Weaver ants

The use of arboreal ants in Vietnamese and Indonesian fruit orchards as an alternative to pesticides

In Southeast Asia, the livelihood of millions of smallholders depends on fruit and nut grown in relatively undisturbed perennial agro-ecosystems that offer opportunities for biodiversity conservation. Orchards, which are traditionally small-scale and diversified, often function as refugia for wildlife. But these ecosystems are increasingly replaced with monocultural tree cropping systems dependent on pesticide use which harm public health and natural resources. Agrochemical companies are now targeting high value fruit crops for their sales of the most toxic group of pesticides: insecticides.

Viable alternative practices could reverse this trend however. Barzman (1996, 2000) and Van Mele et al (2002) showed that some Vietnamese farmers successfully use traditional practices that rely on biodiversity rather than pesticides. The key element in this ecological approach to fruit farming is the use of Oecophylla smaragdina, a tree-dwelling ant. The ant preys on a variety of pests while a host of other natural enemies regulate other noxious species. By providing an ant-friendly habitat, farmers also create an environment favorable to wild fauna and flora. By adapting this Vietnamese practice to local conditions, eco-innovating fruit producers and agricultural researchers and advisors in other parts of Southeast Asia could develop alternative practices.

With this idea in mind and with the support of the Conservation Food and Health Foundation, this program is building a partnership between Can Tho University (Vietnam), the Vietnam Gardeners' Association VACVINA (NGO), Bogor Agricultural University (Indonesia), the Southeast Asian Regional Centre for Tropical Biology, and CABI-Bioscience (UK). The partnership's activities include:

1. Documenting traditional knowledge on tree-ant use in Indonesia.

2. Testing the viability of an ant-based pest control approach in perennial cropping systems in Indonesia.

3. Translating and publishing "Ants as Friends" (Van Mele & Cuc, 2003), a simple yet scientifically-sound book on the use of ants in tree crops, both in Vietnamese and Bahasa Indonesia.

4. Developing a training curriculum in Vietnam for the national agricultural extension system.

5. Providing students from across Southeast Asia with training on the use of beneficial ants at the Southeast Asian Regional Centre for Tropical Biology.

The potential environmental, public health and economic impact of this program is significant. Since the geographic distribution of this ant covers all of tropical Asia, the entire region could benefit from such environmentally-friendly eco-innovations.

• Barzman, M.S., N.J. Mills & N.T.T. Cuc, 1996 . Traditional knowledge and rationale for weaver ant husbandry in the Mekong Delta of Vietnam., Agriculture and Human Values 13(4): 2-9.
• Barzman, M.S, 2000. Weaver ants in orchards and groves. In Natural Crop Protection in the Tropics; G. Stoll ed., pp. 99-100.
• Van Mele, P., N.T.T. Cuc, & A. Van Huis, 2002 . Direct and indirect influences of weaver ant Oecophylla smaragdina husbandry on citrus farmers' pest perceptions and management practices. International Journal of Pest Management, 48 (3), 225-232.
• Van Mele, P. & N.T.T. Cuc, 2003. Ants as Friends: Improving your Tree Crops with Weaver Ants. CABI Bioscience¸ pp. 67. ISBN 958-97218-2-6.
• Van Mele Paul, T.V. Hai, O. Thas and A. Van Huis, 2002. Influence of pesticide information sources on citrus farmers' knowledge, perception and practices in pest management, Mekong Delta, Vietnam. International Journal of Pest Management, 48 (2), 169-177.
• Van Mele Paul and J. Van Lenteren, 2002. Habitat manipulation for improved control of citrus leafminer and mite pests in a mixed orchard-ricefield landscape, Mekong Delta, Vietnam. Agriculture, Ecosystems & Environment, 88 (1), p. 35-48.
• Van Mele Paul and V.T. Truyen, 2002. Observations and farmer experimentation with predatory ants. LEISA, 18(1), pp. 28-29.
• Van Mele Paul, Vo Mai, Ho Van Chien and Nguyen Thi Thu Cuc (eds.), 2001. Weaver Ants: A Golden Opportunity. Proceedings of Citrus Farmer Workshop, February 2001, Tien Giang, Vietnam. CABI Bioscience, pp. 25.
• Cuc Nguyen Thi Thu, Vo Mai, Ho Van Chien and Paul Van Mele, 2005 . Discovery Learning: A Manual to Promote Better Pest Management in Tree Crops, Conservation, Food and Health Foundation, 14 p.

For full text pdf versions of these articles, please contact the authors, Paul Van Mele or Marco Barzman

Also see the articles below for more detailed information.

Contact: Marco Barzman at marco.barzman@eco-innovation.net