Fecundity of The Pine Processionary, Thaumetopoea Pityocampa (Denis & Schiffermüller, 1775) In The Case Of Reforestation In Moudjbara (Djelfa - Algeria)

Abstract

A study of the fecundity of female populations of the pine processionary in the Moudjbara reforestation indicates that there are cyclical variations in the reproduction of this species. Descriptive analysis of pine processionary oviposition lengths showed greater significance for oviposition deposited on needles than for oviposition deposited on twigs. A very highly significant difference was noted between the lengths of the egg-laying supports from the Moudjbara reforestation (p=0.0001). The 195 pine processionary oviposition sites revealed a total of 37,272 eggs, with an average of 191 eggs per oviposition site. Analysis of the variance between the various categories of eggs showed a highly significant probability (p=0.0001). Three parasitoids were identified that emerged from oviposits collected at the Moudjbara reforestation site, with rates varying from year to year. T. embryophagum was encountered only sporadically in 2018, 2019 and 2021, with respective percentages not exceeding 2%. For the four pine processionary caterpillar populations studied, B. servadeii appeared to be more abundant than O. pityocampae. The number of B. servadeii adults observed reached 83.91% in 2020. Parasitoid activity was greater on eggs located at the ends of the clutch. It also appears that O. pityocampae mainly parasitizes the upper part of the egg, whereas B. servadeii shows a preference for the lower part.