Double Agent

Helicoverpa armigera, commonly known as the cotton bollworm or legume pod borer, causes annual crop damage estimated at as much as US$ 2 billion globally. This does not include an additional cost of US$500 million spent on insecticides for its management. Interestingly, Helicoverpa larvae also provide a priceless environmental service, as they can be used to produce a biopesticide to protect crops from Helicoverpa itself.

A Helicoverpa armigera larva (caterpillar) bores its way into a chickpea pod.

The International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) has added a modern twist to a traditional technology. It has also succeeded in establishing biopesticide production units in nearly 100 villages in India and Nepal in collaboration with national agricultural research and extension systems and nongovernmental organizations, through a project funded by the World Bank. This project proposal won one of the World Bank's Development Marketplace Award for 2005.

Farmers in India and Nepal traditionally shake crop plants to dislodge Helicoverpa larvae. Using these larvae for the multiplication of the nucleo polyhedrosis virus (NPV), a biopesticide that kills Helicoverpa, is the modern twist that ICRISAT provided. NPV production begins with collecting the larvae and feeding them with an NPV-laced diet until the infected larvae die. The NPV biopesticide is extracted from the dead larvae and can be sprayed on crops to manage Helicoverpa attacks.

The high impact enjoyed by the biopesticide, augmented with other ecofriendly activities, in 96 villages in India and Nepal over the past 2 years, has allowed farmers to reduce their spraying of chemical pesticides by 65% in cotton, 24% in pigeonpea and 21% in chickpea, thereby reducing input costs and protecting the environment and crop-friendly insects.

Through the biopesticide production project in India and Nepal, says Dr. William Dar, director general of ICRISAT, the institute and its partners have placed production of an effective biopesticide in the hands of villagers. This enables them to become self-sufficient in meeting their needs for the biopesticide.

Dr. G.V. Ranga Rao, an ICRISAT scientist working on integrated pest management, observes that the project has not only provided farmers with an alternative to chemical pesticides to deal with the Helicoverpa problem, but also enabled them to start biopesticide production in their villages.

The World Bank Marketplace Award enhanced the scope of the project by funding the establishment of decentralized biopesticide production units in 76 villages in India and 20 in Nepal. In addition to establishing the village-level biopesticide units, ICRISAT and its partners trained 201 researchers and 983 farmers in India and Nepal on techniques of NPV production at the village level and on integrated pest management.

For further information, contact Dr. G.V. Ranga Rao at g.rangarao@cgiar.org.