches were then used to attempt to understand the processes leading to various susceptibility statuses. The ability to partially or fully block the gall is thought to explain some cultivars’ resistance. Applications based on this work for the purpose of predicting damage are currently being developed.
Databáze: OpenAIRE