Return to the Oklahoma Gardening Forum | Post a Follow-Up

 o
colorado potato beetle larva

Posted by borderokie none (My Page) on
Tue, Jun 4, 13 at 23:19

I have been trying to figure out what these bugs are on my tomato plants. Never have seen them on tomatoes before. Finally found them and they are the potato beetle larva.. any suggestions for ways to kill them wihout poison besides sqashing them. That is getting a little hard to keep up with every day. Sheila


Follow-Up Postings:

 o
RE: colorado potato beetle larva

I just put on disposable latex gloves. Then, holding a bowl of soapy water in one hand, I either pick them up and drop them into the bowl of soapy water or flick them into it and they drown. We had a major outbreak of them about 10 days ago and for a couple of days I spent a huge amount of time walking up and down the rows of potatoes and finding them all and killing them. I have found only three since then so think I pretty much got them all. This is the least toxic method since only the potato beetles are harmed. You can buy an organic product called Colorado Potato Beater and spray the plants with it. The active ingredient in Colorado Potato Beater is Spinosad. I have a bottle of it but would use it only as a last resort since it is toxic to some beneficial insects. There also are some other organic products for Colorado Potato Beetles that contain Bt but they are not easy to find, especially at this time of the year.


 o
RE: colorado potato beetle larva

Thanks Dawn. I will keep trying, my problem is time. Too many jobs not enough me. Like droppimg them in soapy water better than smooshing them. Not squeemish but they kinda go everywhere sometimes. (On me) those are the ones that have definiteyly been on there too long. nice and fat!!!


 o
RE: colorado potato beetle larva

I am not sure footed or coordinated enough to do a good job getting the bugs. I was wondering if minnow bucket dip net might work at capturing the adults, they often fall off the plant before I can get hold of them?


 o
RE: colorado potato beetle larva

borderokie, Unfortunately for those of us who try to raise our gardens as pesticide-free as possible, the alternate methods that we employ instead of spraying pesticides are, indeed, extremely time-consuming. What I have found is that if I can manage to find the time to hand-pick and destroy the beetles when the outbreak first begins, then I will have little to no trouble with them after that. Thus, I might have spent a ridiculous amount of time over the course of a few days hand-picking and drowning the beetles, but I haven't found many since then--maybe 3 or 4.

What I have noticed the last few days is that the spined soldier bugs have shown up and now are sitting on top of the potato leaves. They will provide CPB control for me for the remainder of the summer, so my work is done. An alternate method of doing this if your garden doesn't have a naturally-occurring population of spined soldier bugs is to buy some from an insectary and release them.

We also have two turtles crawling around in the garden who like to eat CPBs when they can find them, but the turtles are more effective when the plants are smaller and the beetles are down low within their reach. With all the recent rainfall, the potato plants are very tall now and the turtles cannot reach the bugs that are higher up on the plants.

For a long time, we could use Colorado Potato Beater's old formulation (and other products with the same active ingredient), which at the time contained a bioinsecticide called Bacillus thuringiensis 'san diego' or 'tenibrionsis'. Unfortunately, those products have become harder to find. Bonide, which makes and sells Colorado Potato Beater changed their product's formulation from the Bt strains to Spinosad. I assume they did this because repeated spraying of the Bt product was leading to Bt-resistant CPBs. History has shown that CPBs develop resistance to or tolerance of commonly-used insecticides so you have to rotate the products you use in order to prevent that from occurring, or to at least slow it down.

You still might be able to find one of the Bt products that target CPBs at a farm store or someplace with a great selection of organic pesticides, but all the stores here near me merely carry Bonide's spinosad product. Be sure you find the particular strain of Bt that targets CPBs, because there are other strains available that target other insects, like Bt 'kurstaki' for caterpillars or Bt 'israelensis' for mosquito larvaw.

