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FYI, a lure crop for Mexican Bean beetles

Posted by anney Georgia 8 (My Page) on
Mon, May 17, 10 at 9:12

Given the lure of radishes for flea beetles in my garden shown in this thread, I don't think the value of lure crops for insect pests can be overstated if the pests are destructive to your bean crops.

While flea beetles are too lively for hand dispatching (for me), the MBB is not, so if there's a patch where they all congregate leaving most everything else alone, they are definitely handleable.

I've been researching preferred host plants for Mexican Bean beetles, wondering whether soybeans are preferred over other bean plants by the MBB as was recommended on the Organic Gardening forum.

It would be great if someone would research or gather research already done on the preferences of Mexican Bean beetles in some sort of ranking, but all I could find was this link by the University of Florida that makes this claim:

It has been reported that some varietal
differences in leaf feeding damage from Mexican
bean beetle exist among common beans. Lima beans
are less preferred than snapbean. Among snapbeans,
the group called wax beans tends to be especially
. Other types of beans such as mung beans,
P. aureus, cowpea, Vigna sinensis, and soybeans,
Glycine max, do not escape Mexican bean beetle
damage; however, they are not preferred and are most
damaged when they are grown in the vicinity of snap
and lima beans, more preferred hosts.

If you like wax beans and grow them each year to eat, this won't be very helpful to you if you have to battle the MBB. But I don't like wax beans that much, finding them too bland for the time and effort that are put into growing them, so it's very useful for me! I'm going to sow some of the wax bean seeds I have left over from other years a bit away from my green beans and see if the MBB prefers them to the beans I want to save from their depredations! So far, I haven't seen any MBB among my green beans, but all the literature states they become active in this area just about this time of year, so I need to hop to it.

[Posted in case it's helpful for you, too.]

Follow-Up Postings:

RE: FYI, a lure crop for Mexican Bean beetles

  • Posted by anney Georgia 8 (My Page) on
    Wed, May 19, 10 at 4:49


Yours and Rodger's experience with Pediobius foveolatus needs to be included in the solution to any kind of MBB problem. As you said in another post, it may boil down to cost-effectiveness. Large crops of vulnerable beans are probably best addressed by the release of Pediobius foveolatus.

For smaller bean crops, I'm hoping to find a way to "herd" the MBBs into areas away from those crops where they can then be dispatched. I'll be planting a few wax beans several feet away from the Fortexes, Italian green beans, limas, and cowpeas and then see what I can do about killing the beetles if they gravitate to these wax beans.

RE: FYI, a lure crop for Mexican Bean beetles

I planted some bush beans last summer and no beetles. I did , however,
see the yellow beetles with black strips on my Love Lies Bleeding
plants. I think it was the bean beetle. Maybe Love Lies Bleeding can
be a trap crop.

RE: FYI, a lure crop for Mexican Bean beetles

  • Posted by anney Georgia 8 (My Page) on
    Sat, May 22, 10 at 6:33

If you mean this insect, it's a striped cucumber beetle. It prefers cucurbits, like cucumbers, squash, melons, etc.

This one is a mexican bean beetle. It looks like an orangish lady bug, sometimes pinkish, is a little larger than lady bugs and prefers to devour beans.

Neither are pests I want in my garden!

BTW, roper

  • Posted by anney Georgia 8 (My Page) on
    Sat, May 22, 10 at 6:52

Thanks for that information about Love Lies Bleeding -- I got sidetracked. I really love the old-fashioned version with the pendulous racemes, though I haven't grown it.

I'll keep it in my notes as another lure crop for cucumber beetles next year -- it's new to me. This year I'm using Caserta squash, a zucchini, reputed to be loved by cuke beetles, to see if I can get the beetles to devour the fruits infused with red dye #28, which kills them.

I don't know if my plan will work though, since I have all kinds of flowers intercropped in the garden this year, some said to repel or attract aphids, bean beetles, cucumber beetles, and the white icicle radish I KNOW will attract flea beetles.

Once again, thanks.

RE: FYI, a lure crop for Mexican Bean beetles

Yes, that's the beetle. Funny how they didn't bother my cucumbers.
I have not seen the mexican been beetle in my garden and hope I
never do. I took a picture of the Love Lies Bleeding. You cannot see
the beetles in this picture. There was not really a whole lot of them,
but this is the damage on leaves. The flower is very pretty, even gets
longer as the summer progresses. This is from last year.

RE: FYI, a lure crop for Mexican Bean beetles


I've been wondering lately if red dye #28 would be effective against other beetles, not just cucumber beetles. Why not? We would just need to find a way to get them to eat it.


RE: FYI, a lure crop for Mexican Bean beetles

  • Posted by anney Georgia 8 (My Page) on
    Sun, May 23, 10 at 6:41

Yes, I'd like to know that, too, particularly for Mexican BBs. The dye effectively kills Mediterranean fruit flies through its photoactive characteristics, too. Red dye #28 has been determined to be safe for human consumption for many decades. The dye is called a "light-activated insecticide", meaning that the insect must first ingest it and then be exposed to sunlight through the insect's transparent gut. The light excites molecules inside the insect, which is believed to cause a chemical reaction that kills the insect.

The trick for Mexican bean beetles would be to ID a lure or "feeding stimulant" to which the dye could be added so they'd ingest it, maybe some sort of "wax bean party cocktail"!

To continue about the medfly, in the US, a yellow dye is added to the red dye to make it more lethal to the flies:

SureDye works by ingestion and is composed of the red dye and D&C Yellow 7, 8. The yellow dye is added to the mixture to concentrate light inside a fly's transparent belly and thereby increase the transfer of light energy to the red dye. Chemically, the red dye is phloxine B and the yellow is uranine. They are similar in structure and members of the xanthene chemical group. SureDye is the product of PhotoDye International, a three-year-old company based in Linthicum, Maryland.

Scientists do not know exactly how this seemingly benign dye, used in lipsticks and edible drugs such as antacids, kills flies, but they do know that it must be ingested by a fly and that the satiated fly's gut must then be exposed to some level of light for it to have its toxic effect. Tests indicate that phototoxic dyes can be used selectively against fruit flies, since other organisms lack the transparent guts necessary for light to reach the dye.

It was found as early as 1928 that mosquito larva and some leaf miners could be killed through the absorption of photoactive dyes. Apparently, if mixed with sugar water it kills fire ants, too. Researchers in Hawaii are experimenting with developing lures and traps for the medflies.

Here is a link that might be useful: To Zap Medflies -- Red Dye, Updated Traps

RE: FYI, a lure crop for Mexican Bean beetles

"...other organisms lack the transparent guts necessary for light to reach the dye."

There's a clue as to which beetles it might work on.

This seems like a good subject for the amateur scientist.


RE: FYI, a lure crop for Mexican Bean beetles

Anney, did your plan with the wax beans work out?

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