In the dense foliage of summer it can be difficult to get through the ground cover of floodplain forests here in southeast Michigan. While out along the River Raisin last week, I found a dry creek bed that offered some ease of passage. On the banks were a number of swamp milkweeds (Asclepias incarnata, Asclepiadaceae), and is often the case they harbored many insects. On this excursion I encountered these banded longhorn beetles (Coleoptera: Cerambycidae: Typocerus velutinus) getting amorous on this particular food plant.
I’ve observed many different insects on swamp milkweed, including green stink bugs, oleander aphids, swamp milkweed leaf beetles and their larvae, jagged ambush bugs, large milkweed bugs, and monarch butterflies. This was the first time I had seen banded longhorn beetles, however.
Adult banded longhorn beetles feed on nectar and pollen, so their presence on a milkweed was fitting. As with many longhorned beetles, however, the larvae feed on trees. The young of this particular species are fond of rotting oaks and hickories.