Locust control update

During the growing season of 1995 further field trials using the fungus Metarhizium flavoriride to control locusts and grasshoppers have been carried out in several regions of Africa. (See Spore 55 p 1). The international collaborative locust and grasshopper biological control programme (LUBILOSA) worked with the Niger Service de Protection des Vegetaux to spray some 50-hectare plots of grassland in Eastern Niger which were grasshopper infested. Three weeks after spraying, the pest population had declined by over 70% and was still decreasing. There was also evidence that the pathogen from the initial spraying multiplies in the insects which results in further spread of the infection. Researchers from the International Institute of Tropical Agriculture (IITA) also tested Metarhizium in Mali and Niger to treat bands of grasshoppers (Zonocerus variegatus) in the bush alongside croplands to prevent them entering the crop. Pests began to die eight days after spraying and continued to do so for the next ten days. Populations continued to decline and there was no subsequent recovery later in the season. In Mauritania, LUBILOSA collaborated with the crop protection authorities and also the German aid agency, GTZ to treat the desert locust Schistocerca gregaria. Whilst in South Africa in separate trials, LUBILOSA and collaborators used aerial applications of Metarhizium formulations against the brown locust populations. Farmers have been encouraged not only by the level of effectiveness of the fungal biocontrol but also that use of the fungus is safer and cheaper than chemicals. CAB Intenational Wallingford Oxon OX10 8DE UK IITA BP 08 0932 Cotonou BENIN