The effects of short-term cold storage on the survival of the endoparasitoid Ooencyrtus pityocampae Mercet (Hymenoptera Encyrtidae).


In the Mediterranean basin the Pine Processionary Moth (PPM), Thaumetopoea pityocampa is often responsi­ble for damaging coniferous stands. The parthenogenetic thelytochous Ooencyrtus pityocampae because of its host location strategy and capacity to develop on alternative hosts plays a key role in the control of PPM. In the context of biological control, storage at low temperatures of parasitoids proved to be effective in improving their mass rearing for field release. Unfortunately, cold storage is often associated with high mortality even above the freezing tempera­ture. Therefore, the present work focused on O. pityocampae juvenile stages submitted to 10-days storage at 15°C and then transferred to 26°C and 30°C until adult hatching. Two different hatching temperatures were used to test the hypothesis whether the speeding of O. pityocampae development could affect its survival and synchronization of emer­gencies. After the treatment, adult emergence percentage, adult emergence time and synchronization of emergencies were evaluated. Results showed that all life stages successfully survived the thermal regime.

Nonetheless, pupae because of their high emergence rates and synchronization of adult hatching appeared to be the best stage for short time storage.


Thametopoea pityocampa; biological control; cold storage; endoparasitoid; Ooenyrtus pityocampae

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