How interesting guys...can't wait to hear about the results and to see pictures...

Seems I failed to post the link for the Pediobius foveolatus supplier. Here it is.

Jim

Here is a link that might be useful: Pediobius foveolatus from Biconet

Here's the pictures of the wasp.

Sorry that was a 2lb Reif red heart
lets try again

Getting closer that's two 2lb Reif red heart and the Pediobius foveolatus in the cups
and there goes $80 dollars into the wind.

Actually they only attack the Mexican Bean Beetle so they will scourer the beans looking for a host. The wasp are smaller than a fruit fky about the size of a gnat. The are shipped in the cocoons made of the larvae of the MBB and hatch out in transit ready to mate and lay eggs on the MBB larvea. I put the cup in the beans and leave it they will all fly out and go to work in a weeks time you can find the MBB larvae turning brown and if you opened one up it will be full of tiny maggots feeding.

and without the MBB destroying the beans I can finally pick a batch of beans with no holes in them.
{{gwi:107999}}
Rodger

Your pictures do a good job of showing what you receive in an order of P.f. (not the first picture, LOL, the others). I would never recognize them as wasps. They are tinier than any no-see-ums I have ever seen (or not seen). What you get looks like a couple of shakes of finely ground black pepper and about six crumbs of something indistinguishable in a little plastic medicine cup. I've never paid so much for so little. It's hard to imagine them having any effect when the go poof into the garden and disappear.

But the point is "you will be amazed at the results." That's what I'm counting on. With some luck, I might have the result you did, where the MBBs are knocked down so well by the end of summer that there are few to winter over and they won't be the scourge next year that they have been previously. I wondered if that might happen and I was happy you said it did for you.

One of the sites I read told of large-scale soy bean growers planting a small early crop of snap beans in order to have the wasps ready ahead of time for their soy bean crop. I'm thinking that, for us small scale bean growers, it might be good to start a few beans under cover, ahead of our regular crop, for the same purpose.

Jim

An interesting report which reinforces Rodger's experience:

"Last summer the wasp parasite Pediobius was released in the student gardens at the University of Wisconsin - Madison for control of Mexican bean beetle. The beetle had been a devastating pest on bean plants in these gardens for years some people even gave up growing beans entirely. Early this summer local gardeners reported they had yet to find any leaf damage or any beetle larvae or adults. They didn't want to be too optimistic, but were hoping that the wasp releases the year before completely eliminated this isolated population of Mexican bean beetle. A team of researchers searched the gardens in early August and were unable to find any beetles either."

Source:

Barrows, E. M. and M. E. Hooker. 1981. Parasitization of the Mexican bean beetle by Pediobius foveolatus

One week has passed since releasing the wasps. One week is supposed to be the time in which MBB larvae pupate and the parasites begin to grow within them. There are MANY MBB larvae attached to the bean leaves. I will try to post some photos tomorrow.

I am hoping I didn't start too late to achieve a good result. It is necessary to have MBB larvae in the bean patch ready for the wasps to parisitize when they are released. But there must not be more than the wasps can infect. There are a finite number of MBB generations in a season, fewer here than in the South. Of the four beans/peas I am growing only one, a bush wax bean, is heavily infested. I estimate that more than 50% of the foliage has been destroyed. I am willing to sacrifice this crop to the experiment.

Jim

Glad you guys have found something that works against those MBBs. I grew up battling them every year in Tennessee so I'm well aware of the damage they can cause to beans.

Luckily I haven't seen a single MBB since my move to Alabama which was over 8 years ago. (knock on wood)

If at some point they do show up I'll try your little wasps but I hope I never need them.

My beans have done surprisedly well this year dispite the drought. We've finally started getting some rain, just in time to rot the drying seed beans.

Here is the essence of this thread in two concise paragraphs:

"Pediobius foveolatus has been used for biological control of Mexican bean beetles in soybeans on a county-wide scale for the last 20 years in Maryland and New Jersey. Pediobius foveolatus is a tiny wasp -- 3 mm. or about 1/9 of an inch in length -- that is a parasitoid of Mexican bean beetle larvae and squash beetle larvae. (A parasitoid is a parasite that kills its host.)

