James J. Fox
Australian National University, Canberra, Australia
On Monday, the 13th of January, 2014, the Department of Plant Protection at Indonesia’s prestigious Institute of Agriculture at Bogor (Institut Pertanian Bogor) issued a press release to call attention to the serious looming threat to Java’s rice production for 2014. This threat comes from the enormous build-up of brown planthopper populations identified by intensive field research throughout Java from the middle to the end of the 2013 cropping season. The list of Kabupaten affected by brown planthopper last year reads as a litany of Java’s main rice producing areas: Banyuwangi, Jember, Lamongan, Bojonegoro, Jombang, Kediri, Blitar, Tulungagung in East Java, Pati, Purwodadi, Tegal, Sragen, Boyolali, Klaten, Sukoharjo, Semarang, Banyumas, Cilacap in Central Java, Tasikmalaya, Indramayu, Subang and Karawang. With the outset of the rainy seasons, these populations are forecast to explode in number, spread and become even more devastating.
The brown planthopper (BPH: Nilaparvata lugens Stal) locally known as wereng coklat is a miniscule fast breeding insect that lodges in the stalks of rice plants. It feeds directly on the rice plant; in large numbersand the BPHis capable of sucking the life out of extended fields of rice, causing what is called ‘hopperburn’. The BPH is also a carrier of two destructive rice virus diseases: ragged stunt virus and grassy stunt virus, either of which can be as devastating to a rice crop as the direct feeding by the BPH.
The BPH is a remarkable dimorphic creature. It can produce both fully-winged forms and partially winged forms. The partially winged forms are enormous breeders, each producing up to 350 eggs in roughly two weeks’ time; fully-winged forms, though they produce fewer eggs, are exceptionally mobile and can take off and migrate considerable distances. This combination of local super breeders and equally remarkable migrants makes it exceedingly difficult to predict and control as populations increase.
The BPH has been a scourge to rice production since the introduction of the new rice technologies. The explosion of these pests is due to the overuse of insecticides that destroys the natural enemies of the BPH. Scientists have identified more than 100 natural enemy species that prey on the BPH but they, rather than the BPH, are especially vulnerable to a great variety of general and systemic pesticides. These natural enemies range from hunter spiders that are easily observed to the tiniest of bee-like parasitoids that effectively prey on the BPH eggs.
Scientists from the International Rice Research Institute (IRRI) have done decades of ecological research that show that BPH outbreaks are insecticide induced. The details have been published by Way and Heong (1994), Heong and Schoenly (1998) and Bottrell and Schoenly (2011).
Indonesia has suffered a number of increasingly serious outbreaks of BPH since its uptake of the new rice technologies in 1967. Its first serious infestation of BPH occurred during the 1974/75 planting season and this was followed by a succession of further outbreaks culminating in a particularly severe outbreak in 1985-86. In response, President Soeharto issued a Presidential order (INPRES 3/1986) banning 57 organophosphates pesticides used at the time and eventually removed the pesticide subsidies that drastically reduced insecticide use The BPH problems subsided and for a period of some twenty years thereafter Indonesia enjoyed substantially reduced pesticide use and a steady uninterrupted increase in its rice production—with only limited and localized outbreaks of BPH.
In 2002, in a time of reformation, pesticide policies were changed and the country was opened up to what has become a flood of pesticides, many originating from China. Soon afterwards, as pesticide use increased, the BPH has returned with a vengeance. Based on FAO statistics, between 1990 and 2012, Indonesia’s insecticide imports increased 5824%from US$ 1.19 million to US$ 70.5 million (FAOSTAT 2013)! A build-up of BPH populations that began in 2009 led to the loss of more than 1.96 million tons of rice across Java in 2011. An even more intensive and more wide-spread build-up is now recurring and that is the reason for the urgent press release by the Department of Plant Protection at the Institut Pertanian Bogor.
Major rice producers like Vietnam have implemented strict pesticide distribution programs and strongly encouraged pesticide reduction through mass media programs. Recently the government began introducing ecological engineering programs to conserve natural predators of the BPH. By contrast, Indonesia has seen only an increase in the use of pesticides on rice.
During the New Order, pesticides for rice were limited to a few chemical formulations, mainly organophosphates. Now the situation is vastly different. Many dozens of chemical formulations are available to farmers including varieties of neuro-active insecticides or neonicotinoids, numerous synthetic pyrethroids and even a range of organophosphates that are technically prohibited for rice. These different chemical formulations are sold under thousands of catchy brand names and actively promoted by suppliers’ agents. Sale promotions include the offer of incentives, such as T-shirts, household products, possible free overseas trips and even trips to Mecca. These marketing practices violate the FAO International Code of Conduct for pesticide distribution. Many farmers mix a cocktail of different pesticides and some spray their field up to nine times in a single season. This is in contrast to Vietnam where the average number of insecticide sprays carried out by farmers per crop is less than 2. As a consequence of these insecticide reduction campaigns, Vietnam has not experienced BPH outbreak since 2008..
The IPB press release summarizes field evidence that shows a direct correlation between the number of pesticide applications and the damage to rice fields caused by the BPH in infected areas. Such research results are consistent with the findings from IRRI economists that showed that there is very little productivity gain from insecticide use (Pingali et al 1997). The more farmers spray, reducing natural predators, the greater the extent of hopperburn they suffer.
The IPB scientists estimate that unless something is done immediately to regulate and reduce pesticide use, Java could lose up to 6 million tons of rice in 2014. What is needed therefore is another bold Presidential degree regulating pesticide use in the country and promoting modern biological technologies for the effective control of BPH.
Bottrell and Schoenly 2012. Resurrecting the ghost of green revolutions past: The brown planthopper as a recurring threat to high-yielding rice production in tropical Asia. Journal of Asia-Pacific Entomology 15, 122–140 (pdf)
Heong, K.L. and Schoenly, K.G. 1998. Impact of insecticides on herbivore-natural enemy communities in tropical rice ecosystems. Pp 381-403 ( P. T. Haskell and P. McEwen Eds.) Ecotoxicology: Pesticides and Beneficial Organisms. Chapman and Hall, London. (pdf)
Heong, K.L, Wong, L. and Delos Reyes, J.H. 2013. Addressing planthopper pest outbreak threats to the sustainable development of Asian rice farming and food security: Fixing the insecticide misuse. ADB Sustainable Development Working paper # 27. ADB, Manila, Philippines.
Pingali, P.L., Hossain, M.H. and Gerpacio, R. 1997. Asian rice bowls : the returning crisis? International Rice Research Institute and CABI International.
Way, M.J. and Heong, K.L. 1994. The role of biodiversity in the dynamics and management of insect pests of tropical irrigated rice – A review. Bulletin of Entomological Research, 84, 567-587. (pdf)