Look Out for Leafminers

We do not often see leafminers on magnolia, but the Plant and Insect Diagnostic Clinic received a sample that I suspect is damage is from the magnolia serpentine leafminer moth (Phyllocnistis magnoliella).  

The caterpillar stage of this moth feeds close to the upper epidermis of the leaf and causes long, sort-of-silvery mines all over the leaf. They are not considered a pest of magnolia as usually it is only a few leaves that are affected. 

Very little seems to be known about this moth's life-cycle. As with all leafminers control is not practical because the insect is protected within the leaf.  If you notice them on your magnolia just enjoy the pretty winding lines on the leaves. 

Signs of a leafminer. Photo courtesy of Matthew Bailey.


Links to this article are strongly encouraged, and this article may be republished without further permission if published as written and if credit is given to the author, Horticulture and Home Pest News, and Iowa State University Extension and Outreach. If this article is to be used in any other manner, permission from the author is required. This article was originally published on June 4, 2021. The information contained within may not be the most current and accurate depending on when it is accessed.