Controlling Mexican Bean Beetle larvae - Ask Extension
Hello,
I have a community garden plot in Shelburne, and my bush green beans are infested with Mexican Bean beetle larvae. They are mostly on the unde...
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Controlling Mexican Bean Beetle larvae #877786
Asked July 18, 2024, 1:14 PM EDT
Hello,
I have a community garden plot in Shelburne, and my bush green beans are infested with Mexican Bean beetle larvae. They are mostly on the undersides of the leaves, which they have skeletonized. I noticed the first ones about 6 days ago, then went away for a few days, and they really exploded. Today I handpicked them off, and sprayed with neem oil and a little dish detergent. I'm hoping this will get them under control, but do you have any other advice? How often should I spray? And can this pest move to other plants? I have cucumbers, snap peas, and tomatoes in adjacent rows.
many thanks,
Kristin
Chittenden County Vermont
Expert Response
Hello Kristin:
Our apologies for not getting back to you sooner.
The following resource provides information on this beetle, including control methods - https://extension.umd.edu/resource/mexican-bean-beetle-vegetables/
Row covers are the recommended method for future infestations. Their preferred crop is Legumes, especially lima and snap beans. Also cowpea and soybean. Less preferred are fava bean, lentil, and mung bean. So, the rest of your plants should not be affected.
The most practical method to use in large plantings or community gardens is to purchase and release the beneficial wasp Pediobius faveolatus when larvae are first observed.
The Neem Oil you applied is also a recommended method.
I hope this information is helpful.
Our apologies for not getting back to you sooner.
The following resource provides information on this beetle, including control methods - https://extension.umd.edu/resource/mexican-bean-beetle-vegetables/
Row covers are the recommended method for future infestations. Their preferred crop is Legumes, especially lima and snap beans. Also cowpea and soybean. Less preferred are fava bean, lentil, and mung bean. So, the rest of your plants should not be affected.
The most practical method to use in large plantings or community gardens is to purchase and release the beneficial wasp Pediobius faveolatus when larvae are first observed.
The Neem Oil you applied is also a recommended method.
I hope this information is helpful.
Thank you!
