Assessment of an eco-friendly diatomaceous earth collar trap for controlling pine processionary caterpillars Thaumetopoea pityocampa (Lepidoptera: Notodontidae) (Denis and Schiffermüller, 1775)

This study contributes to the understanding of the insecticidal activity of diatomaceous earth against pine processionary caterpillars in the Thniet El Had National Park, Tissemsilt, Algeria. A number of factors influenced this decision, including the fact that it is a dangerous bug of the Aleppo pine that slows tree growth and poses a health risk to the general people. The microscopic structure of diatomaceous earth revealed a porous structure, demonstrating its water absorption capacity. We tested the effectiveness of diatomaceous earth against caterpillars in petri dishes in the laboratory, and we tested the effectiveness of our diatomaceous earth trap in the field. For the results in the laboratory, the insecticidal activity of diatomaceous earth on caterpillars showed highly significant results, with a lethal concentration 50 of 11.14 mg/cm² and lethal concentration 90 of 14.23 mg/cm². The study of the average mortality of caterpillars showed an increase according to the doses of diatomaceous earth used, as shown by an ascending curve to give the maximum mortality value (10 individuals per repetition) for the dose of 15 mg/cm² after 120 hours of exposure to diatomaceous earth. The application of the diatomaceous earth trap on the field resulted in a mortality rate of 50% of caterpillars, 42.86% of living caterpillars, and 7.14% of pupae. These results indicate that the tested diatomaceous earth can be a solution against this pest, and the diatomaceous earth eco-trap (collar) for pine and cedar processionary caterpillars is considered an excellent integrated pest management tool, non-toxic and environmentally friendly.