Awhere-ACT: predicting pest outbreaks in Africa

Awhere-ACT, a user-friendly geographical information systems (GIS) tool, is helping farmers and scientists in Africa to combat pests such as stem borers and the cassava green mite.

Scientists in developing countries are becoming increasingly aware of the value of spatial information for assessing and predicting the distribution of insect pests. In this process, geographical information systems (GIS) can play a key role in the management, visualization and analysis of geographical data in digital format.

So far, however, GIS have remained largely in the domain of experts, with access often restricted by factors such as cost, complexity and the availability of data, particularly in developing countries.

To rectify this situation, a team of software developers from Mud Springs Geographers, Inc., in collaboration with the International Maize and Wheat Improvement Centre (CIMMYT), developed the Awhere Almanac Characterization Tool (ACT), a stand-alone package that is well suited to the needs of agricultural researchers and decision makers in developing countries. Awhere-ACT is unique in that it integrates GIS tools with extensive databases (on climate, land use, elevation, etc.) relevant to agriculture. It is also user-friendly – with only a few days’ training, users can easily generate maps showing, for example, zones with similar climatic conditions in a particular season. The package is available free to users in developing countries.

Scientists involved with a number of insect pest management programmes in Africa are now benefiting from the facilities provided by Awhere-ACT, as the following examples demonstrate.

Predicting the spread of stem borers

Maize is one of the most important staple food crops in sub-Saharan Africa, but farm productivity is limited by a variety of insect pests, in particular the stem borer beetle. There are several native species of stem borer in the African maize belt, but the exotic Chilo partellus is by far the most devastating. Introduced from Asia in the early 20th century, Chilo has spread to all countries in East and Southern Africa, and is still extending its range.

The Biological Control of Cereal Stem Borers project of the Nairobi-based International Centre for Insect Physiology and Ecology (ICIPE) is following a classical biological control approach, whereby natural predators associated with Chilo in Asia are being introduced into Africa. Using Awhere-ACT, researchers at ICIPE first determine which climatic factors, such as rainfall and temperature, favour the spread of the borer in Asia. They then identify those areas in Africa where the climate conditions are similar, allowing them to predict those that are likely to be at risk of Chilo invasions in Africa, and to recommend where to introduce natural predators.

Identifying fungus release sites to control the cassava green mite

The cassava green mite, Monony-chellus tanajoa, is a major pest that affects cassava in many parts of Africa. Controlling this mite has been the focus of a long-running biological control programme of the International Institute of Tropical Agriculture (IITA). In Brazil, the mite’s country of origin, its spread is effectively restricted by a pathogenic fungus, Neozygites tanajoae. IITA has recently introduced the fungus as a control agent in Benin, where it has become established in some areas. Based on this success, researchers at the Kenyan Agricultural Research Institute (KARI) and IITA are now using Awhere-ACT to identify areas in Kenya with agro-meteorological characteristics similar to those in Brazil and Benin where Neozygites has been successful, so that they can specify the most effective release sites.

In both of these examples, the application of appropriate GIS tools and databases is helping African scientists to make better decisions regarding where to target their pest control interventions, thereby increasing the efficiency of the research process and contributing to the efforts to ensure food security.

For further information on Awhere-ACT, visit Mudsprings.

Rose W. Irungu is a researcher at ICIPE.
Dave Hodson is Head of GIS at CIMMYT.
Eric I. Muchugu is a GIS scientist at ICIPE.

This article is based on contributions from Awhere-ACT users at CIMMYT and ICIPE. Funding for Awhere-ACT in Africa has been provided by USAID.