Timing of releases of the parasitoid Habrobracon hebetor and numbers needed in augmentative biological control against the millet head miner Heliocheilus albipunctella

Abstract

Heliocheilus albipunctella de Joannis (Lepidoptera: Noctuidae) is one of the major insect pests of pearl millet in the Sahel. The native parasitoid, Habrobracon hebetor Say (Hymenoptera: Braconidae), is currently being promoted for augmentative biological control of the pest in the Sahel. The current study was carried out to identify the right time for releases of the parasitoid using either pearl millet growing stage, or pest occurrence as reference, and to determine the optimal number of parasitoids needed to cover a given area. Our results indicate that release of parasitoids at the panicle emergence stage or sixweeks after first sight of eggs of H. albipunctella lead to highest parasitism of H. albipunctella larvae by H.hebetor. The dose of 800 parasitoids for a distance of 3 km radius was enough for controlling H. albipunctella. The implications of the results are discussed toward cost effective and practical recommendation adapted to the Sahelian conditions.

Effect of augmentative releases of the parasitoid, <i>Habrobracon hebetor</i> Say (Hymenoptera: Braconidae) using plastic cups on <i>Heliocheilus albipunctella</i> De Joannis (Lepidoptera: Noctuidae) in the Sahelian region of Burkina Faso

“…It is thus necessary to refine the H. hebetor releases technique to limit the ecological risks while maintaining the effectiveness of the biological control programme. This could be achieved by direct releases of H. hebetor adults as suggested by Amadou et al (2019), but this would be difficult when parasitoids must be transported from place to place (several tens of kilometres). For better control of MHM by H. hebetor, it is preferable to improve the current method of H. hebetor release.…”

Diets for Tamarixia triozae adults before releasing in augmentative biological control

“…Augmentative release of natural enemies, particularly parasitoids, is one of the most widely used approaches to pest biological control in annual crops and greenhouses (van Lenteren and Bueno 2003;Hoy 2008;Amadou et al 2019;Bueno et al 2020;Kazak et al 2020). It is also commonly applied to control resurgent pests resulting from disruptions of natural enemy populations by seasonal factors and harvesting activities (Hajek and Eilenberg 2018;Stenberg et al 2021) or insecticide applications (Coppel and Mertins 1977;DeBach and Rosen 1991).…”

When Does the Prey/Predator Ratio Work for the Effective Biocontrol of Cotton Aphid on Cotton Seedlings?

“…For example, natural suppression of soybean aphid in soybean was worth an average of USD 33 ha −1 [ 7 ]. Numerous technologies promoting the efficacy of biocontrol, such as selective insecticides [ 8 , 9 ], environmentally friendly bio-pesticides [ 10 , 11 ], augmentative biological control [ 12 , 13 ], habitat management [ 14 , 15 ], and genetically engineered crops [ 16 , 17 , 18 ], have been implemented in agricultural management. Conservation biological control (CBC), which integrates natural enemies back in to crop systems, can minimize the likelihood of a pest outbreak, and reduce pesticide use and pest resurgence [ 8 , 19 ].…”