This wasp does not survive the winter in the U.S., and thus will be present only if you buy wasps from a laboratory colony and release them. An adult female wasp lays about 20 of her eggs per Mexican bean beetle larva (2nd to 4th molt). The wasp eggs hatch inside the Mexican bean beetle larva and feed on it, eventually killing it. About ten days after the eggs are laid, the body of the Mexican bean beetle larva becomes a "mummy," with the outer skin darkened, but intact, while the wasp larvae inside develop and form pupae. When the wasps emerge as adults (about seven days after formation of the mummy), they break a small hole in the skin of the mummy and climb out. They mate, and fly off to feed at flowers and find more hosts. The females gradually lose their egg-laying capacity after 3-4 weeks. They can travel several miles over one growing season."

Jim

Here is a link that might be useful: Full Text

Jim, check your plants good, you should see paratised larvae, I found this today.
Top is a larvae still alive, but invested and almost dead
Middle is a fully cocooned larvae new wasps will hatch in a couple of days
lower is a live and well MBB larvea, but not for long when the hundreds of new wasps hatch from the middle cocoon

Jim when you find the brown MBB larvea pick one off and place in the container yours came in then set it in the house in a few days it will be full of baby wasps then release them or give them to someone else with beans. I gave dozens of cocoons away last year to locals. Rodger

You've been reading my mind, Rodger. Everything you said addressed something I've been pondering and wondering about.

Your picture shows me exactly what to look for when I go out to the garden a few minutes from now. I will surely keep one of those mummies in captivity to watch.

Jim

OK. Right on schedule, 10 days after releasing the wasps, I have a brown larva in my bug jar and the bean patch has many more.

One thing that has bugged me (sorry about that) ever since I received the wasps is that they looked smaller than described in the articles. The article quoted above says they are 3mm or about 1/9 of an inch. Mine appeared much smaller, although I didn't try to measure them. My eyesight is not so good any more but I couldn't even distinquish their waspish shape. Next time I will use a magnifier.

How large do they look to you, Rodger? I saw little black dots moving about in the container I recieved, so I am going on faith that I have actually innoculated my beans with Pb.

Jim

I'm hoping that mine will arrive tomorrow. I bought them on wednesday, but apparently they don't ship till tuesday. This ought to help quell my annual bean beetle damage.

Incredible! Like clockwork, the wasps are emerging this very day from the mummy in my bug jar, just as Rodger said they would. None had emerged earlier in the day. Now there are many, right on schedule.

This means that hundreds are emerging from the mummies initiated when the first batch was released 10 days ago in the garden. This will result in thousands in the next generation, 17 days from now and beyond. It is fun to visualize what is happening throughout the garden, which is not visible except for the appearance of mummies.

If I understand correctly, the wasps deposit eggs in the beetle larvae over a span of several days, so the results will spread over time with each generation.

Jim

How long till the numbers of MBB get really affected? I have a big infestation. I may lose the fall crop if things don't change quick. Lots of leaves are just lace now. I am squishing them daily but there are thousands of them and only one of me. I do have a day job dontchaknow. I have 4 packs of wasps on order. I sure hope they are in stock and ready to ship. So again how long have you seen in your gardens to see a drop in mbb numbers? Plantnfool

Rodger can give you a better answer than I can, since he is well into his second year of using Pb.

I released mine exactly a month ago. I had been waiting for a fair number of MBB larvae to be present. I may have waited too long because the beetles have been increasing, not decreasing since then. The bush wax beans, which were most attractive to the beetles, are now 100% lace. The beetles have moved on to the pole beans, although not in such large numbers.

Of course, it probably takes more than a month to build up the population of wasps. The first generation takes 17 days to emerge. So I can't expect to see the second generation emerging until Thursday. Since the wasps live for several days, each generation should be spread out over more time.

