Contact toxicity and proximate effect of fipronil on insect pest and predatory ant community structure in cocoa agro-ecosystem
Date
2023
Journal Title
Journal ISSN
Volume Title
Publisher
Journal of Agriculture and Food Research
Abstract
Although usage persists in some countries, fipronil is banned or restricted in many others. Prior to its ban on
cocoa in Ghana, concerns about its effect on non-target insects and secondary outbreak of Anomis leona were
conflicting. This study, which predates the ban, assessed the toxicity and the short-term effect of fipronil on
specific insect community structure in the cocoa agro-ecosystem alongside bifenthrin and a non-insecticide
control. Although the insecticides induced a high mortality (90-100%) on the target (mirid: Sahlbergella singu laris, stink bug: Bathycoelia thalassina and coreid bug: Pseudotheraptus devastans) and non-target (ants: Oecophylla
longinoda, Crematogaster africana, Pheidole megacephala and Camponotus consobrinus) insects, the knockdown to
fipronil was very low compared to bifenthrin. On the field, fipronil was more detrimental to the ants. Insecticide treated plots recorded relatively lower post-treatment pest diversity compared to the control, except the last
sampling month while ant abundance, richness and diversity were lowest on the fipronil-treated plots at the end
of the study period. This study demonstrates that although fipronil was effective against pests and did not result
in acute secondary pest outbreak, it was harmful to the ants. This effect could potentially be replicated on these
ant species in other cropping systems where the insecticide is used, adversely affecting ecosystem service de livery. Hence, research on its impact on non-target organisms in other cropping systems is needed to regulate and
monitor its use.
Description
Research Article
Keywords
Insecticide, Knockdown, Mirid