Pyrethrin sprays often work on CPBs too, but they are more toxic to other life forms and I don't want to use them in my garden, especially the formulations that contain PBO. We have cats that spend a lot of their time in the garden with me and pyrethrins can cause nervous system disorders in cats, so I don't use pyrethrins often, and generally only as a last resort. Sometimes I'll spray Take-down Spray directly on a pest, like blister beetles, in the garden, but not when the cats are in the garden with me, and never on a plant the cats adore like catmint, catnip or cat grass.

Larry, You could try the net and see if it works. CPBs are smart and do seem to 'dive' off the plants when they see us reaching for them. To get around that, i hold the bowl of soapy water under the leaf with my left hand and then reach for the CPB with my right hand. If the CPB sees my hand approaching and attempts to jump or fall off the leave to get away, it falls right into the bowl of soapy water. Isn't that helpful? I appreciate that those CPBs put themselves right into the bowl of soapy water for me.

Dawn


 o
RE: colorado potato beetle larva

Well I went out to hoe without a bowl of water and ended up squishing what I think is the last of them. ( I swear I have old age A.D.D.) But I am sure when I go back out tomorrow I will find them miraculously on my tomatoes munching again. Sheila


 o
RE: colorado potato beetle larva

I have had none on my tomatoes but if you have eggplants check there- I had at least one egg cluster on every single plant (only four plants) today.


 o
RE: colorado potato beetle larva

You also can find them on other plants in the solanacea family, like petunias, daturas, nicotianas and peppers. Usually I find them most often on potatoes. I've only rarely had them on the other plants, but last year they couldn't find the potatoes, which had been rotated to a distant area, so they got on the tomato plants one row over from where the potatoes had grown the previous year.

I haven't seen any at all this week, so maybe I've found and destroyed all the stragglers that hatched out after my big potato bug seek-and-destroy mission a couple of weeks ago.


 o
RE: colorado potato beetle larva

I found a couple dozen of those beetles on three of my taters, today. Picked quite a few - most of 'em, I think. Gonna try some dish soap and water on them tomorrow. Just to make sure. As long as they're still in the larva stage it should hurt them a bit.

Mostly, the only reason I don't jump for the chemicals is to keep expenses down a bit. I prefer organic means and methods, but I'm not afraid to nuke 'em from orbit, if that's what it takes. Plus, trying to pick bugs off ninety taters gets real old, real fast. The other factor is that I like to go out in the garden and 'graze' from time to time. If I gotta stop and wash the chems off, first, it defeats the whole point. Plus, those little 'taste tests' lemme know how things are going wrt health and nutrients and water and such.


 o
RE: colorado potato beetle larva

I'm glad I searched for "Colorado potato beetle control okiedawn" since I'm dealing with CPBs now. I am growing potatoes in two gardens - the kitchen garden close to the house, and the "big garden" a few hundred feet from the house where I do surveillance less often. I didn't realize that the potato beetles had arrived in the big garden until they did a fair amount of damage. Spent hours handpicking for a few days. That reduced the population but I am still finding lots of small ones so I squish them or put them in a jug of soapy water.

I do have a question. The plants that were hit the hardest are still infested with tiny beetles. What's left of the leaves have smudges of what looks like blackish powder. I assume this is related to the CPBs. I thought about cutting off the damaged leaves but decided to wait until I could get advice from the experts. ;-)

Haven't seen spined soldier bugs but didn't realize they had an important role to play. Have seen a few blister beetles. Good images of the blister beetles show bugs with very different markings. Had a close personal experience with a blister beetle last year - no fun!

Is there anything else I should be doing?