My hope is that, like Rodger, I will see a large decrease in MBB next year. It would be nice to see some results yet this year though.

Jim

Hmm......... A month before any decrease in numbers? The fall bean crop may be history. We will keep squashing them and hope for the best. Jimster how many containers of the wasps did you release in how much garden? I have 4 packages on order as I have said for about 75 feet of double row beans plus 3 4x4 patches of bush beans. Some of these are heirloom varieties that really need to make me some beans for next year's seed. Hopeful yet. Plantnfool

Thursday came and went with no evidence of the large emergence of wasps I had hoped for. That doesn't mean it didn't happen, it just means that nothing happened in my bug jar. In the field it is difficult to monitor what the Pbs are doing. All you can observe are the mummies. I did find mummies here and there.

I have only 20 feet of wide rows and seven poles. This is in a community garden however, and I am surrounded by many plantings of beans. I released two units of Pb. One of those appeared defective, so the total effect may not have been optimal. Also, as I said before, my timing may not have been good. Nevertheless, the first generation seemed to happen as expected and I am hopeful of getting a noticable result by next year.

Let's hear from everyone who is using the wasps. What are your observations?

Jim

Plantnfool, timing is everything for the PF. The website states to release as soon as larvae are present and that it will take a few weeks for the wasp population to then exceed the larvae. Last year I released the wasp in late may. I had about 50% defoliation on the beans by late june but plenty of cocoons. I never had any damage on the Limas or peas for the remainder of the year and by end of July I could find no trace of any beetles. This year I had to post pone the wasp three times and I finally had beetles first week in July and recieved the wasp on the 13th of july. This year has been odd. I had maybe 10% defoiliation on the beans they finally died out due to the 2weeks of 100 plus days we had. I am still seeing beetles on the limas this year and none on the peas. I have no appreciable damage on the limas so there is still wasp but I continue to see beetles but very few if any larvae. I am suspecting with the drought we are having that the famers have giving up on the soybean crop and have not sprayed. So there is a overload of beetles searching for food and they have found my irrigated garden. But if everything works out the wasp should prevent and future generations. I will have to continue to monitor and see how the rest of the year goes.
Rodger

Question...how does the life cycle of this beetle work? If I kill larvae this year will it keep MBB's from maturing this year or cut down on the larvae that will develop into MBB next year? Reason I am asking is that they plagued me last year starting with first true leaves on the beans...was a constant battle all summer. Even though I left larvae on bean vines I piled on beds to overwinter...this year they are just now showing up. We did have a late hard freeze last spring...that may be the reason...don't know.

And they worked like a charm. This was the first year I can remember when the beetles did not eventually win and devour all of our bean vines. They were still fairly lush at the end of the growing season here in NORVA. The investment was worth it. Definitely going to get them next year if I see any signs that the beetles survived in some other corner of my garden.

I wonder if you could save a few MBB and maybe a single plant in a garage. Maybe then you could feed the wasps over the winter?

kind of late to do so around here. I think a larger setup would be neded in any case then a simple garage. You need a room to grow just beans and beetle larvae, or you kill off the wasps' food source like they did in my garden. Then you need a room where the wasps can eat all they want.

I envision two separate greenhouse enclosures just to be on the safe side. Both of them with bush beans since pole beans would be a "stretch" to grow in a VA winter. House "A" would be for raising wasps and would receive a weekly or twice a week supply of hand picked larvae from house "B". House B would have bean beetle larvae and bean plants, and we would need to be careful to keep wasps out of it. Ironicly it would be a case where if you found a parasitized mummy it would be the insect pest and have to be removed.

Then, come spring this could be the source to re-parisitize a garden and send off mummies. Kind of expensive though and I'd hate to risk re-introducing bean beetles if I had successfully gotten rid of them.

Rodger, if you are reading this, please give us an update on your trials of Pediobius foveolatus. Did you need a follow-up treatment this year or was the MBB population sufficiently knocked down by last year's treatment?

