The millet Head Miner (MHM), Heliocheilus albipunctella (Lepidoptera: Noctuidae), is the most important pest of the millet crop in the Sahel. Augmentative biological control was successfully tested in the Sahel for controlling the MHM with releases of the egg parasitoids Trichogrammatoidea armigera Nagaraja (Hymenoptera: Trichogrammatidae). However, mass production of adult T. armigera at the proper moment to respond to the pest outbreak remains challenging. The study aimed to optimize the T. armigera mass rearing technique by determining the minimum sterilization time for Corcyra cephalonica Stainton (Lepidoptera: Pyralidae) eggs used as the fictitious host of the parasitoid. 24-h-old eggs of C. cephalonica were exposed to Ultraviolet (UV) radiation for 15 to 55 min and to cold (4 °C ± 0.5) for 24 to 120 h, to determine the minimum duration of egg abortion for each method. The results showed that C. cephalonica eggs can be sterilized using UV radiation (285–395 nm) and cold (4 °C) for 45 min and 96 h, respectively, without affecting the host suitability for parasitism. Sterilized eggs appeared to be more parasitized by T. armigera females than unsterilized eggs. The parasitism rate of T. armigera parents was influenced by sterilization. However, the hatching rate and the sex ratio were not significantly influenced. In the first generation (F1), the parasitism rate and hatching rate were not influenced by sterilization. However, cold-sterilized eggs produced more offspring with more females. This study contributed to the optimization of mass rearing of T. armigera and could make biological control of H. albipunctella more operational by using augmentative releases.

Ultraviolet · Cold · Corcyra cephalonica · Trichogrammatoidea armigera · Burkina Faso