Category Archives: Insects Abound!
Just when I thought we had the cabbageworms under control, another caterpillar comes along and attacks another plant. This time it’s the sweet potatoes!
The culprit was pretty easy to find. I turned over the first leaf that looked promising and saw this…
They look a lot like tussock moth caterpillars, very similar to some that we had on the sunflowers earlier this summer. Sweet potatoes are supposed to be relatively trouble free, so this is a little surprising. After doing a little research, it sounds like you aren’t supposed to worry about late-season leaf eating pests on sweet potatoes until they are 30% or more defoliated. I don’t think we’re quite there yet, but we may treat anyway. The Dipel (Bt) would most likely be effective here as well. I’ll keep you posted.
Yesterday morning we inspected all our Brassicas to see if we still had more caterpillars to deal with.
Um, yes. Yes we did. I know you see the bigger cabbageworm, but do you see the tiny one too? It’s along the purple midrib. These guys start really small but eat and grow quickly. Yuck. We also found some eggs that haven’t yet hatched.
We dusted with Dipel Dust to see if we could get better control. Of course, with the shaker cans, it is a real challenge to get even coverage and not put on too much. If we aren’t seeing better control by later in the week, we may have to bring out the big guns…I saw that one single cabbage butterfly can lay up to 300 eggs in its lifetime. I really don’t want these caterpillars to get to the adult stage!
Look what got munched on over the weekend?
I knew we were going to be fighting a long, grueling battle against the cabbageworms this fall, but I (mistakenly) thought that they wouldn’t start hatching out and eating until today or tomorrow instead of over the weekend. To see how quickly they started, there was virtually no sign of them on Friday. This morning the plants look like Swiss Cheese. UGH! I sprayed Spinosad this morning, and we will probably dust with Dipel either tomorrow or later this week.
Since we’ve been talking about bugs and pests recently, I thought I would share this video from our Entomology Specialist, Dr. Ray Cloyd.
All of a sudden last week the population of bugs, pests, and other problems seemed to explode in the Demo Garden!
All of a sudden near the end of last week the spider mites came on strong. This poor specimen is on the ‘Iron Lady’ tomato. It may be resistant to blight, but it is clearly NOT resistant to spider mites. There are several plants with varying numbers of spider mites on them, but this is one of the worst. The typical “first” line of defense is to spray with a hard stream of water. Given the humidity, the next option is neem oil, horticultural oil, or insecticidal soap. These products need to be sprayed every 5 days or so when it is hot, until new damage isn’t occurring. Unfortunately, is you spray when it is hot out, they can actually damage the plants, so you need to spray in early morning.
In the realm of four-legged, furry varmints, it appears that we have some critter that is enjoying the almost-ripe tomatoes. My guess would be a squirrel, because of the bite marks and also because we’ve had that problem before. The ants are just opportunists here!
I’ve also seen stinkbugs around the garden, which is an insect we don’t normally see a lot. Here’s a stinkbug on one of the cherry tomatoes.
Here’s another look at a stinkbug, this time on one of the eggplants. Stinkbugs are “true bugs,” and they feed on plants and fruit by puncturing and then sucking out the juices. On tomato fruit you will often find yellow or white spots just under the skin where they have been feeding. They don’t damage the edibility, just the prettiness. They can be pretty destructive though given a high enough population. They can also feed on the plants themselves and can have similar effects to aphids and spider mites. How to get rid of them? Well…it depends what you are willing to do. The reality is that it is pretty difficult to kill those hard-backed bugs. Since we aren’t seeing very many of them, we aren’t going to do much at the moment, which we will probably regret in a few weeks.
The Arkansas Traveler tomatoes all of a sudden are showing these “crop circles” on the fruit. To me, this looks like Tomato Spotted Wilt Virus. The plant doesn’t look particularly bad, although I commented earlier on the fruit being smaller than advertised. A virus would partially explain that. There is perhaps a little bit of necrosis (dead areas on leaves) at the shoot tips. The question is how it got the virus. This virus is typically transmitted by thrips in a greenhouse. Well, this plant was raised in my office, and I don’t think there were any thrips or infected plants for the thrips to pick up the virus. My guess would be that it was infected with the virus outside, either by thrips that picked up the virus last year and overwintered or infected thrips that were on one of the plants that did come from a greenhouse. At any rate, there’s nothing we can do about it now.
This is a pepper with a bad case of sunscald. Typically tomatoes and peppers are the most susceptible to sunscald, especially when there is lots of hot, bright sun. Keeping plants healthy with lots of leaf cover is the best option. Some varieties are better than others as far as shading fruit. At other times if you are having a very severe problem, providing a little additional shade would be the only option, which can sometimes be a logistical challenge in a garden!
And also these little white caterpillars. I think they are just a type of wooly bear caterpillar, even though they are white. If anyone knows differently, please let me know! These guys are having quite a meal of sunflower leaves. At this point, I’m not going to do anything about the bugs on the sunflowers. Now if they encroach onto a vegetable…
Some of the eggplant leaves are also looking a little bit Swiss Cheesy. I couldn’t find anything on the plants, although my suspicion is cucumber beetles. I found a couple flea beetles, but they typically cause pinhole size damage. I’ll be keeping an eye on the eggplant to monitor the damage and to see if I find anything doing the chomping. When you see the pile of eggplant we harvested today, you won’t be to concerned about our plants!
If you remember from a couple weeks ago, I showed some pictures of the Chocolate Cherry tomato and was suspicious of either a fungus or bacterial canker on the plant. Well…I sent a sample to our plant pathology lab, and they said that it was scorch. I’m not convinced, because there were lesions on the stems. They could have been from one of the hail storms. At any rate, the plant is not recovering and seems to still be in decline. We removed it today. The neighboring roma seems to be developing some sort of ailment, but it might just be a combination of spider mites, early blight, and a slight nutrient deficiency.