Susceptibility of Eucalyptus Species and Clones to Red Gum Lerp Psyllid, Glycaspis brimblecombei, (Hemiptera: Psyllidae) in Mbizi Forest Plantation, Tanzania

Glycaspis brimblecombei is a sap-sucking insect that feeds on Eucalypts. The pest is native to Australia. The nymph feeds on eucalypt leaves and secretes honeydew with which they construct a waxy cover (called a lerp) around themselves. This cover is whitish and conical in shape and shelters the insects until the adult stage. The insect is considered a serious pest that causes leaf discoloration, severe leaf drop, twig dieback and some tree mortality on some Eucalyptus species. In October 2016, the red gum lerp psyllid was recorded for the first time in Mbizi forest plantation in Tanzania infesting Eucalyptus camaldulensis and different Eucalyptus clones. A study was conducted to determine the susceptibility of Eucalypt germplasm to the insect pest. Results showed that E. camaldulensis was more infested followed by GC 514, GC 167, GC 584, GC 15, GC 785 clones while GC 940 was the least infested. Eucalyptus grandis was not infested. Stakeholders can be able to use the susceptibility grouping of the Eucalyptus germplasm to determine what to plant in areas of red gum lerp psyllid infestation. Similar research work should be carried in all major host tree growing areas to determine susceptibility groups for the areas

Performance of Pinus patula in Areas Invaded by Acacia mearnsii in Sao Hill Forest Plantation, Southern Tanzania

This research article published by Taylor & Francis Online,Problems associated with the invasiveness of exotic tree species such as Acacia mearnsii have increased recently causing vast damage in environment and economy worldwide. Sao Hill Forest Plantation (SHFP) in southern Tanzania which is the potential plantation in East Africa is under Acacia mearnsii invasion which threatens the productivity of the planted species, Pinus patula. This study aimed to gather information on the performance of Pinus patula by comparing areas invaded by Acacia mearnsii with the non-invaded areas in SHFP. The study used a combination of stratified and random sampling techniques to select sample plantation blocks and plots allocation, respectively. Data collected included survival, height, and diameter of Pinus patula in both invaded and non-invaded areas as well as Acacia mearnsii stem counts in invaded areas. The mean basal area, density, and volume of Pinus patula were subjected to paired sample T-test and relationship between the density of Acacia mearnsii and survival of Pinus patula were established by Pearson’s correlation analysis in R software version 3.5.2. Results showed that survival of Pinus patula was decreasing as the density of Acacia mearnsii increased. Also, there was a significant difference in density, basal area and volume of Pinus patula between invaded and non-invaded areas with higher performance being in non-invaded areas. Results suggest that Acacia mearnsii has a negative effect on the performance of Pinus patula in both its growth and survival. This study has generated the information for which among others will help to formulate policies and strategies that will contribute to the effective and sustainable management of forest plantations that should incorporate invasive control measures to avoid the negative performance of desirable tree species