Tuesday, March 18, 2008

The Birds and the Bees

The following post was sent to me by John Green of Longview, WA and concerns the possible link between certain insecticides and Colony Collapse Disorder in honey bees. The suspect insecticides belong to a new class called neonicotinoids and one of the more common active ingredients is imidacloprid.

In 2007, many newspapers ran articles concerning the disappearance of bees, crop pollinators and songbirds. Farmers are becoming alarmed that there will not be enough bees around to pollinate their crops. These crops are our food supply. So what is happening to the bees?

A look at our life styles gives us the answer. Our dependence on chemicals permeates every aspect of our lives. Walk through garden supply departments and see rows and rows of chemicals. When citizens douse their lawns and gardens with pesticides to try to have the greenest lawn or the prettiest flowers in the neighborhood, they use chemicals that are toxic to bees. In our pursuit of perfect produce, farmers spread pesticides, which are considered highly toxic to bees.

Many cities spread pesticides to control the aphids and leaf miners and other insect “pests”. One of the most commonly used pesticides is Imidacloprid (a neonicotinoid class of pesticide), which was outlawed in France because of its toxicity to bees. This chemical stays in the soil for months, and in some cases years. Even small amounts will disorient bees to the extent that they cannot find their way back to their hives. The bees also lose the ability to groom themselves, exposing them to mite and virus infestation and death. Imidacloprid is applied to the soil within a tree’s drip-line, where it is absorbed by the root system and then spreads to the leaves and flowers where bees forage. Imidacloprid is not just absorbed by the target trees, but by any flower or plant growing in the soil where it is applied. Even clover, which grows under the trees becomes deadly to the bees which forage there. Imidacloprid is also toxic to earthworms, which live in the soil and to fish if it enters the storm water that drains into our lakes, streams, and rivers.

Our songbirds are also affected by pesticide use. Research has shown that birds which eat insects which have eaten pesticides become sick and in many cases, die. At one time DDT was thought to be safe, until many years elapsed and we discovered how detrimental it was to the environment and the creatures living in it. Could imidacloprid be the next case of DDT? Each of us can help curb a natural catastrophe (and a potential risk to human health) by not applying pesticides to our own yards or farms and also by calling your city to ask them to stop using chemicals, which are threatening our birds and bees. There are more environmentally safe ways to deal with harmful insects.

Remember, pesticides cannot distinguish “good” bugs from “bad” bugs.


References

Possible culprit identified in decline of honey bees
Earth & Sky Radio Series about Colony Collapse Disorder
Environmentally friendly pest control


Saturday, March 08, 2008

Spider Bites - Myth vs. Reality

We get more visitors to our Bugs site looking for information about spiders, spider identification and spider bites than just about any other topic. Most people have an innate fear of spiders and believe that most are dangerous; even small spiders provoke this fear.

The truth is most are harmless or even beneficial and the few that do have a venomous bite may not be as dangerous as we once believed.

In the US there are three spiders that get blamed for most of the so called "spider bites" that end up in emergency rooms. Where you live largely determines which species gets the blame. The three common culprits are: brown recluse, black widow, and hobo or aggressive house spider.

Brown recluse spiders are only found in the south central US. Researchers have tried to find specimens of the spider outside this range but have repeatedly failed. Despite the lack of actual spiders, even the medical community continues to report bites and ulcerating ("flesh eating") wounds attributable to brown recluse -- what's going on here?

Turns out there's a skin bacteria called methicillin-resistant Staphylococcus aureus, or MRSA that causes open, ulcerating wounds that researchers now believe accounts for many of the wounds that were once attributed to brown recluse spider. Wounds are very red, tender and very slow to heal.

Bites from the other "flesh-eating" spider, the hobo spider, which is found mainly in the Pacific Northwest, and often misdiagnosed as brown recluse, results in similar wounds. The MRSA bacteria may well be involved with reported injuries from this spider, too. Hobo spiders are not even considered to be venomous in their native range in Europe.

To confirm a MRSA infection requires a laboratory culture and several days. Most physicians won't bother because in the end the treatment (spider bite vs. bacterial infection) is the same.

On the other hand, black widow spiders, which occur throughout the US, have a venom that acts on the central nervous system and can be very dangerous, even life-threatening. Black widow bites do not result in ulcerating wounds but rather affect muscles and nerves. Pain, tremors and breathing difficulty often set in within minutes of a black widow spider bite.

If you believe you have been bitten by a spider try to collect the specimen and have it identified. Contact your local county Extension office for help (free), or contact us but we have to charge for spider identifications.

The electron micrograph photo above was taken by Marc Castagna. The image shows the fangs (inwardly pointed "chelicerae" in lower part of photo) and pedipalps (upper, "boxing gloves") of a spider. In life the fangs are only about 1/32".

Thursday, March 06, 2008

Drain Flies Breed in the "Gunk" In Your Drains

drain, or moth flyEvery once in awhile I get an e-mail with a question about the "small, black bugs that seem to be coming out of the drains in the bathroom and kitchen". These are called drain flies (see photo) and are common and usually no reason for concern but it may mean it is time to clean out the "gunk" in your drains!

Drain flies, also called moth flies (another image of drain fly) are small (~1/10") hairy flies that are commonly found in kitchens and bathrooms. Larvae of drain flies can develop in the organic, gelatinous material that builds up inside pipes and hence can be very common around sinks. They are also common outdoors near sewage plants and waste ponds. Adult drain flies are covered with scales that makes the fly look like a tiny moth. Flies may be attracted to lights and windows. Eggs are laid on the gelatinous film that forms in pipes or in sewage treatment facilities. Larvae develop in this rich organic material.

The drain flies are harmless but a close relative, the sand flies, actually transmit a serious disease called leishmaniasis. Leishmaniasis does not occur in the US.

Fly numbers can be reduced by removing the organic, gelatinous material that forms inside drain pipes. You can use a stiff brush or one of the relatively new bacterial/enzyme-type drain cleaners. Regular use of a drain cleaner will remove the layer of gunk and prevent fly development. There's no reason to use insecticides. Foaming-type chemical drain cleaners will work as well.

Don't use the bacterial/enzyme-type drain cleaners on clogged drains. For drains that are clogged you'll need a chemical drain cleaner or plumber's snake (or a plumber). The bacterial/enzyme cleaners are only intended to remove the organic film (gunk) that forms on the walls of drain pipes and such.