Infestation of Glycaspis brimblecombei (Hemiptera: Psyllidae) on three Eucalyptus species in selected ecological zones in Malawi

The study determined variations in incidence, severity and damage of Glycaspis brimblecombei among Eucalyptus species and ecological zones, and the interaction between Eucalyptus species and ecological zones. Additionally, the study determined variation in pest abundance between the upper, middle and lower parts of the tree crown. The study was conducted in six districts located in four ecological zones in Malawi. Eucalyptus stands established in 2014–2016 or coppices from trees cut in that period were sampled for G. brimblecombei infestation. A significant interaction was found between Eucalyptus species and ecological zones on G. brimblecombei infestation. Significant differences were observed between ecological zones in G. brimblecombei infestation with lowest incidence, severity and damage being found in the cooler ecological zone M. Eucalyptus camaldulensis and Eucalyptus tereticornis showed high susceptibility to G. brimblecombei compared to Eucalyptus grandis. There were no significant differences in abundance between the upper, middle and lower tree crown parts of each Eucalyptus species. Control efforts for this psyllid should focus on breeding and planting of resistant Eucalyptus varieties in specifically recommended sites. The uniform distribution of the pest on different tree crown parts implies that use of contact insecticides on a large scale would be tedious and expensive.