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Neonicotinoid insecticide travels through a soil food chain, disrupting biological control of non-target pests and decreasing soya bean yield

Neonicotinoids are the most widely used insecticides world-wide, but their fate in the environment remains unclear, as does their potential to influence non-target species and the roles they play in agroecosystems. We investigated in laboratory and field studies the influence of the neonicotinoid thiamethoxam, applied as a coating to soya bean seeds, on interactions among soya beans, non-target molluscan herbivores and their insect predators. In the laboratory, the pest slug Deroceras reticulatum was unaffected by thiamethoxam, but transmitted the toxin to predaceous beetles (Chlaenius tricolor), impairing or killing >60%. In the field, thiamethoxam-based seed treatments depressed activity–density of arthropod predators, thereby relaxing predation of slugs and reducing soya bean densities by 19% and yield by 5%. Neonicotinoid residue analyses revealed that insecticide concentrations declined through the food chain, but levels in field-collected slugs (up to 500 ng g−1) were still high enough to harm insect predators. Our findings reveal a previously unconsidered ecological pathway through which neonicotinoid use can unintentionally reduce biological control and crop yield. Trophic transfer of neonicotinoids challenges the notion that seed-applied toxins precisely target herbivorous pests and highlights the need to consider predatory arthropods and soil communities in neonicotinoid risk assessment and stewardship.

A multi-year field study to evaluate the environmental fate and agronomic effects of insecticide mixtures

A mixture of insecticides used in corn production was monitored over a three-year period in a field study to determine how long each persists in the environment, where each insecticide travels within the corn field, and the efficacy of using soil-applied insecticides with genetically modified corn. The genetically modified corn contained the insecticidal Cry1Ab and Cry3Bb1 proteins (Bt corn) and the Cry1Ab protein was found to persist only during the corn growing season in soil, runoffwater, and runoff sediment with highest concentrations measured during pollination. Very low concentrations of Cry1Ab proteins were measured in soil collected in the non-Bt corn field, and no Cry1Ab proteins were detected in shallow groundwater or soil pore water. Clothianidin, a neonicotinoid insecticide used as a seed coating, was detected in all matrices and remained persistent throughout the year in soil pore water. Tefluthrin, a pyrethroid insecticide applied at planting to control corn rootworm larvae (Diabrotica spp., Coleoptera: Chrysomelidae) populations, was consistently detected in soil, runoff water, and runoff sediment during the corn growing season, but was not detected in groundwater or soil pore water. Tefluthrin did not have an effect on root damage from corn rootworm larvae feeding to Bt corn, but did prevent damage to non-Bt corn. A slight reduction in grain yield was observed in the non-Bt, no tefluthrin treatment when compared to all other treatments, but no significant difference in grain yield was observed among Bt corn treatments regardless of soil insecticide application. In the current study, the use of tefluthrin on Bt corn did not significantly affect crop damage or yield, and tefluthrin may travel off-site in runoff water and sediment.

100+ Scientists Call on Obama’s Bee Task Force to Take Action on Pesticides

In a letter submitted for today’s White House “listening sessions” deadline, over 100 scientists from diverse disciplines (including Dutch toxicologist Henk Tennekes) cited the growing body of evidence that neonicotinoids and other systemic pesticides harm bees. These scientists called on leaders of President Barack Obama’s Pollinator Health Task Force to take action on pesticides to protect and promote healthy populations of bees and other pollinators.

Freshwater species have suffered a 76 per cent decline since 1970, an average loss almost double that of land and marine species

According to the Living Planet Report report, populations of fish, birds, mammals, amphibians and reptiles have declined by 52 per cent since 1970. Freshwater species have suffered a 76 per cent decline, an average loss almost double that of land and marine species. “Biodiversity is a crucial part of the systems that sustain life on Earth – and the barometer of what we are doing to this planet, our only home. We urgently need bold global action in all sectors of society to build a more sustainable future,” said WWF International Director General Marco Lambertini. Biodiversity declines in Africa highlight the intense pressure felt by tropical species. For the thousands of species tracked by the report, the tropics showed a 56 per cent loss across populations compared to 36 per cent in temperate zones. “The unique nature and natural resources of Africa are under more pressure than ever before. Life-sustaining ecosystems are rapidly degrading, thus compromising the future security, health and well-being of millions of African people, with the poor heavily and disproportionately bearing the brunt of these losses,” said Fred Kumah, Director of Africa at WWF International.

The world’s reptiles — turtles, snakes, lizards, alligators and crocodiles — are in trouble

The International Union for Conservation of Nature, which publishes an annual global roster of threatened and endangered species called the Red List, considers some 664 species of reptiles — representing more than 20 percent of known reptile species worldwide — as endangered or facing extinction. Meanwhile, the U.S. Fish & Wildlife Service considers about 10 percent of American reptiles threatened or endangered. The non-profit Center for Biological Diversity (CBD) considers reptiles “amazing creatures” with clever adaptations that have helped them survive for millions of years. CBD also points out that reptiles are valuable indicators of wider ecological health. “Because many reptile species are long-lived and relatively slow-moving, they suffer from disturbances like habitat loss or pollution for extended periods,” the group reports, adding that a diverse community of reptiles living in a given area is evidence of a healthy ecosystem that can support the plant and animal life they and other species need for food and cover.

