An ecological crisis threatens to bring global agriculture to a standstill. Bees, the number one insect pollinator on the planet, are dying at an alarming rate. In parts of China farmers are already forced to pollinate by hand. Many believe that pests,such as the varroa mite, are at the root of this devastation, but recent French studies indicated that these pests struck particularly hard in areas where a new class of insecticides, the so-called neonicotinoids, were being used. Neonicotinoids are revolutionary because they are put inside seeds, and permeate the whole plant because they are water soluble, which is why they are called systemic insecticides. Any insect that feeds on the crop dies. The neonicotinoids may seem ideal insecticides because application rates are much lower than for older, traditionally used insecticides, but, unfortunately, there are catastrophic disadvantages as well.

Any bee or butterfly that collects pollen or nectar from the crop is poisoned. Neonicotinoids bind irreversibly to critical receptors in the central nervous system of insects. The damage is cumulative.The French Comité Scientifique et Technique concluded in 2003 that neonicotinoids were implicated in a mass die-off of the bee population. In 2008, Germany banned seed treatment with neonicotinoids after bee keepers had suffered a severe decline linked to the use of the neonicotinoid insecticide clothianidin in the Baden-Wurttemberg region of Germany.

The second catastrophic disadvantage of neonicotinoids is their potential to leach from soils. Soil acts as a major sink for bulk of the pesticides used in agriculture and public health programs. Pesticides may cause problems when they seep out of storage or are washed out of the soil into waterways and groundwater. The chemicals are then diffused through the environment and may affect marine and bird life. Neonicotinoids are prone to cause such problems because not only are they water soluble and mobile in soil, they are also quite persistent in soil and water. Not surprisingly, the widely used neonicotinoid insecticide imidacloprid has caused major contamination of Dutch surface water since 2004.

Ground and surface water contamination with persistent insecticides that cause irreversible damage to non-target insects is an environmental disaster in the making. The excessive imidacloprid levels noted in surface water of western Dutch provinces with intensive agriculture have already been associated with insect decline and a dramatic decline of common grassland birds. Graham White, an environmental author who keeps bees in the Scottish Borders, recently wrote: “We are witnessing an ecological collapse in all the wildlife that used to live in fields, hedgerows, ponds and streams. All the common species we knew as children are being wiped from the face of the countryside.”

Henk Tennekes
Zutphen, September 2010