I've seen few MBB this year but the season for them is just beginning I believe. Beans here are just beginning to set pods.

Jim

Earlier in this thread I told about my experience with Pediobius foveolatus last year. At the end of the season I didn't know if they had been effective and I still don't for sure. Last year was a bad one here for MBB. I had hoped I could get the results that Rodger did where the MBB population was decimated to the point they were not a problem the next year.

As of today, I have seen only the occasion beetle. The beetles I am seeing are a different color from last year's, which makes me wonder if they are new invaders and the ones we had last year were wiped out. BTW, there is color variation in MBB.

Bush beans are starting to set pods. Today I inspected plants until I got bored with it and found no beetles, eggs or larva. Leaves have a few holes but nothing resembling the devastation last year.

It was July 13 last year when I wrote, "The beans are growing lushly and are supporting a bumper crop of Mexican Bean Beetles."

I'll keep watching. So far so good.

Jim

Jim, I noticed the first beetles last week then on Friday I saw some larvea feeding. It was only on the Zelma Zesta and only in a spot about mid way. I went ahead and ordered the wasp, better safe than sorry and I do not want to develope a resident population again. It seems Mid July is when the MBB arrive. Before I started with the wasp I would have then in droves by mid May and by the time the early beans made the first crop the plants were about defoliated. Then they start on the limas followed by the peas. Rodger

On July 15, 2008 Jimster wrote:

"It was July 13 last year when I wrote, "The beans are growing lushly and are supporting a bumper crop of Mexican Bean Beetles."

I'll keep watching. So far so good.

Well Jim, how did things turn out last year? I'm jumping into beans a little more this year and I'm wondering if this might be worth looking into. I'm really interested in your experience / opinion.

Thanks -- Rick

jimster
This wasp does not survive the winter in the U.S.

I see some discussion about trying to overwinter them as well as a couple of statements that all the MBB were probably destroyed since none showed up the next year.

My question is more about the MBB than the wasp, though they are related.

Where do the MBB come from? Do they overwinter in the soil or do they fly in from elsewhere? If they overwinter in the soil, I can see how a summer release of the wasps just might destroy most or enough of them so there weren't any the next year. But if the beetles fly in from elsewhere, wouldn't you need to release the wasps yearly?

I am SO glad you guys are testing the efficacy of these wasps and refining the timing of their release. It's a very expensive way to conduct careless tests!

I haven't had problems with the MBB, but sure have had an embarrassment of cuke beetles. Too bad they can't both be controlled the same way, but they can't.

I'll be curious to see if anyone who released the wasps last summer and saw them active has problems with MBB this summer.

Anney, both statements are correct on the MBB. They overwinter in the ground and emerge about this time of year for us in the south. They also migrate in from other areas. So before I started using the Wasp I would have MBB chewing on the beans about two weeks after they sprouted. Now I no longer have any resident MBB population thanks to the wasp but I do get migrating MBB around early to mid July which have little effect on my greenbean crop since it is about over but they would destroy the Butterbeans and southern peas if I didn't release new wasp each season.

This thread has been great reading and learning. I wish there was a similar solution for my worse pest problem (Harlequin beetles AKA Murgantia histrionica). Happy that I do not seem to have this infamous MBB (knock on wood) but I had a question about another strategy. In her book "Great Garden Companions", Sally Cunningham advices to interplant beans and potatoes. She claims this will deter both the Mexican bean beetle and the Colorado potato beetle. Has anyone tried this? does it work? I am inter planting beans and potatoes myself, but my reason is more to use the shade from the pole beans (Garafal oro and they are jumping out of the ground!) to cool the potatoes since last year the heat did a number on the potatoes (too much heat interferes with tuber formation it seems). However, I do want to keep both types of beetles away too. Any experience with this approach?

My experience with P. foveolatus over two summers confirms everything posted by Rodger, from whom I learned it (thanks Rodger). Last year, the year following release of the wasps, no MBBs whatsoever were seen. That was better than expected, to say the least. The resident population must have been decimated. I will be watching carefully this year because, sooner or later, there will be a new invasion.

