Mitigation Measures for Invasive Insect Pests on Eucalyptus Spp. in East Africa: A Review

Abstract

Eucalyptus spp. plantation forestry is expanding rapidly to meet wood and fibre demands internationally, including in Eastern Africa (especially Kenya, Uganda and Tanzania). However, Eucalyptus spp. plantations in eastern Africa are increasingly being damaged by invasive insect pests. In particular, the Australian invasive pests; Gonipterus scutellatus complex (Eucalyptus snout beetle), Leptocybe invasa (Blue gum chalcid), Thaumastocoris peregrinus (Bronze bug), and Glycaspis brimblecombei (Red gum lerp psyllid) pose a serious threat to Eucalyptus spp. plantations in eastern Africa. This is a trend that has also been noted in other parts of Africa and globally. Factors that influence introduction, establishment and spread of Australian invasive insect pests include: the expanding planting of Eucalyptus in intensive plantations over large areas, increased human trade and transport, natural dispersal mechanisms across borders, and a growing pool of established exotic pests in the neighbouring regions. Therefore, there is increasing pressure to develop more effective management strategies for the invasive pests and more rapidly than in the past. Some of the strategies that are employed in pest management and require improvement include: strengthening phytosanitary and quarantine measures at ports of entry, selection and deployment of resistant/tolerant host tree genotypes, and international and regional collaborations to prevent the entry and management of invasive species. In this review we assess on the knowledge generated in recent studies concerning forest pests and further consider methods/policies that could be employed or improved to mitigate the threat of invasive pests associated with Eucalyptus spp. in the Eastern Africa region.