Worms and Flowers

Butterfly vs. Bt

Posted in Scientific by Lzyjo on September 29, 2009

PhotobucketI know, I’m not Sherlock Holmes, but there is a serious problem afoot that needs some investigating. Here is the first clue: On the East Coast the most prevalent butterflies are the Eastern Tiger Swallowtail in both its black and yellow forms. These pictures were taken last year in the middle of June.  One of their favorite flowers in these parts are the milk thistles. There are a ton of these thistles and they bloom a lot, but this year, not one butterfly on their flowers. Not one. In fact I saw two butterflies this entire summer. A black one quickly darted away from me while I was picking blackberries and a Yellow Tiger Swallowtail also darted away from me closer to the yard.

Second Clue: Bt, Bacillus thuringiensis, is a naturally occurring soil-dwelling bacteria and biological insecticide. Bt is a living organism very similar to Anthrax.  Bt, like anthrax, produces endospores a virtually indestructible  enclosure that protects the organism’s DNA. Endospores remain dormant until favorable conditions are met, then they replicates their own DNA, producing other compounds and toxins during the process. One of these is a crystal protein toxin produced by Bt’s cry gene. This cry toxin specifically effects larvae in many orders of the insect family. Bt lives in the soil and on plant material, specifically plant material that caterpillars need to eat. When caterpillars or any insect larvae ingest the cry toxin it becomes activated due to the pH in their guts. The toxin basically causes the cells in the thin gut lining to explode, quickly and effectively killing the insect. This is exactly how Bt insecticides and genetically modified Bt crops work.Photobucket

I lifted the following paragraph from Wikipedia’s Bt page. “Because of their specificity, these pesticides are regarded as environmentally friendly, with little or no effect on humans, wildlife, pollinators, and most other beneficial insects”

oh, except, ants, beetles, butterflies,  flies, mosquitoes, moths,  nematodes and so on…

Granted, we don’t want mosquitoes with West Nile Virus flying all over the country, but do we really prefer Bt killing every insect in sight like an invisible grim reaper?

Sources:

Wikipedia Bt]

UPDATED INFO: Bt Correction