This Alert focuses on the non-native Bristly Roseslug Sawfly. Although this sawfly and the European Roseslug have “slug” in their common names, they don’t share the slug-like body plan of other “slug sawflies,” and the larvae don’t cover themselves in shiny, slug-like slime.

Cressleaf Groundsel, commonly referred to as Butterweed, may look beautiful. But it is a weed and can be toxic to livestock if it is present in hay.

I recently came across odd leafmining activity on wild grape (Vitis spp.) growing in a local park in southwest Ohio. The leafmines were serpentine, named for their snake-like appearance, and they were filled with a dark line of excrement (frass). The leafmines ended in elongated expansions where the leafminer was no doubt pupating.

While on a walkabout in Winton Woods (Great Parks, Hamilton County) earlier this week, I came across a Black Maple (Acer nigrum) with new shoots and leaves that were wilted and blackened. The black maple was at the edge of a forest and had not been planted.

The malpractice of piling mulch high on tree stems to approximate the look of a volcano is well underway in Ohio. This horticultural horror, commonly known as a “mulch volcano” or “volcano mulch,” produces a range of detrimental effects, including reshaping tree root systems and interfering with water infiltration and retention.

Turf Team Times for May 15, 2026: Dr. Ed Nangle and Dr. David Garner discuss the weather shift and spring turf considerations. Dr. Gardner discusses weed control including crabgrass, rough bluegrass and creeping bentgrass, and broadleaf helleborine.

Leafminers are so named because they tunnel between the upper and lower epidermis to feed on the leaf mesophyll. Leafmining is a lifestyle with no connection to taxonomy. This Alert focuses on two leafminers belonging to the insect order Diptera (flies).

Dusky Birch Sawfly and Spiny Oak Sawfly larvae are appearing on their namesake hosts in southwest Ohio. They seldom cause significant injury to the overall health of their host trees; however, both can produce noticeable damage, drawing the attention of horticulture professionals and home gardeners.

Bagworms are the larvae (caterpillars) of a native moth. The caterpillars develop within silk bags festooned with pieces of their host plants. As the caterpillars mature, they begin weaving more host plant debris into the silk, which provides structural stability as well as highly effective camouflage.

On a recent visit to the doctor, I noticed trees in the parking lot at various stages of decline and death. It is a nice thought to plant trees in parking lot islands, but it usually ends poorly, especially for the tree!