Thank you Anney, for your work on control of cucumber beetles. Those who haven't read her posts should search them out on the Vegetable Forum. It's valuable information.

Jim

rodger

So that statement about their not being "over-winterable" is pertinent in only the northern states. That's very good to know. Less encouraging is their ability to migrate later in the season! I'll keep a lookout for the MBB. I did see a pink lady-buggish looking beetle last summer, but I think it was one of the good guys roaming pretty far east. None of my bean plants were damaged by insects.

jimster

Well, even if we weren't the originators, we can take the research and claims of others and at least test them to see if they hold up and also learn the best ways to apply the principles, right?

If you're lucky, you won't have to deal with a second wave of migrating MBB like rodger says come to do in his limas and Southern peas. I hope you stay beetle-free!

I know it's only May, but please keep this thread alive with at least occasional updates since the beetle activity is probably just getting started in some places.

On Tue, May 5, 09 Jimster said:

"The resident population must have been decimated. I will be watching carefully this year because, sooner or later, there will be a new invasion."

It's about that time Jim - how goes it with the MBB?

How about you Rodger, are they still in check?

They started showing up here last week and it's not a pretty sight 8^(

I guess if I'm gonna grow beans, I'm going to have to address this issue somehow.

Thanks -- Rick

Mine showed up Mid June this year earlier than usual. I ordered the wasp for delivey the following Tuesday but it was a bad hatch so it was re ordered for the next week but that one was lost by fedex. Finally three weeks late I recieved my wasp. So I have a fair amount of dammage but I see lots of mummies so they are doing the job. This is the first time having so much trouble with an order of the wasp . I hope I dont have a repeat next year. Rodger

I haven't seen a Mexican Bean Beetle yet this year, plenty of pests on other crops but the beans are clean as a whistle, no leaves chewed at all.

Jim

Back in 2007, Rodger said "Jim, you will be amazed at the results."

I was and I am. Another year has passed with no sign of a Mexican Bean Beetle. Plenty of Colorado Potato Beetles and Tomato Fruit Worms but not one MBB. The P. foveolatus must have done a thorough job of exterminating them in 2007. Apparently the release of the wasps was well timed. I expected a few MBBs to return by now but none have. Maybe that is because there are no other vegetable gardens near ours.

Jim

I don't know how I missed this thread. Clearly, for large growers like Rodger or bigger market growers, the wasp is well worth the money.

Rodger, if you read this, can you speak to the attractiveness of cowpeas to MBB?

This was a terrible year for beans due to the heat. Worse crop ever. Less than half the yield on heat tolerant varieties and no production on many of the other varieties. On the MBB they showed up right on time first part of July but the wasp I released in July have keep them at bay and no damage, but I am still seeing mummies and beetles in Sept on the peas and limas runners and hyacinth beans. My experience has been they prefer common beans when these are gone they go to runners. hyacinth and limas when these are done they show up on peas. This is also the order in which the various beans are planted and harvested but I have and do grow limas, common beans, and field peas side by side planted at the same time and the preference is still for the common beans then when the common beans are done and removed end of July the MBB shows up on the Limas first then they start showing on the Field peas but in lesser quantities. Rodger

Well, it has been quite a while but Jim reminded me to come back and read Rodger's answer to my question of over a year ago. Thanks for the reply, Rodger and my experience last year confirmed that MBB is not fond of Vigna.

I would like to think that I do not need the wasp in my gardens but it could be useful to others in this area who deal with the pest on much larger scale.

Ha! I had forgotten your post re Vigna and MBB, Pat. I was thinking only of Pf wasps when I called your attention to it. Anyway, it worked out well, given Rodger's info on that subject.

It's true that the wasp is an uneconomical way to deal with MBB in a small garden. It takes a lot of beans to make up for the cost. But think of the benefit which would accrue if you could rid your whole island of MBB once and for all, just as St. Patrick rid Ireland of snakes

Jim

Indeed, a great benefit, Jim.

