Bt – A bacteria which is a natural insecticide

Here's a gardening term you can use to impress your friends. Practice saying it til it rolls off your tongue easily as though you use it several times daily: Bacillus thuringiensis (bah-SILL-is thur-in-jee-EN-sis),commonly known as Bt, is a bacterium that occurs naturally in the soil, common all over the world. Bt acts as an insecticide by producing proteins that react in the gut of some insects, paralyzing their digestive systems. The insects stop eating and quickly starve.

Because of its specificity, Bt is not harmful to plants, people or pets, birds, fish, wildlife, pollinators, and most other beneficial insects. Bt can be applied using conventional spray equipment but, because the bacteria must be eaten by the insect to be effective, good spray coverage is essential. You should avoid breathing the powder or spray when applying Bt to your plants. Bt degrades fairly quickly in sunlight, so it will not persist in your garden. Some strains persist for less than 24 hours while others remain viable for about a week.

The kurstaki strain of Bt kills only caterpillars that feed on leaves and needles. Bt kurstaki is especially useful for eliminating corn earworms and those little green cabbage worms that like to infest broccoli, along with tent caterpillars and webworms that damage trees and shrubs. Because Bt kurstaki will kill most any type of caterpillar, it should be used sparingly if you want to attract butterflies to your garden.

Another type of Bt, the israelensis strain, will kill the larvae of mosquitoes, black flies and fungus gnats. This is good news for those of you who suffer through mosquito season each summer!

The san diego strain of Bt is a good choice for controlling the Colorado potato beetle. Potato beetles can quickly reduce potato plants to shreds, but Bt san diego stops the larvae in their tracks before they can do significant damage.
Bt was first identified in 1911 when it was discovered that it killed the larvae of Mediterranean flour moths in a mill in Thuringia, Germany. It was registered as a biopesticide in the U.S. in 1961. In 1983, the World Health Organization used Bt in West Africa to control disease-carrying blackflies.

Bt became available to home gardeners in the 1950s, and in recent years, new strains have been developed that attack an even wider range of insects. They appear under trade names such as Dipel and Thuricide.
Research to transfer insect resistant genes from Bt to crop plants is well under way. Corn, cotton, tomatoes and potatoes are some of the many commercial crops for which Bt insect resistance is proving useful.
Bt is very selective - different strains of the bacterium kill different insects and only those insects. Various strains of Bt are used to control spruce budworms and gypsy moths in forests, cabbage worms in broccoli and cauliflower, loopers or budworms in cotton and tobacco, and leaf rollers in fruits.

SPRING INTO GARDENING CONFERENCE

We are very pleased with the response to our Spring Into Gardening conference. And there is just over one week for you to join in the merriment. Deadline for on line registration is February 23 or postmark deadline is February 20.

If you have access to a computer, the very easiest way is to register on the Extension's wonderful website. The address is at the end of this article. If you register online, the great secure website keeps all our records for us, which saves us a lot of time. (While you're on the website, take time to read some of the helpful articles there.) You may also mail or hand-deliver your payment to the Extension office.

Check-in is from 8:00 to 8:45 a.m. The program begins at 8:45 a.m. and concludes at 12 noon. It will be held at the beautiful new LifeSpan Center between Mattoon and Charleston IL. That's worth the trip in itself!

Three special guest speakers are lined up to share their knowledge; Sandy Mason, the Horticultural and Environment Unit Educator with Champaign County Extension, will talk about "Tried and True Perenniels"; Tony Bratsch, Horticulture Extension Educator with Effingham Extension Center will discuss "Flowering Shrubs and Trees". Read below about the 3^rd speaker. There will be delectable refreshments, delightful door prizes, garden items for sale and silent auction items, all for only $15.00.

Marsha Overton has highlighted Sandy Mason and Tony Bratsch in her recent articles; I have the pleasure of telling you about Shane Cultra.

If you are a regular watcher of the Illinois Gardener program, you undoubtedly have seen Shane appearing as a panelist. I garnered this information from the Country Arbors website:

1865 - The Onarga Nursery Company was founded in 1865 by Robert Blaine Cultra upon his return from the Civil War. He walked on foot through the rural areas and the fledgling communities selling strawberry and raspberry plants, and fruit trees. In the tradition of Johnny Appleseed, he tried to trod every dusty path and byway for nearly twenty years. Each year the business grew a little larger and his reputation as a good nurseryman increased.

Fast forward 130 years:

1995 - T. Shane Cultra joined his father P. Terence Cultra, thus becoming a fifth generation nurseryman.

2005 - T. Shane Cultra assumed the responsibility of Chief Operating Officer, replacing his father P. Terence Cultra , thus becoming the guiding force behind the future vision of Country Arbors Nursery.

Shane will be telling us "What's New in the Plant World for 2009", as well as bringing items from his greenhouses and garden shop to sell, some of them newly-arrived, so you will have first pick!

RIGHT NOW would be the perfect time to register… You'll be glad you did! Go to: http://web.extension.uiuc.edu/coles/