Abstract:
The Asian Citrus Psyllid (ACP) (Diaphorina citri Kuwayama, 1908) (Hemiptera: Psyllidae) is a major citrus pest.
The species has been introduced to West and East Africa, but has not yet spread to southern Africa, where it
could have a devastating impact on citrus farming and livelihoods. A proactive response is key to mitigating the
species’ impacts, particularly the ongoing monitoring of potential invasion routes and entry points into South
Africa. Species distribution models (SDMs) were developed under current and future climates for ACP in Africa,
and these models were used to (1) determine where the species likely poses a threat, (2) identify potential
invasion routes into South Africa, and (3) assess how these factors will be affected under climate change. The
SDMs indicated that there is an almost contiguous band of suitable climate along the east coast of Africa that
joins the species’ current range in East Africa to South Africa, and under aggressive climate change a potential
route of invasion through Namibia and Botswana. Much of South Africa is climatically suitable for the species,
but under climate change, climatically suitable areas are likely to shift further inland. The spread of ACP into
South Africa is unlikely to be prevented, but the outputs of the present models will inform monitoring activities
and assist with preparations to respond to this predicted biological invasion.
