Garden Sage: sophora plant bug

The sophora plant bug is relatively harmless, but can cause aesthetic damage to your flowers.

Q: I see these red bugs on the new growth of my Texas mountain laurel. It did not bloom last year and it was suggested that I am not watering enough. So I have been and now I have these guys. I don’t know if you can see in the picture but there is clear sap all around as well. I am thinking these are not beneficial? What should I do? They appear to be doing a lot of damage to new growth, so I am going to use a soap mixture to deal with them.

A: These red bugs (Lopidea major), also known as the sophora plant bug or mountain laurel bug, are relatively harmless although not beneficial.  They will suck some sap and do minor aesthetic damage to the new growth for a short time in the spring. They will not do enough damage to justify spending time and money managing them. Insecticidal soap is a good solution as an irritant for small soft-bodied insects and may disrupt their feeding activity.  If your soap solution doesn't work as you hope and you are determined to manage them, you might try an organic pyrethroid product called Pyganic that is more effective against plant bugs of this order.

Peter L. Warren is the urban horticulture agent for the Pima County Cooperative Extension and the University of Arizona. Questions may be emailed to tucsongardensage@gmail.com


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