[Tweeters] Toxic Threats to Grassland Birds

Liz Hemberry lizhemberry at hotmail.com
Tue Mar 12 13:01:53 PDT 2013

My wife and I are pear growers in the Upper Wenatchee Valley. In our industry insecticides are used. While we are not experts in the chemistry of all pesticides we do have quite a bit of knowledge in this area. It seems to me that if insecticides were the cause of the decline of grassland species there would also be a decline of other species as well. Yet it sure seems like there are just as many Starlings, Violet Swallows, Flickers, and other species that nest in our orchards as there has ever been. If Sage Grouse is declining and Gray Partridge is thriving in a particular area wouldn't that suggest loss of habitat that is replaced by farming? Growing up on an orchard and then later becoming the owner I have been witness to the evolution of pesticides. In 1972 we used products such as Parathion and Morestan. These basically killed any and all pests that they contacted. Today, pesticides are designed to attack the target pest while preserving the beneficials. Many pesticides are systemic, meaning that the pest has to feed on the leaf in order to be affected. In pears, the number one pest is a small fruit fly sized bug call Pear Psylla. Like all insects it goes through a metamorphosis. The nymph of this critter has 5 stages. The insecticides that we use can only kill the first two stages. If you want to tell what stage the nymph is in you need to view a leaf through a magnifying glass. If you come to the Wenatchee Valley right now you will see many orchards that have been sprayed with a white substance known as Kaolin Clay. This is a mined product that is contained in toothpaste. It does not kill any insects. It does interrupt the ability of Pear Psylla to lay viable eggs. This is just another example of how pesticides have evolved. Ken Hemberry> Date: Tue, 12 Mar 2013 12:03:15 -0700

> From: isparrow at seanet.com

> To: tweeters at u.washington.edu

> Subject: [Tweeters] Toxic Threats to Grassland Birds


> Subject: Toxic Threats to Grassland Birds


> The following editorial appeared in the New York Times today. It

> indicates more problems for our grassland species.


> Irene Potter

> Tacoma, WA

> isparrow at seanet.com


> March 11, 2013 New York Times

> Toxic Threats to Grassland Birds


> Ornithologists agree that in the United States no group of birds is

> declining faster than the grassland species that live in or migrate

> through agricultural areas. These include, among others, various sparrows,

> eastern and western meadowlarks, bobolinks, horned larks and at least two

> kinds of owl. Scientists have generally agreed that the major cause is the

> fragmentation and loss of prairie habitat, the conversion of grassland to

> farmland as well as alterations in established farmland.


> But a new study by two Canadian toxicologists raises an old specter. They

> found that collapsing bird populations were more strongly correlated with

> insecticide use than with habitat alteration — that, in fact, pesticides

> were four times more likely to be linked with bird losses than any other

> cause.


> This would not have come as news to Rachel Carson, whose most famous book,

> “Silent Spring,” documented the disastrous effects of DDT on birds. DDT

> was banned in 1972, but it was followed by organophosphate and carbamate

> pesticides that were also highly lethal to birds. And while these

> pesticides have since been largely withdrawn from use, a new generation of

> nerve-agent insecticides called neonicotinoids could pose a further

> threat.


> These insecticides are now under review by the Environmental Protection

> Agency. They have caused huge die-offs of honeybees in Europe and provoked

> an uproar among scientists, not least because the studies that purported

> to establish their safety were financed by pesticide manufacturers. We

> hope that the Canadian study, establishing a clear link between pesticides

> and grassland bird losses, will cause the E.P.A. to consider the next

> generation of insecticides in a more critical light.





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