Robinson (Asteraceae) in West and Central Africa. These scenarios are exemplified by the perennial scrambling invasive alien plant Chromolaena odorata R.M. Novel environments have increasingly become susceptible to biological invasions due to human-mediated activities, encompassing movement, global trade, and climate change, and there is no apparent indication of this abating. odorata in other countries where it has established, it is expected to have a similar impact in Central Africa. Given that it has significantly reduced populations of C. Cecidochares connexa is currently the only biological control agent for C. connexa into Cameroon, we anticipate that it will continue to spread further into other parts of Central Africa which are climatically suitable. Following the spread and establishment of C. connexa from the release sites in Côte d’Ivoire into Cameroon, covering over 2,300 km. Clearly, Ghana, Togo, Benin Republic and Nigeria served as the dispersal pathway of C. connexa in two locations in Nigeria and one in Ghana, as well as its occurrence in all locations surveyed in Benin Republic and Togo. connexa, as reflected in the absent-present record of C. In West Africa, we recorded significant expansion in the geographic range of C. In Africa, these findings represent the first-ever report of C. Cecidochares connexa was present at five of the six locations surveyed in Cameroon, albeit in varying abundance. Additional surveys were conducted across four countries (Ghana, Togo, Benin Republic and Nigeria) in West Africa that we considered the probable pathway for the spread of the gall fly into Central Africa. connexa galls in Cameroon between October 2018 and October 2020, along roadsides, on farms, residential areas, and abandoned plots, encompassing various vegetation types.

This study aimed to investigate whether the gall fly had spread further across West Africa and into Central Africa. The stem-galling fly, Cecidochares connexa (Macquart) (Diptera: Tephritidae), has spread widely across West Africa since its release in only Côte d’Ivoire, occurring in six countries. Robinson (Asteraceae) is a serious weed in West and Central Africa and two biological control agents that have been introduced into West Africa to help reduce its impacts on agriculture and biodiversity, have established. The Neotropical invasive plant Chromolaena odorata R.M.

Increase in gall fly biocontrol agents