Pine Processionary

The pine processionary, Thaumetopoea pytiocampa, a very important pest on golf courses with pine forests, especially in southern and central Spain. It is a caterpillar, i.e. the larval stage of this lepidopteran (butterfly) with an annual life cycle. The adult individuals, the butterflies, lay their eggs at the end of summer on the apical branches of pine and cedar trees, forming nests, pockets. One month later, the caterpillars hatch, leaving the nests during the day to feed on the young shoots of needles (pine needles or leaves), until in spring they descend to the ground to bury themselves; they move to warm areas looking for an optimum temperature of 20ºC, they go in line with the female leading the procession, hence the name "processionary".

The pine species most susceptible to attack are: Pinus nigra, Pinus canariensis, Pinus sylvestris, Pinus pinaster, Pinus halapensis and Pinus pinea. 

Fighting methods :

• Traps with female sex pheromones, so that males are attracted and trapped, preventing female fertilisation. Useful method when infestation is low. To be carried out when the pupae hatch and the adults emerge, i.e. in summer.
• Manual removal of bags.
• Physical barriers. At a certain height in the pine tree, a cone is placed around the trunk, and when the caterpillars descend, they are trapped and die of starvation.
• Conventional chemical insecticides, pyrethroids such as alphacypermethrin, deltamethrin... application should be in winter, when the larvae are young.
• Biological methods, promotion of insectivorous birds such as coal tits and blue tits; use of Bacillus thuringiensis (bacteria) which produces an endotoxin, applied in autumn. After application to pine trees, it is ingested by the caterpillars and kills them.