Serious population decline of the red knot occurred in the 2000s

The rufa red knot (Calidris canutus) is truly a master of long-distance aviation. On wingspans of 20 inches, some knots fly more than 9,300 miles from south to north every spring and repeat the trip in reverse every autumn, making this bird one of the longest-distance migrants in the animal kingdom. Surveys of wintering knots along the coasts of southern Chile and Argentina and during spring migration in Delaware Bay on the U.S. coast indicate that a serious population decline occurred in the 2000s. The knot’s unique and impressive life history depends on suitable habitat, food and weather conditions at far-flung sites across the Western Hemisphere, from the extreme south of Tierra del Fuego to the far north of the central Canadian Arctic. Knots need to encounter these favorable habitat, food and weather conditions within narrow seasonal windows as the birds hopscotch along migration stopovers between wintering and breeding areas. For example, the knot population decline that occurred in the 2000s was caused primarily by reduced food availability from increased harvests of horseshoe crabs, exacerbated by small changes in the timing that knots arrived at the Delaware Bay. Horseshoe crab harvests are now managed with explicit goals to stabilize and recover knot populations.

Predatory Fish Have Declined by Two Thirds in the 20th Century

The removal of top predators has been called “humankind’s most pervasive influence on nature,” and it is as detrimental in the sea as it is on land. Consumers prefer predatory fish like grouper, tuna, swordfish and sharks to species lower on the food chain such as anchovies and sardines, providing strong incentives for fishermen to catch the bigger fish. Going after the more valuable predators first, fishing them until there aren’t enough left to support a fishery and then moving on to species lower in the food chain, a pattern sometimes observed in global fisheries, has been called “fishing down the food web.” New research by the team that coined the term attempts to determine how severely predatory fish populations have declined worldwide since the start of industrial fishing. Scientists analyzed more than 200 published food-web (interacting food chains) models from all over the world, which included more than 3,000 ocean species. Their results show that in the 20th century humans reduced the biomass of predatory fishes by more than two thirds and that most of this alarming decline has occurred since the 1970s.

In California, Washington, Oregon and Idaho, salmon are extinct in nearly 40 percent of the rivers they were known to inhabit

The rivers and streams of the Paci­fic Northwest used to be so full of wild salmon that fishermen liked to say they could cross the waterways on the fish's backs. If salmon were the only means of crossing the rivers, those fishermen would be out of luck today. In California, Washington, Oregon and Idaho, salmon are extinct in nearly 40 percent of the rivers they were known to inhabit -- at least 106 major stocks gone forever [source: Northwest Power & Conservation Council]. Around the world, the story is much the same: Global Atlantic salmon catches fell 80 percent from 1970 to 2000. In the United Kingdom, one-third of the salmon population is endangered according to the WWF, and in California and Oregon, the Pacific Fishery Management Council recently announced the strictest salmon fishing quotas in the region's history due to the animal's rapid decline [source: Young, Environment News Service]. The downward spiral of the salmon population is troubling for several reasons. This fish is far more than just a tasty source of omega-3s. Salmon are what's known as a keystone species -- like the engine in your car, their physical presence compared to the whole is rather small, but their importance to its functioning is vital. Not only are the fish a main source of sustenance for a variety of predators (more than 137 species), but their decomposing carcasses are a significant source of nutrients and fertilizer for trees [source: Hunt]. When the salmon go, the surrounding ecosystem likely won't be far behind.

Neonicotinoid contamination of global surfacewaters and associated risk to aquatic invertebrates: A review

Neonicotinoids, broad-spectrum systemic insecticides, are the fastest growing class of insecticides worldwide and are now registered for use on hundreds of field crops in over 120 different countries. The environmental profile of this class of pesticides indicate that they are persistent, have high leaching and runoff potential, and are highly toxic to a wide range of invertebrates. Therefore, neonicotinoids represent a significant risk to surface waters and the diverse aquatic and terrestrial fauna that these ecosystems support. This review synthesizes the current state of knowledge on the reported concentrations of neonicotinoids in surface waters from 29 studies in 9 countries world-wide in tandem with published data on their acute and chronic toxicity to 49 species of aquatic insects and crustaceans spanning 12 invertebrate orders. Strong evidence exists that water-borne neonicotinoid exposures are frequent, long-term and at levels (geometric means = 0.13 μg/L (averages) and 0.63 μg/L (maxima)) which commonly exceed several existing water quality guidelines.

Time dependent sorption behavior of dinotefuran, imidacloprid and thiamethoxam

In this research study, time-dependent sorption behavior of Dinetofuran (DNT), imidacloprid (IMD) and thiamethoxam (THM) in vineyard soil was studied. Sorption kinetics studies were conducted over a period of 96 hours with sampling duration varying from 0, 2, 4, 8, 12, 24, 60 and 96 hours. All three neonicotinoids exhibited very low sorption potential for the soil investigated. Overall percent sorption for all three neonicotinoids was below 20.04 ± 2.03% with highest percent sorption being observed for IMD followed by DNT and THM. All three neonicotinoids are highly soluble with solubility increasing with IMD < THM < DNT. Although, DNT has the highest solubility among all three neonicotinoids investigated, it exhibited higher percent sorption compared to THM, indicating factors other than solubility influenced the sorption kinetics. Low sorption potential of neonicotinoids indicates greater leaching potential with regard to groundwater and surface water contamination.