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A very important shift may be occurring in our understanding of pesticides: risk may increase over time, rendering even very small amounts of pesticides such as some nicotine-based neonicotinoids much more toxic than previously realized. Dutch researcher Dr. Henk Tennekes, with Dr. Francisco Sanchez-Bayo of Australia, have shown this in a new article in the Journal of Environmental & Analytical Toxicology: "Time-Dependent Toxicity of Neonicotinoids and Other Toxicants: Implications for a New Approach to Risk Assessment" that is an open-access research article downloadable with the link http://www.omicsonline.org/2161-0525/2161-0525-S4-001.pdf. Dr. Tennekes summarizes his deep concerns: "The article reviews a paradigm shift in the science of toxicology. The dose : response characteristics of neonicotinoid insecticides and certain metallic compounds turn out to be identical to those of genotoxic carcinogens, the most dangerous substances we know. Such poisons can have detrimental effects at any concentration level. Current pesticide risk assessment procedures are flawed and have failed to protect the environment. Regulators so far appear to be unwilling to accept this inconvenient truth. The powerful pesticide lobby does not want to face up to it either because the adoption of new risk assessment procedures would almost certainly lead to a ban on the money-spinning neonicotinoids, which are registered in more than 100 countries worldwide for use on more than 140 crops. They also have widespread applications in non-crop, including nursery, landscape, forestry, pest control and veterinary applications. Neonicotinoids are persistent and mobile in the soil and leach to ground water, and runoff to surface waters. Insects are now quietly but rapidly disappearing all over the globe, which will ultimately lead to collapse of the ecosystem and life as we know it. This is an ecological disaster that will affect us all, and that must be stopped."

We used LC/MS-MS to analyze samples of honey bees, pollen stored in the hive and several potential exposure routes associated with plantings of neonicotinoid treated maize. Our results demonstrate that bees are exposed to these compounds and several other agricultural pesticides in several ways throughout the foraging period. During spring, extremely high levels of clothianidin and thiamethoxam were found in planter exhaust material produced during the planting of treated maize seed. We also found neonicotinoids in the soil of each field we sampled, including unplanted fields. Plants visited by foraging bees (dandelions) growing near these fields were found to contain neonicotinoids as well. This indicates deposition of neonicotinoids on the flowers, uptake by the root system, or both. Dead bees collected near hive entrances during the spring sampling period were found to contain clothianidin as well, although whether exposure was oral (consuming pollen) or by contact (soil/planter dust) is unclear. We also detected the insecticide clothianidin in pollen collected by bees and stored in the hive. When maize plants in our field reached anthesis, maize pollen from treated seed was found to contain clothianidin and other pesticides; and honey bees in our study readily collected maize pollen. These findings clarify some of the mechanisms by which honey bees may be exposed to agricultural pesticides throughout the growing season. These results have implications for a wide range of largescale annual cropping systems that utilize neonicotinoid seed treatments.

Invertebrates are an essential food source for most farmland birds. Dvac suction sampling was used to determine the abundance, biomass and community composition of those invertebrate groups considered important in the diet of farmland birds for the commonest arable crops. Approximately 40 fields were sampled at the edge and mid-field over 2 years in three different locations in England. In cereals, the fauna was primarily comprised of Araneae (10%), Coleoptera (30%) and Hemiptera (58%), whereas the oilseed rape fauna was dominated by Coleoptera (65%) and peas and potatoes by Hemiptera (89%). Beans contained a high proportion of Coleoptera (39%) and Hemiptera (49%). Aphididae were the most abundant family (20–86% of total), although in oilseed rape and beans, Chrysomelidae, Curculionidae and Nitidulidae formed ca 20% of the fauna. Aphids only formed a small proportion (7%) of the total biomass, except in peas (32%). Instead, Araneae, Carabidae, Heteroptera, Homoptera and Tipulidae formed much larger and more equal proportions. The highest abundance and biomass of invertebrates were recorded in cereals and least in potatoes. The Grey Partridge chick-food index in all crops was only a half or less of the level required to ensure that chick survival is sufficient to maintain numbers of this red-listed species.

Pesticides have major indirect effects on birds via the killing of both invertebrates important for food and also agricultural weeds which provide seed resources and also cover for invertebrates. Several pieces of evidence support the negative relationship between insecticide spraying and vital rates of farmland bird populations. Probably the best example comes from a fully replicated study of the grey partridge (Perdix perdix L.). This study showed that pesticide spraying affected the invertebrate food of partridge chicks, which was correlated with chick survival, and was the main cause of population decline. More recent examples come from another farmland bird specialist, the yellowhammer (Emberiza citrinella). A study showed that arable fields sprayed during the summer were used less frequently than fields not sprayed during the summer by adult yellowhammers foraging for food for their young. The availability of arthropods was depressed up to 20 days after an insecticide spraying event and this negatively affected yellowhammer chick survival. Both herbicide spraying and fungicide spraying have also been shown to be negatively correlated with invertebrate populations and weed populations and so these are also likely to negatively affect farmland bird populations.

Birds are widespread, readily observed, feed at many levels of the food web, and are responsive to environmental change, making them good indicators of ecosystem health. Globally, over 150 species of birds have been lost since the 16th century and one in eight is currently threatened with extinction. Over the past 20 years, the status of the world’s birds has deteriorated, with more species moving closer to extinction. Of particular concern are declines in formerly common species. The last 20 years have witnessed a steady decline of bird species in terrestrial, freshwater, and marine ecosystems. Between 1988 and 2008, the status of 225 bird species was elevated to a higher level of risk.

Conservation association Burung Indonesia reports that 122 Indonesian bird species included on the International Union for Conservation of Nature (IUCN) red list could go extinct; 18 bird species in Indonesia are in critical condition, 31 species are endangered and 73 species are categorized as vulnerable. Burung Indonesia program manager Ria Saryanthi said that Indonesia had the highest number of birds that could go extinct. Indonesia has a tremendously diverse variety of bird species. According to Ria, 1,594 bird species from a total 10,000 known birds in the world are endemic to Indonesia. This ranks Indonesia fifth in terms of nations with the greatest diversity of bird species.

Imidacloprid is the first highly effective insecticide whose mode of action has been found to derive from almost complete and virtually irreversible blockage of postsynaptic nicotinic acetylcholine receptors (nAChRs) in the central nervous system of insects. Imidacloprid mimics the action of acetylcholine, but unlike acetylcholine, imidacloprid is not deactivated by acetylcholinesterase and thus persistently activates nAChRs. Chronic exposure of insects to imidacloprid therefore leads to cumulative and virtually irreversible blockage of nAChRs in their central nervous system, which play roles in many cognitive processes. A honey bee during a foraging flight must learn and recall many complex visual patterns. These cognitive functions may be perturbed when nAChRs, necessary for the formation of longterm memory and involved in acquisition and retrieval processes, are persistently blocked. At sub-lethal doses imidacloprid can alter honey bee foraging and learning. Imidacloprid has been detected at levels of 5.7 μg kg-1 in pollen from French hives and foraging honey bees reduced their visits to a syrup feeder when it was contaminated with 3 μg kg-1 of imidacloprid. Foraging as well as hive worker bees and brood are likely to be continuously exposed to imidacloprid when contaminated food is collected and stored inside the hive. This may in the course of time be detrimental to the bee colony and ultimately cause colony collapse.