K.L. Heong, International Rice Research Institute, Los Baños, Philippines and
Maarten Bijleveld van Lexmond, Chair, ICUN Task Force on Systemic Pesticides, Switzerland
Bees provide valuable pollination services as well as produce honey and are seriously threatened by the large scale use of neonicotinoid insecticides.
Neonicotinoids are relatively new insecticides being strongly marketed in rice for planthopper control. These include insecticides with active ingredients, imidacloprid, thiamethoxan and clothianidin. In Asia these insecticides are sold either singly or in mixtures marketed in hundreds of trade names. Recently evidence has mounted further that these three insecticides are strongly linked to colony losses and bee disorders and subsequently to loss of pollination services. Two recent publications in SCIENCE and NATURE and about 50 other studies published in specialist scientific journals over the past 2 years all show a consistent pattern of high risk to bees in normal use of neonicotinoids. These chemicals are not only mass killers of bees during spraying and uses as seed dressing, but long term exposure to residue levels in pollen and nectar disrupt the colony and are major factors in weakening bee colonies. SCIENCE report. The European Food Safety Authority (EFSA) has identified risks to bees even if the products were used in seed treatment especially in corn and oil seed rape. For all other seed treatment applications and granular applications, data are still lacking to establish conclusively if it is safe enough while there are indications that it is potentially of high risk. France banned seed coating of sunflowers in 1999 and for maize in 2004 and banned thiamethoxam for oil seed rape. Italy has completely banned all seed coating with imidacloprid, thiamethoxam, clothianidin and fipronil from 2008. Slovenia did the same in 2011. The European Parliament in 2012 published “Existing Scientific Evidence of the Effects of Neonicotinoid Pesticides on Bees” and concluded that the risk to bees of normal applications of neonicotinoids is not acceptable and current European risk assessment methods by authorities are seriously flawed. In January 2013 the European Commission announced that steps are being taken to phase out these 3 neonicotinoids for all applications that pose high risks to bees ((http://www.reuters.com/article/2013/01/25/us-eu-pesticides-idUSBRE90O0WM20130125). The European Environmental Agency published a report with a chapter on neonicotinoids and bees (chapter 16 of http://www.eea.europa.eu/publications/late-lessons-2 ) pointing out that the scientific facts about the risks to neonicotinoids to bees have been ignored by policy makers for more than 10 years.
The threats of the neonicotinoids on bees, ecosystems and humans in Japan are also documented. Meanwhile Syngenta and Bayer remain convinced that these pesticides are safe and effective and criticized the EFSA report (http://www.nature.com/news/row-over-reports-on-bee-bothering-insecticides-1.12234).
These insecticides have been used intensively in China and rice planthoppers have grown immune acquiring resistance of up more than 500 folds (See Matsumura et al 2009 (Read: Current status of insecticide resistance in rice planthoppers). Recent resistance monitoring research has also recorded resistance developing in Thailand and Vietnam. China is the world’s largest producer of imidacloprid but with the recent government’s restricting its use (especially to be phased out of rice), manufacturers are seeking export markets, particularly in ASEAN countries. Imidacloprid had fallen from grace, “from hero to zero” because of massive misuse practices.
The three neonicotinoid insecticides are widely distributed in ASEAN from Indonesia, Vietnam to Thailand and even in Myanmar. Recently the Philippines launched a product with thiamethoxan as one of the components, popularly promoted in Indonesia. The properties of thiamethoxan are similar to that of imidacloprid and planthoppers have shown to rapidly develop cross resistance (see Matsumura et al 2009).
The rice ecosystem is richly endowed with a huge biodiversity of hymenopteran parasitoids (e.g parasitic wasps) that are being threatened by the 3 insecticides. Hymenopteran parasitoids are extremely important players contributing to pest regulatory services. Parasitoids are generally smaller and have to move about to hunt for prey and thus are more vulnerable to these insecticides. In ecological engineering fields where bunds were populated with nectar rich flowers to provide resources to parasitoids, planthopper populations were suppressed. These 3 insecticides are likely to impair the pest regulatory services provided by the parasitoids.
Several ASEAN countries are now actively promoting ecological engineering to reduce vulnerability of intensive rice cultivations to planthopper outbreaks. There is thus need for research, private sector and government policy makers in ASEAN countries to dialogue and initiate a process to regulate and restrict their use especially in agricultural areas dependent on parasitoids and in areas of honey and fruit production to avoid potential detrimental effects on agriculture. With these pesticides being banned or restricted in Europe and China, the main manufacturers, and pesticides being sold as FMCGs (fast moving consumer goods), the spread of use and misuse of these pesticides will be very fast and threatening to agriculture. Pollination and biological control ecosystem services are agriculture’s most important regulatory services. IRRI working with German universities recently started a landscape study of these services in a project called LEGATO that will provide valuable research information on the threats to pollination and biological control.
The egg parasitoid in action attacking planthopper eggs captured on video is available.
The three insecticides are available in the market either singly or in cocktails under hundreds of trade names. Some common ones include Actara, Agite, Alika, Adage, Centric, Cruiser, Flagship, Meridian, Platinum, Vifone, Virtako, Gaucho, Admire, Merit, Poncho, Votivo, Confidor, Solomon, Provado. Many local names are given to mixtures using these three insecticides and many more product names in Chinese, Thai, Vietnamese and Indonesian.