Jiaan Cheng, Zhejiang University, Hangzhou, PR China, and
K.L. Heong, International Rice Research Institute, Los Baños, Philippines
Planthoppers are r -strategists with high capacities to exploit ephemeral habitats, like rice. In the 1st Green Revolution, rice intensification programs, such as Masaganna 99 in the Philippines and BIMAS in Indonesia, packaged with fertilizers and insecticides were threatened by widespread outbreaks of the brown planthopper (BPH). In China BPH has been a major pest problem since the 1960s causing an annual loss of about a million tons of paddy as insecticide use intensified. In some years losses could reach > 2.5 million tons. Today despite the millions spent in research, developing resistant varieties and training farmers in IPM techniques, rice production in Asia is again threatened by planthoppers. This time it is not just BPH, there are now two other species of importance, the white back planthopper (WBPH) and the small brown planthopper (sBPH). In addition, the WBPH is transmitting a new virus disease which is spreading rapidly. The outbreaks in the last 5 years had probably caused one of the biggest economic losses and hardship to thousands of farmers. Why are we still getting planthopper problems despite the 32 resistant genes plant breeders have identified, the hundreds of peer reviewed papers published and the millions of farmers trained in IPM? Numerous studies have shown that planthoppers are secondary pests induced by insecticide use (Read: Review Heong & Schoenly) but yet farmers continue to apply prophylactic insecticide sprays routinely. In the early crop stages farmers seem to target the leaf feeding insects (Heong & Escalada 1997) with pyrethroids and organophosphates that are particularly toxic to natural enemies and thus destroy the ecosystem services that regulate pests. In the last 10 years rice farmers’ insecticide use had increased and insecticide imports in many countries escalated.
The pesticide industry has penetrated into the rural grassroots making pesticides readily available. In many countries, pesticide regulatory systems have broken down and are facilitating the free marketing of these deadly poisons. A single active ingredient can be sold in > 500 trade names in combination with other active ingredients, more for profit purposes. Pesticide “kiosks” operate in villages and operators’ licenses are easily obtainable. Most of these kiosks have become by default pest control advisors because extension agents, too few in numbers, hardly visit farmers in the remote villages. Some countries continue to subsidize pesticide inputs and authorities are often quick to release emergency budgets to provide pesticides free. Why are the research results not communicated and used by agricultural authorities and farmers? Or perhaps there are other root causes beyond the realms of scientific research findings and utility?
Researchers and extension personnel generally adopt procedural rationality attitudes and often would only do research or present results but fail to focus attention on the potential impacts of the results on farmers. The inconvenient truth (after Al Gore) continues to be masked or corrupted by the culture, structure and the expected “norm behavior” (Read: Procedural rationality). Over the last 5 to 10 years, there has been general relaxing of pesticide regulations in many countries and this has resulted in proliferation of products, labels, mixtures, packaging, advertising and marketing often “mis selling” to unsuspecting farmers. Since farmers tend to rely on local pesticide kiosks for advice and are confused with the multiple names, they generally do not know that many of the insecticides they use are in fact BPH resurgence causing (Read: Farmers’ insecticide selections). In fact in many cases kiosk owners would advice farmers to use resurgence causing pyrethroids “because these chemicals kill the eggs”.
With weak regulations, mis selling of products has become widespread resulting in rampant misuses and overuses that make farms vulnerable to planthopper invasions (Read: Spraying increases vulnerability). The root cause of the increased hopper outbreaks appears to be the severe weakening of the pesticide regulatory systems which need to be reformed if planthopper outbreaks are to be controlled and farmers falling victims to be avoided. Without an adequate pesticide regulatory system that will prevent abuses, any sustainable pest management tools we introduce, like IPM, ecological engineering, biological control and varieties, will be wiped out by the “pesticide tsunami” (Read: Yin and Yang of pest management/) and farmers will continue to fall victims to pesticide abuses. The “pesticide tsunami” is driven by national objectives to ensure adequate food supplies and thus adopt policies to increase inputs, such as fertilizers and pesticides. In China, the government continues to promote the pesticide first policy (Widawsky et al 1998). This may be based on the notion that pesticides will increase yields. However in the case of insecticides this notion is hardly true. Farm surveys showed that yields are either not related to insecticide inputs or in many cases negatively related (Read: Do insecticides increase yields). Similarly farmers respond to increase in rice prices by spraying more because of loss aversion attitudes and pesticide availability (Read: Determinants of insecticide use).
The “pesticide tsunami” not only prevents the adoption of more sustainable pest management options, it also wipes out the ecosystem services (MA 2005) provided by the diversity of predators and parasitoids making fields vulnerable to invading planthopper adults (Read: Insecticides make fields vulnerable). The second green revolution looks destined to follow the fate of the first with regards to pest management unless reforms in pesticide regulatory and marketing systems, policies, incentive systems and shifts in pest management paradigms occur.
Heong, K.L. and Escalada, M.M. 1997. (Eds). Pest management of rice farmers in Asia. IRRI, Los Baños, Philippines.
MA (Millennium Ecosystem Assessment). 2005. Ecosystems and human well-being: biodiversity synthesis. Washington, D.C. (USA): World Resources Institute.
Widawsky D, Rozelle S, Jin S and Huang J. 1998. Pesticide productivity, host-plant resistance and productivity in China. Agric. Econ. 19:203-217.