Biological control of the millet head miner Heliocheilus albipunctella in the Sahelian region by augmentative releases of the parasitoid wasp Habrobracon hebetor: effectiveness and farmers’ perceptions

Abstract

On-farm augmentative releases of the parasitoid Habrobracon hebetor (Say) for controlling the millet head miner (MHM) Heliocheilus albipunctella (de Joannis) was experimented in Burkina Faso, Mali and Niger from 2007 to 2009. In addition, a survey of farmers' perceptions of insect pests, with particular focus on MHM, and the biological control program (BCP) was carried out. Our findings indicate a significant increase of MHM parasitization rate after the releases with up to 97% mortality. The survey on farmer's perceptions revealed a fair knowledge of the MHM and the ability of farmers to describe the pest and its damage. Farmers claimed that the biocontrol agent H. hebetor is effective and perceived a significant gain in grain yield due to this control strategy. Implications of these findings for a large extension of the MHM biocontrol program are discussed.

Gestion de la chenille mineuse de l'épi du mil par des lâchers du parasitoïde Habrobracon hebetor Say au Niger

“…Pour les deux années, il a été noté une augmentation moyenne des taux de parasitisme de la MEM variant de 168 à 1398 % consécutive au lâcher de H. hebetor. Le dispositif mis en place a donc contribué à la mortalité des larves de la MEM, comme déjà démontré par Ba et al (2013) et Baoua et al (2014.…”

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

“…Typically, the MHM moth lays eggs on emerging panicles (Gahukar et al 1986) and it takes two weeks for the parasitoid progeny to disperse from bags after deployment . This timing coincides with the growth of MHM into third and Though the ability of farmers to describe crop insect pests (Ochou et al 1998;Tefera, 2004;Poubom et al 2005;Abtew et al 2016), including pearl millet insects and the MHM life cycle (Tanzubil and Yakubu 1997;Ba et al 2013), has been well documented in Africa, egg scouting by farmers would require some specific training (Silvie et al 2001;Gautam et al 2017). Also, scouting for eggs could be time consuming.…”

“…In each release village, the parasitoid bags were evenly distributed within five pearl millet fields (three bags per farmer's field) using the method described by Ba et al (2014). The jute bags were suspended to the ceiling of traditional straw granaries located in farmers fields and emerging parasitoids were able to escape through the jute mesh and straw granaries and disperse to parasitize MHM larvae in millet fields (Ba et al 2013(Ba et al , 2014. In each village the bags were evenly distributed to five farmers (three bags per farmer), one in the center of the village and one in each direction (E, W, N and S) with each of E, W, N and S farm 500 m away from the farm in the center of the village (Ba et al 2014).…”

“…Biological control has emerged as the most attractive solution for controlling the MHM and the gregarious parasitoid Habrobracon (= Bracon) hebetor Say (Hymenoptera: Braconidae) is considered a natural enemy with great biocontrol potential (Gahukar et al 1986;Bhatnagar 1987). Recently, augmentative releases of H. hebetor have been successful against the MHM in Niger (Payne et al 2011;Ba et al 2013Ba et al , 2014Baoua et al 2014Baoua et al , 2018. This has led to parasitism of up to 80% of the MHM larvae (Ba et al 2013(Ba et al , 2014, resulting in 34% increase in grain yield .…”

“…Recently, augmentative releases of H. hebetor have been successful against the MHM in Niger (Payne et al 2011;Ba et al 2013Ba et al , 2014Baoua et al 2014Baoua et al , 2018. This has led to parasitism of up to 80% of the MHM larvae (Ba et al 2013(Ba et al , 2014, resulting in 34% increase in grain yield .…”