I am not quite clear: does this wasp not establish itself permanently once released? it must be re-purchased? This would seem to be a significant deficit to its usefulness in our war with MBB since MBB is quite able to overwinter.

The wasp does not overwinter in the North. But Rodger's experience and mine has been that the resident population of MBB can be wiped out. One application of wasps was made in my community garden in 2007. There has been no reappearance of MBB and no further applications have been necessary.

Jim

The wasp does not overwinter in the North. But Rodger's experience and mine has been that the resident population of MBB can be wiped out.

One application of wasps was made in my community garden in 2007. There has been no reappearance of MBB and no further applications have been necessary. It may not always be quite so successful because MBB can move back in from neighboring fields.

Jim

Dang double posts.

I have been following this thread with great interest since I'm a member of a community garden in Geoergia that is overrun with Mexican bean beetles. Inspired by your experience, we bought some Pediobius foveolaus which arrived July 3 as mummies, put into the garden July 4 (it was over 100 degrees for several days then, hope that didn'dt hurt). We've seen just a few new mummies since then, and have instructed fellow gardeners not to squish larvae since they could have wasp eggs inside. When anyone pulls up a devastated bean plant we pick off the MBB larvae and I'm currently saving them in jars in my house (only 3 are currently mummies,the rest we're watching for browning. Several have already molted into adults).

So here's my questions: should I just return these mummies to the garden? Or are they delicate and should be held somewhere besides the wilds of a garden until they hatch out? When should we expect a hatch, 17 days or so from July 4?

We're only hoping for a knockdown of a big MBB population, hope to start over next spring at the proper time. Any advice would be welcome!

"...should I just return these mummies to the garden? Or are they delicate and should be held somewhere besides the wilds of a garden until they hatch out?"

I would just return them to the garden. But I think Rodger kept them inside until they started hatching. You could do some of each.

"When should we expect a hatch, 17 days or so from July 4?"

Yes. Seventeen days or so. However, the eggs are deposited over a period of a few days. So, the timing will become more varied with each generation.

Jim

You can leave them in the house, I do it a lot it's kinda fun to see then hatch out. I am always taking some mummies then put them in a jar and when they hatch out I give them to neighbors to help rid the area of MBB. I still get the MBB every year so I have to reorder each year. This is a tropical wasp originally from India. I have not seen any evidence of it over wintering for me. What I have been told is the wasp is not active when temps are less than 50 and below 40 can be lethal. Rodger

Thanks Rodger and Jim for the input. I was kinda worried the adult wasps might die in the jar before I noticed they had hatched - they're so tiny in the pix I've seen. Plus don't really know how many days it took for the purchased mummies to hatch, mate,and lay eggs after we put them in the garden on July 4.

Will report back later in the season after we've had time for a few generations to hatch out. Now we have to deal with the new kudzu bug invasion.

Carolina

Another year with not a MBB to be seen. The application of P. foveolatus back in 2007 has paid off big time. I know it is not effective as that everywhere but, in our situation, the result has been incredible. The garden just does not get reinfected.

Jim

Now that I am embarked on producing large amounts of dry beans I may consider doing this next year.

I probably will have enough beans this winter but only barely. MBB came in hard late, so will probably be a big problem next year unless I largely abandon Phaseolus in favor of cowpeas, which I'd rather not do.

Last summer with guidance from rodger and jim I released the P.v. in our community garden, too late for control but mainly to become familiar with the process. It took awhile but their population rose all summer as the bean beetles dropped to nearly nothing. Of course by then the bean crops were toast so we couldn't monitor the effect on beans. Did notice squash beetle adults with the Mexican bean beetles gone, sure do hope the P.v. will infect their larvae too, does anybody know that? The whole process was actually fun! Am looking forward to starting this season at the correct time with a new release of wasps, I just have to assume there will still be some MBB lurking around.

Carolina