Inventory and Impact of Insects on Post-harvest Bulb Onions (Allium cepa) in Burkina Faso

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Résumé

Onions are one of the most important vegetable crops in Burkina Faso. However, onion producers report significant economic losses during storage, which limits year-round availability. To investigate the cause of these losses, this study aimed to identify the insects associated with onion bulbs in on-farm storage warehouses. The study was carried out in the Central Plateau Region in 4 storage warehouses. The insects were collected using yellow sticky traps and a random sample of 200 bulbs was taken from each warehouse to assess damage. A total of 11 insect species from to 10 families and 4 orders were identified. The most prevalent species were Agrotis ipsilon (Hufnagel 1766) (3077 individuals collected), followed by Delia antiqua (Meigen 1826) (2132 individuals) and Lyctocoris sp. (Hahn 1836) (138 individuals). Rotten bulbs accounted for the greatest losses, with 23.34%, 21.34%, 11.17% and 7.99% losses in Loumbila, Koassanga, Ziniaré and Poedogo, respectively. The overall loss rate was 22.84% and 30.34% in stores infested with A. ipsilon and D. antiqua, respectively. This study is the first in Burkina Faso to report the presence of insect pests in onion storage, and it deserves particular attention. These results constitute an essential step toward the developing of an appropriate control strategy to manage these insects in warehouses.

Mots-clés

Onion, Post-harvest loss, Insect pests, Agrotis ipsilon, Delia antiqua, Warehouse