Thanks!
Pam


 o
RE: colorado potato beetle larva

wbonesteel, I've never broadcast sprayed a synthetic pesticide in my garden (or anywhere else on our 14.4 acrs) since moving here because I like to graze too. I did spray everything with Bt 'kurstaki' last year because of the massive amount of climbing cutworms. That's the only time I've ever sprayed the whole garden with anything, even any organic thing. I just hate spraying period and won't hardly do it even with organic stuff. I don't even like spraying with spinosad, which is organic, because it harms some beneficial insects, especially bees. If I have to use it, I spray it directly on the pest I want to kill---not even on the whole plant the pest is on, just on the specific leaf. I'm a pretty die-hard anti-pesticide person, except I use EcoBran for grasshoppers. Some years we have grasshoppers here at numbers as high as 10-15 per square yard. High hopper numbers are a perpetual problem in a rangeland area, which is where we live. One year they were so bad the ranchers sprayed like mad to try to save their rangeland, and the result was that all the bluebirds disappeared and most of the grasshoppers did not. I expect the birds died after ingesting pests sprayed with a strong pesticide. It took our bluebird population 3 years to start coming back, and 10 years later, I still don't see as many now as we had before that. This partly lmy strong adversion to pesticides....they hurt so much more than the pests. If I wanted to eat food heavily sprayed with pesticides, fungicides and lots of synthetic fertilizer, I'd just buy grocery store food instead of going to all the trouble to grow our own produce.

I have about 400 potato plants so hand-picking the CPBs was an enormous PITA but it paid off because I've only had a few since then, and I quickly hand picked and destroyed them. My plants are just starting to look ratty, mostly on the early varieties, so I expect the vines are preparing to die down in advance of the harvest. I still don't think I'll be harvesting for several weeks though, unless I planted them earlier than I think I did.

Hi Pam, By tiny beetles, do you mean newly hatched CPBs or potato flea beetles?

Tiny smudges of blackish powder could be several things. Could be black mold, beetle frass or something else. Also, Late Blight sometimes looks like black powder on foliage in its earliest stages----don't panic because it likely isn't that but I'd be remiss if I didn't mention it.

Spined soldier bugs are so wonderful. I treasure them. They will roam the garden and eat all kinds of pests. I found one on a lawn chair yesterday and asked him what he thought he'd find there! He just skittered away sideways and tried to hide from me---as if I would ever harm a beneficial insect.

I have blister beetles in varying numbers every year. To the extent that I can, I leave them alone and let them be. They eat grasshopper eggs, so in most instances, I like to keep them around since grasshoppers are almost always an issue here. If I find them eating on cucumber leaves or tomato leaves, I usually grab the garden scissors from my garden tool bucket and snip them in half. Then I take a Chlorox wipe and wipe off the blades of the scissors. This explains the canister of wet wipes in the tool bucket.....I am not an obsessive clean freak, but I hate to have blister beetle guts and goo on my scissors. Some people hand pick blister beetles, but I won't touch them, not even with gloves on.

Dawn


 o
RE: colorado potato beetle larva

Sorry, I'm a little late on this post but I'm in the middle of CPB hell. They are devouring my flowering nicotiana and petunias & my tomato plants are a mere 20 feet away. I go out early in the morning to catch the little buggers because they're much slower that time of day. I've also used my vacuum cleaner on them, which makes it a wee bit faster than hand picking. I squish all the little orange eggs I can find. Yesterday i got fed up and just pulled all the nicotiana out and soaked it in hot, soapy water. Not a great option for veggie growers but I was becoming obsessed.


 o
RE: colorado potato beetle larva

Katie - you have my sympathy. I didn't know about CPB until this year (first year to grow potatoes). I handpicked, dumped them in soapy water, and squished them for weeks. I thought I made a big dent in the population but a few days later, the plants were full of them again. I finally dug up the potatoes - tiny crop of small potatoes.

I think several factors combined to make this year such a nightmare. We had a very wet spring so I planted potatoes several weeks later than usual - just in time for the CPBs to hatch. Next year, if I can't plant seed potatoes in March, I may pass on planting potatoes altogether.

Take care and try to stay cool!
Pam


 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!


Return to the Oklahoma Gardening Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.


Learn more about in-text links on this page here