Ways to Control Mexican Bean Beetle

The Mexican bean beetle is one of the most destructive pests of the bean plant in the eastern United States and parts of the southwest, this garden insect pest is native to Mexico and belongs to the family Coccinellidae which includes the lady beetle that is a beneficial insect but unlike their family, the lady beetle the Mexican bean beetle as the names say does damage by feeding on bean plants where they cause server destruction.

Some plants that the Mexcian bean beetle uses as a food source are lentils, lima beans, peas, soybeans, snap beans, and runner beans. If You’re having issues with the Mexican bean beetle, here is what you need to know to bring complete control.

Mexican Bean Beetle Identification

The adult beetle is oval-shaped, about 0.31″ long and 0.23″ wide at maturity, and orange to copper with 8 black spots on each wing. The larvae of the Mexican bean beetle are yellow, possess soft oval-shaped bodies, and are covered with six rows of dark, branched spines.

Signs or symptoms of the Mexcian Bean Beetle

• Bright yellow eggs are laid on the leaves undersides in clusters of about 40 to 60.
• Larvae can also be seen feeding.
• The mature larvae at the pupae stage are yellow to orange in color.
• The adult and their larvae can be found feeding on the leaf’s undersides between the veins where the leaf’s lower epiderm is removed. The upper epidermis dies followed by producing a transparent, lacy appearance. Tissues that are damaged fall out, skeletonized leaves may curl and fall to the soil surface.

Mexican Bean Beetle Life Cycle

Overwintering Mexican bean beetles shelter under pine needles and leaf litter, in open fields, in wooden areas, and under plant debris. In spring, the adult beetles emerge and lay their eggs on the underside. Within two weeks, the larvae hatch and join their parents by feeding on the plant’s foliage.

Monitoring for the Mexcian Bean Beetle

• During early spring inspect the undersides of your garden plants for clusters of oval-shaped yellow eggs.
• Look for leaves that are wilted and discolored.
• If Mexcian bean beetles are present you will see both the adult and their larvae.
• The larvae that are yellow and spiny may be seen on the soil’s surface.
• Leaves that are skeletonized with the veins and midribs remaining intact.

Biological Control

Introducing beneficial insects into your garden can help manage Mexcian beetles and their larvae. Some beneficial insects include green lacewings, minute pirate bugs, ladybugs, stink bugs, assassin bugs, and damsel bugs.

Cultural Control of Mexcian Bean Beetles

• Remove all overwintering locations, such as leaf litter, bush, and weeds will expose beetles to freezing temperatures killing them.
• Small amounts of adult beetles and their eggs can be handed picked and thrown into a container with soapy water bringing elimination or eggs and adult beetles can be crushed.
• Planting early crops will help to prevent the second generation that emerges in midsummer.
• Cover your entire bean crops with floating row cover, the row cover can remain on bean crops until harvest time.
• Plants that are severely infested should be uprooted and placed in plastic bags and properly sealed, after about a week the plants and the beetle can be used as compost.

The Use of Insecticides to Control Mexcian Bean Beetles

Before using any insecticides read and follow the manfacture’s directions on the label for the best results.

• Neem oil can be applied to infected plants, once applied this oil will disrupt the Mexican bean beetles from being able to mate and feed. The application of neem oil also acts as a repellent.
• Other insecticides that can be used are pyrethrum or spinosad.
• Diatomaceous earth can be used to bring control, lightly and evenly sprinkle Diatomaceous earth over vegetable crops wherever insect pests are seen.
• The use of harvest guard can be used as a physical barrier to discourage the beetles and their larvae from feeding on plants.
•  Safer soap including insecticidal soap will control beetles and their larvae. When applying ensure to get both the top and the undersides of plant leaves.
• Sevin^® Insect Killer Ready to Use, Sevin^® Insect Killer Ready to Spray and Sevin^® Insect Killer Concentrate will bring control.

Conclusion

The Mexcian bean beetle can be controlled with the help of this guide, these beetles if left unmanaged can wipe out entire crops, so strike back by including these control measures. You will be happy with the results. Why should these beetles rob you of your harvest by destroying your crops?