KOMAZA is excited to announce a four-year research partnership with the Kenya Forestry Research Institute (KEFRI). We are participating in KEFRI’s nationwide entomology research project to better understand the eucalyptus pest blue gum chalcid (BGC). The project will test mitigation strategies in order to limit the ravaging effects the chalcid wasp has on eucalyptus plantations.
The economic impacts of BGC
Blue gum chalcid, Leptocybe invasa (Hymenoptera: Eulophidae) is a pest that has invaded eucalyptus, stunting tree growth and in some cases causing broad mortality across woodlots. Given that eucalyptus is a significant part of Kenya’s forest cover, with over 90 species present in Kenya, the tree is a vital contributor to the national supply of wood. Some estimate that it contributes about KSH 1 billion to the economy each year. It is critical to protect farmers from the blue gum chalcid, as widespread mortality would cause significant economic losses.
The spread of BGC
The pest originates in Australia and came to Kenya in 2002 by way of Israel, migrating down through northern Africa. It is now causing mortality in woodlots in Kenya, Uganda, and Tanzania – and is expected to continue marching toward South Africa. Within Kenya, the chalcid wasp has affected trees in Nyanza, Western, Central Rift Valley, Eastern, and Coast Provinces. Introduced to the Coast in 2003, the pest spread across most Coastal districts by 2009. KEFRI has been monitoring the spread of BGC attacks along the Coast since 2005.
Responses to BGC
Effectively managing BGC is a challenge. Widespread use of chemical controls (such as systemic insecticide Methomyl or Methomex 90SP) is both environmentally unsound and economically unviable. Species diversification is one effective way to reduce the spread and severity of BGC attacks, a step that KOMAZA is embarking on with the introduction of the indigenous Melia volkensii as part of KOMAZA’s evolving farmer package (research continues into other commercially viable tree species).
One of the most effective pest management strategies is a Classical Biological Control (CBC) strategy, which involves the introduction of a biological control agent that is a natural enemy of blue gum chalcid. KEFRI has identified two parasitoids, Quardivasticus mendeli (QM) and Selitrichody koycevv (SK) as potential biological control agents which together have been effectively used against BGC in Israel and elsewhere in East Africa. It is these two parasitoids that KEFRI is evaluating in this “biological control” study.
Trial design details
KEFRI has applied for – and been approved for – governmental permits to import Quardivasticus mendeli (QM) and Selitrichody koycevv (SK) from Israel, first to conduct safety tests and then to be introduced into BGC-infested woodlots in Kenya. These parasitoids have been screened against a number of indigenous trees and plant species similar to eucalyptus to ensure that they will not have unintended effects on the ecosystem.
The trial design involves three plots of 500 eucalyptus trees each, each plot planted with different types of eucalyptus (E. urophylla, GC167, and GC10). KOMAZA’s plots are part of dozens of test plots in three provinces across the country (with at least three test plots per region in Western, Nyanza, and Coast provinces), which will be both pre- and post-release monitoring sites for several years after woodlot planting.
We will collect data on the incidence and severity of blue gum chalcid on the three trial plots. Then, the two parasitoids will be released onto the woodlots and data collection will continue to see whether the incidence and severity of BGC attacks decrease due to the natural predators. Specifically, the research will determine:
- The population and damage dynamics of BGC in the Coastal region
- The most effective method of the biological control agent’s release by assessing its establishment and dispersal rates
- The impact of the parasitoids on reducing the impact incidence and severity of BGC
KOMAZA role in the trial
KOMAZA’s role is to plant and maintain three research plots of eucalyptus, each plot containing a different variety of the tree. KOMAZA will gather data on blue gum chalcid outbreaks. Over time, KOMAZA will help KEFRI analyze the data from various research plots across Kenya to determine the effectiveness of the parasitoids in stemming the spread of BGC. As well, KEFRI hypothesizes that E. urophylla, unlike other types of eucalyptus, is not a host of BCG, and can thus act as a natural buffer to the spread of BGC; therefore the incidence of BGC on E. urophylla will be comparatively analyzed to see if this hypothesis bears out with the data.
KEFRI’s role in the trial
KEFRI’s role is to lead the research trial, which involves:
- Providing technical expertise and necessary equipment
- Conducting site visits several times a year and as necessary if any problems arise
- Analyzing data as part of larger study
- Publishing the summary article in a scientific journal
The research will be conducted over the next four years, and the results of which are expected to be communicated in an academic journal.
Our experimental farm
The joint research is just one trial that KOMAZA is conducting on its experimental farm – the “X-Farm.” KOMAZA is committed to conducting best practice research about our crops – to ensure that they grow as successfully as possible while establishing a net positive environmental impact. We make operational improvements based on our research findings which help us better serve our farmers.