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Pesticide is costly for bees, then birds, then?

By Dave Armstrong - 20 Mar 2013 10:57:0 GMT
Pesticide is costly for bees, then birds, then?

While the northern bobwhite or Virginia quail, Colinus virginianus, was used in pesticide research, almost all bird species have NEVERbeen tested to see what specific reactions they have - Bobwhite Quail Image; Credit: © Shutterstock

The way in which we have allowed concerns about neonicotinoid insecticides to go unnoticed is parallel to the Silent Spring ignorance that reigned supreme for Rachel Carson. In 1990, all farmers and horticulturalists needed a magic touch to relieve them of resistant pests. While bees and other useful pollinators were a concern at the time, and still are, the supreme effectiveness of these modern insecticides prevented their proscription.

As they persist within the ecosystem for long periods, neonicotinoids have the opportunity to concentrate in bodies and in groundwater. Aquatic birds are the first to have been noted suffering from neonicotinoid effects. Lethal doses consist of single coated kernels of corn. Imidacloprid can kill with a coating on a wheat grain! Reproductive organs are affected even more readily. The problem is that groundwater levels have also now reached lethal levels worldwide .A rigorous scientific investigation is needed to reveal the aquatic risks involved, before we find ourselves back in the 1950s.

Usage is still growing rapidly for almost all insecticidal purposes, especially for cash crops and other agricultural areas where pests always prove major destructors. Resistance to pesticides such as organochlorines and carbamates at that time was building in many species. Public anxiety worldwide condemned the DDT and dieldrin relatives to the scrapheap (hopefully not literally) as many animals such as the peregrine suffered more than just the thinning of their eggshells, but near extinction in many countries. According to the ABC (American Bird Conservancy), bans should be in place now, to avoid a major ground-water and wildlife catastrophe. Seed treatment especially seems ripe for a total ban, as birdlife will soon concentrate the toxic effect for their predators, and naturally affect the human food chain too.

The worldwide solution to pest control avoided widespread scientific criticism as neonicotinoid producers advertised multiple uses. Bird and mammal toxicity records were noted, then ignored. Even recently, clothianidin and thiamexonam were allowed precaution notices instead of regulation as to their use for both terrestrial and aquatic systems. While they are less acutely toxic than their predecessors, in birds they seem to vary in their effects. Only mallards and bobwhites, as seen above, were tested for toxicity. Debilitation of birds will also take place long before any acute toxic effect and a partial paralysis actually goes unrecorded by researchers. Birds seem to become paralysed with low doses, while testicular effects and embryonic development are affected by very much lower dosage.

One of the most unforgiveable myths about modern insecticides is that animals are repelled by them. They are not! Laboratory tests don't show sufficiently how hungry birds behave in a field. Only grey partridge decline has been linked to pesticide use (British research), but obvious links are there to be seen. Nearby, in the Netherlands, loss of insect biomass is causing many species to fall greatly in numbers. In this one small country, research shows also that they have much higher pesticide levels in groundwater than those admitted in the US, for example.

Freshwater invertebrates such as Daphnia, that are insensitive to neonicotinoids, are rare. Most invertebrates are much more sensitive, like their insect relatives. Unfortunately, the US authority, EPA, has no diagnostic tool to assess poisoning of wildlife. Bees are known to be poisoned and concerns are regularly expressed that a third of the American diet depends on these pollinating insects. Birds, aquatic invertebrates and wildlife generally have been neglected in these considerations.

With spreading usage of these "safer" insecticides, even to non-agricultural industries, we now have a Silent Spring situation. Like it or not, we have to stop using such controls so glibly, and act, universally, right now!

This young lady, a northern cardinal, is likely to suffer paralysis from ingesting just one grain of wheat coated with neonicotinoids

This young lady, a northern cardinal, is likely to suffer paralysis from ingesting just one grain of wheat coated with neonicotinoids; Cardinal Bird Image Credit: © Shutterstock

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Topics: Birds / Pollution