Friday, April 25, 2008

What are these holes in my plants?

The majority of questions that I fielded last weekend were regarding what could be chewing holes in the foliage of plants. Caterpillars, grasshoppers and leaf beetles come immediately to mind. Of course, everyone also wanted to know what they could do about the bugs.

First, look at the damage to determine if it's old or new damage. New damage will appear "fresh" and be green around the edge of the wound. Old damage will show browning around the area that has been chewed. If you have old damage, it's most likely too late to provide treatment as the bugs could have moved on to bigger and yummier plants. If it's new damage, first look for the bugs that could be doing the damage. This is where a bit of basic entomology comes in handy so you can properly identify what you're seeing. Try looking images up online (make sure to utilize a reliable resource such as a university or extension service). The TAMU entomology website hosts a variety of resources here:
If you can't find what you've got, you can always contact me for help.

With insect pests, it's usually better to try managing them early when they are still small. Why? Well, for one, they're small which is often easier to kill. Secondly, they are not as mobile as in the adult stage. Remember, adult insects have wings and can fly away, immatures have to hop, walk or crawl.

So for chewing insects, what are your options for control? Cover the plants with row cover to exclude the insects or hand pick the insects (wear leather gloves in case they try to bite you) from the plant and drop them in a bucket of soapy water. If you have a lot of insects or a lot of plants, you can try using a shop vac to suck the insects off the plants. Other options would be using products with active ingredients such as spinosad (get good coverage on foliage since insects have to consume this for it to work!), neem, d-limonene, pyrethroids (cyfluthrin, bifenthrin, deltamethrin, etc.) or carbaryl. Remember, when you choose pesticides, find ones that have the location you are treating on the label and follow all label instructions!

Friday, April 18, 2008

Austin Garden Tour

Whew! It's's been a very busy week! I checked my field plots in Georgetown on Monday and I'm doing another check this afternoon; I did a three hour CEU training for city employees; I took a great bead class the past two days with Andrea Guarino-Slemmons and tomorrow is the Master Gardener Home Tour. I get the pleasure of hanging in Patty Leander's yard to talk about bugs (pests, beneficials or whatever problems you're having in your yard). If y'all have the opportunity, attend the Garden Tour and you'll have the opportunity to see a variety of wonderful local gardens! I've been to Patty's before and I can tell you that it's the most amazing vegetable garden I've seen. I can only aspire to someday have a tenth of the vegetable garden she's amazing...they have raised beds, make their own compost, test new varieties of veggies to see how they grow in Travis County.

The Garden Tour has 7 gardens to visit with people at each location to talk about a variety of topics ranging from rainwater collection to bulbs in Central Texas to installing drip irrigation. For more information, go here:

As for me....I'm off to kick some fire ant mounds!

Monday, April 14, 2008

Field trial for fire ants

Well, I'm a bit off my schedule for attempting to post each Friday. I'm not going to beat myself up too much as I was working, but fortunately, it was outside in the wonderful sunshine instead of behind my desk in a drably painted office. Speaking of which...I should paint my office a brighter color...maybe lavender.....wonder if I could get away with it?

Anyway, on Friday I drug my husband with me to set up a field trial outside the Extension office in Georgetown. It's always nice to have help when doing field work and Alan is always a big help. He's especially attentive now, sometimes to the point of being annoying, as I'm pregnant and he doesn't want me lifting heavy objects, being within 5 miles of a pesticide, etc. Not that I had plans of handling pesticide, my doctor would be very upset as I was told this was a big no-no last visit. And yes, you heard correctly, there's going to a little Brown soon to terrorize the planet...prepare yourselves!

Back to the field work....I'm expanding upon a trial that I carried out last fall testing aspartame (the artificial sweetener) for managing individual fire ant mounds. I'm sure some of you have read on the Internet or got an email saying how it was developed as an ant poison. Well, I'm now carrying out field trials to see if it actually will get rid of the little buggers. The trial from last year showed that the aspartame did nothing to kill the ants- the aspartame treated plots showed no significant difference from the control plots where no treatment was done. This year, after treating with aspartame, I watered it into the mound since some organic sites say that this stimulates the product to kill the ants. We'll see what happens.....

By the way, if you're a nerd like me or just want some very dry reading material, you can find the aspartame field trial plus all of the field trials carried out by the fire ant group here:

It's the one titled "2007 Urban IPM Handbook". It's a pdf file that's quite large so it may take some time to download.

Friday, April 4, 2008

Twig girdlers- amazing creatures!

When I first started with Extension, someone brought in a bag of twig tips that appeared to have been sawed off, very neatly. This led to my discovery of twig girdlers. I had a few questions this week on twig girdlers, so I thought I'd add information here so more people could learn about these cool beetles. Yes, they can be somewhat of a pest when they are munching on your tree, but you really have to admire their precision.

Twig girdlers are a type of longhorned beetle (they get the longhorn part from their long antennae, not because they are affiliated with UT, or should I say TU for all those good Ags). After mating, the female beetles chew a circular notch around twigs or small branches of the tree. Eggs are laid into notches chewed in the bark above the circular notch. Larvae hatch and tunnel under the bark of the twig.

Since the beetle "girdles" branches, the tips eventually die and fall off the tree. This is usually when I get phone calls since branch tips are "mysteriously" dropping from the tree with no visible insects (hint: the insects are inside the branch tips). Unfortunately, it is very difficult to catch the beetles in the act, so spraying really does not help manage the beetles. Sanitation is your friend- clean up and dispose of the twigs and small branches that have fallen off the tree as they contain larvae.