Community IPM

West Nile and Mosquitoes – What to do?

communityipm — Fri, 21 Sep 2012 17:21:26 +0000

By mid-September the United States was pushing close to 3,000 cases of West Nile and over 120 deaths, at least 50 of those in Texas. West Nile is a virus that pops up every year in the U.S. as it is endemic to our region. This year, weather conditions (and possible other environmental and nonenvironmental conditions) have increased mosquito populations and transmission of the disease. Now, drought doesn’t exactly make one think that mosquitoes will rise, but when we are in a drought and experience a good rainfall, both mosquitoes and birds go to those pools of water. Birds are the reservoir for the West Nile virus. They hold the virus in their bodies in high numbers but do not exhibit symptoms of the virus, and thus continue to live and keep it in the population. Birds carrying West Nile are bitten by a mosquito while both are a water source, and when we have fewer water sources because of a drought, the two key players in the West Nile saga have a better chance of meeting.

The Center for Disease Control (CDC) estimates that 1 in 150 people who contract West Nile will show symptoms. Most of us have no idea! Those few people that come down with symptoms usually have the mild symptoms (thank goodness) – fever, aches, headache, swollen lymph nodes, rash. Very few people will experience severe symptoms: severe headache, neck ache, muscle weakness, vision loss, paralysis, disorientation, and coma.

There is not treatment or cure for West Nile (only treatment of the symptoms), so the best thing is prevention! Avoiding mosquitoes when they are most active, during dawn and dusk is a great idea. If you have to be outdoors, wear light colored, loose fitting, long sleeves and pants, and wear mosquito repellent. The Environmental Protection Agency recognizes four active ingredients as being approved, labeled insect repellents that provide relatively long lasting repellency to disease carrying mosquitoes. Those active ingredients are DEET, Picaridin, Oil of Lemon Eucalyptus* or PMD, and IR3535. For more information on this, visit www.cdc.gov or www.epa.gov.

As a homeowner, treating all the areas around your home for adult mosquitoes isn’t really the best option. It is generally short term and you will never totally eliminate all the mosquitoes. We end up applying too much pesticide, exposing ourselves and the environment, and spending a lot of money. It is much better to go to the source and prevent the mosquitoes from becoming adults. Mosquitoes require standing water to lay their eggs and complete the larva and pupa stages of their life cycle. Water that is still, stagnant, high in organic matter or debris, and generally dirty is a great breeding ground for mosquitoes. Look around your yard for breeding sites: animal water dishes, potted plants, saucers under pots, trash can lids, kiddie pools, bird baths, water running off a gutter, A/C condensation dripping, ponds, low laying areas, etc. are all potential mosquito breeding sites.

Dump the water if you can, and dump it every couple of days. Mosquitoes can complete their lifecycle in 6 days during high temperatures, so a weekly look around the yard is too long! If you cannot dump the water, use Bti mosquito dunks or granules. Bti (Bacillus thuringiensis israelensis) is a bacteria that ONLY effects mosquitoes. You can safely apply it to bird baths, horse troughs, fish ponds and know only the mosquitoes will be effected – no other animal or insect.

Recent, long, soaking rains have increased water pools that will allow more mosquitoes to breed. Cooler weather may slow down their development, but they will be active well into the fall and I anticipate the cases of West Nile will continue to increase until the weather dips into 60s and 50s. Protect yourself by using insect repellent and remember next spring and summer we will likely face the same issues.

For more information about West Nile, visit the CDC’s website: http://www.cdc.gov/ncidod/dvbid/westnile/index.htm or Texas A&M AgriLife’s Bookstore and use the keyword mosquito: http://agrilifebookstore.org

by Molly Keck
Integrated Pest Management Program Specialist
http://bexarento.blogspot.com/

Vegetable Gardens Beware!

communityipm — Fri, 21 Sep 2012 17:20:32 +0000

If you are growing a veggie garden this fall, it’s a safe bet that cabbage loopers will make an appearance. Cabbage loopers are small (less than 1.5 inches), green colored caterpillars that prefer to hide in the folds of cabbage, broccoli, lettuce, cauliflower and any other plant that forms a head. They may like those veggies, but they will eat pretty much anything!

Cabbage loopers cause small, irregular shaped holes in the leaves of the veggie. This either makes the plant stressed or reduces the crop yield – and who wants to eat holey lettuce!?!

Cabbage loopers should be managed early on in the growing season. Watch plants very closely for holes and at the first signs use a pesticide labeled for caterpillars. Great options that are also organic are Bt (Bacillus thuringiensis) and Spinosad products. Bt worm killer is effective against caterpillars only, so all your beneficials and other insects will not be harmed. If you have a butterfly garden, however, be careful for drift, as Bt will kill ALL caterpillars that consume it. Spinosad is a little more of a broad spectrum pescticide, but is relatively benign on beneficial insects.

Remember to follow all label directions when mixing and applying pesticides.

by Molly Keck
Integrated Pest Management Program Specialist
http://bexarento.blogspot.com/

Rare Spider Stops $15M Construction Site

communityipm — Fri, 21 Sep 2012 17:18:05 +0000

We made the news again for something insect related. Except its not an insect, it’s a rare spider, called the Bracken Bat Cave Meshweaver. This rare spider has not been seen in 30 years, but was found by a biologist with U.S Fish and Wildlife while inspecting the construction site for endangered or threatened species. The construction site is at Highway 151 near Weisman Road and the area has karst formations or features. Karst features are limestone outcroppings that can be caves and are usually subterranean. Karst features are known to be a home for many rare, threatened, and even endangered species of arthropods such as the Bracken Bat Cave Spider.

I know it seems silly to stop a 15 million dollar construction site after seeing just one little spider, but it goes to show that all living things have a purpose and as humans we have a responsibility to help preserve nature and the ecosystem.

While I don’t know much about the biology and benefits of this spider, it may play a very important role in the karst ecosystem. Biological magnification is always something to consider when you eliminate one species. Who knows what preys on the spider, or what it preys on and how the food web could be altered, eventually impacting humans. We may also use this little spider to learn things that could benefit us in the future. You never know and everything has a place!

by Molly Keck
Integrated Pest Management Program Specialist
http://bexarento.blogspot.com/