Population Fluctuations of the Pine Processionary (Thaumetopoea pityocampa Schiff.) in France from 1969 to 1989

1990

3 Abb., 9 Lit. Ang.

Unselbständiges Werk

9087

200085750

The Pine Processionary is a major defoliator of circummediterranean resinous stands. During periods of pollulation, all the pinewoods of the South of France are subject to grave damage. In such cases, broad interventions are often warranted. Before 1970, the absence of insecticide preparations which could be used without risk to the forest environment and the variations of the annual cycle resulting from bioecological adaptations of the pest to the climate, explain why treatments were so sporadically implemented at the time. From 1970, a new situation arised from the commercialisation of a treatment based on Bacillus thuringiensis (Berl.) and from the publication of the works of Demolin (1969, 1970) and Huchon et Demolin (1970), which were directly applicable to the practical realm. New perspectives were opened: it was now possible to envisage a strategy of preventive microbiological interventions. For that reason, the CEMAGREF set up as early as 1969 a monitoring structure over the whole range of the Pine Processionary in France (CERAFER, 1969; CEMAGREF-INRA, 1980). The objectives of this network were to estimate the risk of infestation of the defoliator and to examine for each particular region the advisability and the optimal dates of treatment. With the data now at our disposal, we are able to present a first analysis of the population fluctuations in space and in time over the last 20 development cycles and to define more precisely the current area of distribution of the Pine Processionary in Frace.