The recent locust upsurge in West Africa presented a long-awaited opportunity to demonstrate the efficacy of a new environmentally friendly product for locust control1. Now, just a few months later scientists are delighted to report that Green Muscle®, has been successfully tested against the desert locust (Schistocerca gregaria) under large-scale field conditions. The field application was organized jointly by the plant protection authorities of Algeria and the Food and Agriculture Organisation near El Oued in eastern Algeria where Green Muscle® was sprayed on more than 1400 hectares of land infested by desert locust nymphs.
Green Muscle® is a substance composed of the spores of the naturally occurring fungus Metarhizium anisopliae formulated in mineral oils. The biopesticide is not toxic to humans and kills only locusts and grasshoppers and a very limited number of other insects; it has no other environmental side-effects.
The trial in Algeria was conducted under optimal temperatures that favoured the development of the fungus. Just four days after the application of Green Muscle® the locusts were seen to become weakened and started moving slowly making them highly susceptible to predation by birds, lizards and ants. Under these ideal conditions, control was achieved in seven days.
While most conventional pesticides kill locusts immediately, Green Muscle® may need up to three weeks to grow within the body of the insect and finally kill it. The length of the incubation period depends on the environmental temperature; the fungus grows well between 15 and 35º C. In the northern African and Sahelian countries that are most affected by desert locust infestations, this temperature range prevails during parts of the winter and the rainy season when locusts breed. More field tests under less favourable conditions are required to explore the potential and limitations of the product.
Green Muscle® is not expected to entirely replace synthetic pesticides. Conventional, rapidly acting products will continue to be used to protect crops from imminent locust attacks by hoppers and swarms. Nevertheless, based on the results of the application in Algeria, Green Muscle can now be promoted for wider use, specifically in preventive control programmes. Where used, Green Muscle® will result in significant environmental benefits and reduced operator exposure to potentially toxic chemicals. The testing will continue to fine-tune our knowledge about its efficacy, and a training programme is in
preparation.
1. Locust upsurge allows environmentally safe control to be tested, Pesticide News 67, p12, March 2005Nina Jenkins – CABI Bioscience, Bakeham Lane, Surrey, TW20 9TY, www.cabi-bioscience.org/html/biocontrol.htmn.jenkins@imperial.ac.uk