Population Monitoring of Pine Processionary Moth (Thaumeto poea pityocampa) by Pheromone Trapping at the Southern Limit of Distribution of Pinus halepensis in Eastern Algeria

We monitored emergence dates of adults in order to assess local population density and to determine the life cycle of the Pine Processionary Moth (Thaumetopoea pityocampa Denis & Schif.). A series of 126 pheromone traps were placed randomly on trunks of Aleppo pine (Pinus halepensis) located in the major forests of Batna City (North-eastern Algeria). We harvested daily contents of traps installed at an average height of 1.70 +/- 0.30 m, where a total of 19,339 males were captured from July 2008 to August 2008 with an average catch of 153.5 +/- 179.4 per trap. Thus, pheromone traps provided an important tool to assess population density and rhythms of adult flight. In addition, different findings are discussed such as main factors influencing adult emergence. This study was based on the use of mating disruption by mass trapping to limit future outbreaks on the one hand, and to provide data on the exact dates of adult emergence to monitor future outbreaks and to use the appropriate control technique on the other hand. Canonical correspondence analysis (CCA) showed that site variables that best explained the data were tree age and average stand height. CCA analysis indicated that altitude was not significant parameter. Factors leading to late adult emergence as well as PPM low densities in some forest stations are discussed.