Plant phenotype affects oviposition behaviour of pine processionary moth and egg survival at the southern edge of its range

Abstract

Morphological traits of Aleppo pine (Pinus halepensis) needles in native and planted stands at the southern edge of its range influence oviposition behaviour of the pine processionary moth (Thaumetopoea pityocampa). Extreme environmental conditions result in a reduction in needle size of the host plant which corresponds to a lower rate of fecundity in the moth. Our results showed that egg batches were laid closer to the needle buds, especially on native trees with short needles, and this resulted in increased egg mortality. Number of eggs laid by the female moths did not vary between native and planted stands, nor did the number of parasitized eggs of the two common Hymenopteran parasitoids, Baryscapus servadeii and Ooencyrtus pityocampae. The observed differences in egg mortality are likely due to abiotic factors associated with the position of the egg batch on the needles. Thaumetopoea pityocampa eggs require a thermal niche for optimal development, and further measurements are required to determine the thermal threshold of these eggs. Understanding the role of climate in T. pityocampa populations will be an important factor for the survival of the Aleppo pine forests and protecting it from desertification.

Abundance and impact of egg parasitoids on the pine processionary moth (Thaumetopoea pityocampa) in Bulgaria

“…The percentage of parasitism caused by O. pityocampae and B. servadeii does not depend on location of T. pityocampa egg batches on pine needles (Hezil et al 2018). Masutti (1964) pointed out that B. servadeii is more resilient and develops successfully in areas with temperatures above 30 °C, i.e., in conditions that suppress O. pityocampae development.…”

Ecological characteristics of pine processionary moth Thaumetopoea pityocampa (Lepidoptera: Notodontidae) larval nests in pine and cedar forests of Algeria

“…The PPM has a univoltine lifecycle. In Algeria, the adults emerge, mate and lay eggs in a single clutch on pine needles or the underside of cedar twigs in July at colder sites and in August at warmer sites (Hezil et al 2018;Sebti et al 2022). Each egg batch contains, on average, in the northern regions of Algeria 220 eggs covered with protective scales, which are produced by the female .…”

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

“…Despite the studies carried out on the biology and ecology of the species, its ecological behavior remains complex and under the aegis of various environmental variables (Alsanousi & Sheip 2022). Several works have been carried out in Algeria covering several aspects, namely systematics, ecology, damage and means of control against this insect (Alsanousi & Sheip 2022), (Amar et al 2014), (Sebti & Chakali 2014), (Bouchou 2015), (Boudjahem & Berchi 2020), (El Mokhefi et al 2016), (Hezil et al 2018), (Rahim & Chakali 2022) and (Rabhi et al 2023).…”