Three members of the order Hemiptera (True Bugs) are stomping around Ohio right now. Boxelder Bugs (Boisea trivittatus) are appearing in home landscapes. Western Conifer Seed Bugs (Leptoglossus occidentalis) are appearing on developing conifer cones, and Magnolia Leaf-Footed Bugs (L. fulvicornis) are appearing on the seed pods of their namesake host.
Four Things in Common
1. What’s in a Name
The three bugs belong to the order Hemiptera (the True Bugs). The prefix “Hemi-“ means “half,” and the suffix “-ptera” means “wing.” The front half of the front wings of hemipterans is hardened, and the back half is membranous.
2. They Suck
The bugs use their piercing-sucking mouthparts housed in a proboscis to inject enzymes that dissolve plant tissue, then they suck up the slurry.
3. No Harm
The bugs feed on seeds or seed pods, so they cause no appreciable harm to the overall health of their plant hosts.
4. A Nuisance
The bugs have a bad habit of invading homes and other structures in the fall, so they can be serious nuisance pests.
An Overview
Both the magnolia leaf-footed bugs and the western conifer seed bugs are leaf-footed bugs (family Coreidae). Leaf-footed bugs get their name from the leaf-like expansions of their hind tibia. It’s a bit confusing because their "feet" which are called tarsi (tarsus singular) are the leg segments they walk on.
Although leaf-footed bugs are not closely related to stink bugs (Family Pentatomidae), many species share a similar chemical defense strategy with their odiferous distant cousins. Leaf-footed bugs sequester defense secretions in thoracic glands; most of the chemicals are straight-chain aldehydes and ketones. If threatened, they can emit a strong, unpleasant odor.
As their common name implies, the highest populations of western conifer seed bugs are in landscapes or woodlots with large numbers of conifers. At this time of the year, overwintered adults are being replaced by their progeny. Look closely for nymphs sipping sap from developing pine cones.
Landscapes with mature magnolias will attract magnolia leaf-footed bugs. Participants in the OSU/OGIA Southwest Ohio Diagnostic Walk-About this past Monday found magnolia leaf-footed bug adults feeding on newly developing magnolia seed pods. Nymphs will appear much later in the season.
Boxelder bugs belong to the family Rhopalidae, the scentless plant bugs. So they lack a chemical defense. They use their piercing-sucking mouthparts to feed on the seeds of their namesake host, boxelder (Acer negundo), as well as other Acer species and ash (Fraxinus spp.).
Consequently, large numbers of the bugs are commonly associated with seed-bearing boxelders or other maples growing in landscapes or woodlots. At this time of the year, a few lingering adults may be found among large numbers of nymphs. It’s not uncommon for large aggregations of boxelder bugs to appear in landscapes. While they may sip on some plant sap, the bugs cause no harm and they do not bite.
