Islands Business - Agriculture: SAMOA, FIJI 'GUINEA PIGS' FOR PEST PROJECT

A wasp-moth bio-warfare looks imminent

Dionisia Tabureguci
Samoa and Fiji will be guinea pig countries in a new Integrated Pest Management (IPM) project scheduled to begin this year.

Mike Furlong and Myron Zalucki... scientists from University of Queensland who will lead the IPM project.

The IPM is being put together by the governments of Australia and two Pacific islands with funding from the Australian Centre for International Agricultural Research, ACIAR.

It will be administered through the Secretariat of the Pacific Community (SPC) and is intended to address the problem of diamondback moth (DBM), a major insect pest of Brassica crops, which include vegetables like cabbage, cauliflower, broccoli and turnips.

While there is a lack of data on the economic cost of DBM damage to cabbages produced in the region, it is without doubt that cabbages is the most important introduced leafy vegetables in the Pacific.

There have been previous attempts to control the spread of DBM which is present in some Pacific islands countries, including Samoa, Cook Islands, Papua New Caledonia, Solomon Islands and Fiji.

“Cabbage is important because it is easy to grow and fetches very good price in the market,” says SPC entomologist, Sada Nand Lal.

“In New Caledonia, there are commercial farmers who have become millionaires from cabbage growing.”

This commercial significance makes this IPM project an important one by regional standard.
“IPM is a holistic approach of pest management where we try to employ different methods of pest control in a cropping system to keep the pest level at a point where it is not economically destructive,” says Lal.

The project team cmprises agricultural scientists Dr Mike Furlong and Dr Myron Zalucki from the University of Queensland, Bronwyn Walsh from the Queensland Department of Primary Industries and Forestry, Moti Lal Autur from Fiji, Laisene Samuelu from Samoa, and Lal from SPC.

Furlong, an entomologist specialising in biological control and IPM, will lead the project. He has conducted research on Brassica pests in Queensland since the late 1990s and also in North Korea and China.

The principle behind the Fiji and Samoa project will be similar to those done in the two Asian countries. But the difference would lie in trying to study the pest under a different climatic condition, that of the tropics, says Furlong.

“In order to practise effective IPM, it is essential to fully understand the biology and ecology of target pest insects and their natural enemies,” Furlong explains.

It is more likely that a farmer in Fiji or Samoa would spray his entire crop after finding one diamondback moth on a cabbage leaf, rather than just picking it up and squashing it.

Using chemicals in this case is both expensive because it is needless and wasteful because one moth does not necessarily mean the entire field is teeming with destructive insects.

“I think people in the Pacific are using a lot of pesticides,” says Lal. “These days, if you go to a farmer who has a pest problem, the first question he asks is what pesticide can he use and where can he get it from?

“That tells us that there is a lot of usage and misuse of pesticides. So hopefully through this IPM programme, we can develop the view that pesticides should only be used when necessary.”

But as simple as it may sound, running an IPM requires much study and observation of the target pest and how it functions in its environment and there is every effort to use the native natural enemies.

In the case of diamondback moth, Furlong says there are many natural enemies, such as certain species of spiders, beetles and bugs.

The most important ones are the parasitic wasps, which are already present in Samoa and Fiji.

“Previous initiatives have released several species of parasitic wasps as biological control agents for the control of diamondback moth in the region,” Furlong explains.

“We will determine which of these (wasps) are currently established in the major vegetable production regions of both Fiji and Samoa. Once we know which species are present, we will determine their impact on the local diamondback moth population.”

These wasps do damage by laying eggs inside the moths at caterpillar stage. They eventually kill their host and the adult wasps emerge to kill the next generation of the pest.

“Several species of these wasps have resulted in effective biological control of diamondback moth as part of IPM in many different countries,” says Furlong.

After this initial scientific stage, the team will hold workshops in Fiji and Samoa where stakeholders-farmers, local and regional agricultural extension officers and scientists, pesticide sellers and the interested members of the public-will be introduced to the project, Furlong says.

“Demonstration trials at research stations in Samoa and Fiji will illustrate the key principles of IPM and compares its effectiveness against current standard practise,” he adds.

“In addition to the scientific/research activities, a key focus of the project is the effective extension of the project information to stakeholders. It is to this end that the project will develop farmer field schools (FFS) in Fiji and Samoa.

“FFS have been extremely effective in many agricultural systems in Asia. The project aims to firmly establish FFS as an effective mechanism of extension with Fiji and Samoa,” says Furlong.