Sunday, March 1, 2015

Flea Beetles

Well, I'm experiencing my first run in with flea beetles. I wonder what took them so long to find me? It's been years. 

At first I wasn't aware that the problem I was seeing in my bean plants was due I flea beetles. Heck, I've never seen flea beetles before, so I didn't recognize them for what they were. I had planted a short row of green beans in a never-before-planted area. So I knew the soil was poor. Thus I wasn't expecting much out of the beans. The plants started out ok, then their leaves started looking bleached. The plants were small and stunty. I assumed the soil was the problem. The pH was a bit low, so I watered in a tad of wood ash and bone dust. I also gave the plants a shot of liquid fertilizer. They got worse. The leaves started looking really bad with some curling up and dying. 
The plants were flowering now and setting pods. The worse affected plants started dropping their leaves. I needed to look harder at them to determine the problem. I was still suspecting the soil. 

Searching the Internet photos, I saw bean leaves that looked somewhat like mine. Spider mite was the diagnosis. So I went out a looked under the leaves of my plants. Even took sticky tape to try to capture some mites in order to identify them. Nothing. No mites. But I did notice that some annoying little black things, like dog fleas kept hopping around, tickling my arms. Hummm. Could they be a pest? 

Searching the Internet again, I came up with pictures of flea beetles. So I went back to the garden to look closer. Now that I knew what I was looking for I was stunned to find a whole city, I mean a giant city network like NYC of flea beetles! Those holes on the beet leaves --- flea beetles. 

The stunted chard --- flea beetles. 

This is what unaffected young chard looked like.....

The dying beans --- flea beetles. 

The dang beetles had started moving out to the suburbs and were now taking up residence on the potatoes and sweet potatoes. Wow. All I could think was, "Good thing I spread my gardens around so that everything on the farm isn't infested." 

Ok, back to the Internet. What can I do about ridding the garden of flea beetles. I don't have a minor problem, I have a pan epidemic. I found all sorts of advice, from knocking the beetles off the plants to spraying with permethrin. I figured I'd try the non-chemical approach first. I'd knock the bugs off and capture them.

 So I devised a trap board. I took a piece of cardboard and coated it with something that would be sticky enough to capture the beetles when they jumped onto it. Cooking oil seemed like a good idea. 
So I marched out to the bean plants with cardboard trap in hand. I slipped the cardboard under a plant, gave the plant a good rap, then checked my trap. Wow, coated with bugs! 

I definitely had more beetles than hand plucking was going to handle. So I broke out the insecticidal soap spray and doused the plants, top and bottom. Okay-dokey, looks good. 

Next morning I made another cardboard oil trap to check my progress. Oh my, hundreds of new beetles. An hour later I checked again. Hundreds of beetles. At lunchtime I once again checked using my oil trap. Once again, hundreds of beetles. They were hatching out.....or moving into the neighborhood....faster than I could deal with. Or another possibility, the soap wasn't affecting them. Back to the drawing board. 

I decided that I'd use the beans, potatoes, and sweets just for seed. Thus I would bring out the big guns and spray with Sevin. That surely would kill the beetles, letting me determine if I was dealing with adults the liked to bathe in soap or newly hatched beetles. For two days in arow I applied Sevin. Checking one hour after spraying I saw zero beetles. But the next morning the plants were again coated. So I sprayed. By day three the beetles were just as bad. Ok then. I'm dealing with new hatchlings. The ground is infested. 

Out come all the plants. Yup. Yanked the entire crop. Stuffed everything into plastic trash bags, sealed them shut, threw them into the back of the truck for the dump. I don't often resort to this but I have to get rid of these bugs. Once the surface of the beds were clean, no plants, no dead or dying leaves, I flipped the soil. 

Next on the agenda will be to determine which crops I can plant here that are not affected by flea beetles. I'll grow them for a cycle or two before trying beans again. 

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