Crawlies with Cri: Broad antennae plant bug

Broad antennae plant bug (Heterotoma planicornis)

This week’s crawly is a beautiful, beneficial non-native bug from across the pond. Meet the broad antennae plant bug (Heterotoma planicornis).
Native to Europe, the broad antennae showed up in New York in 1915. They are now established in the Northeastern United States and on the West Coast, but not in between. They were introduced to New Zealand via Scotch broom plants, so that may be how they ended up in our area.
Thick antennas are members of the plant bug family (Miridae). If ever there were a family to get lost in, that’s the one. There are approximately 2,000 species of plant bugs in North America and about 10,000 worldwide.
As you might guess from their name, most plant bugs do live on and feed on plants. There are some predatory species like the thick antennas which feed on other critters that feed on plants.
Whatever their diet, plant bugs are common. Spend some time perusing the leaves in your garden and you’ll probably find a pretty plant bug or two.
Some plant bugs rock camouflage coloration, while others go for a brighter, bolder look. Most of them are quite small, ranging from under one-quarter of an inch to just over one-quarter of an inch.
However, none of the broad antennas’ North American cousins sport the funky, flattened antennae that give the broads their name (another common name is the thick antennae bug).
Though broad antennas are common and well-known in their native range, it’s still not known what advantage their stand-out-in-a-crowd antennae provide. Other than looking super cool, of course.
Broad antennas are one of the smaller plant bugs, falling between one-eighth and one-quarter of an inch. Despite their petite size, they are effective pest controllers. Both nymphs and adults dine on aphids, small plant hoppers and mites. They will drink nectar and the juice of unripe fruits if there is a lack of prey.
Plants and shrubs lower to the ground are the preferred patch for broad antennas. They do have fully formed wings as adults and can fly, but the tops of the trees aren’t appealing to them.
Broad antennas have one generation per year. In late summer or early fall females will lay a cluster of eggs under leaves of a plant likely to host aphids or mites and the eggs overwinter, hatching out in May or June. The nymphs are even smaller than the adults, but still sport the telltale broad antennae.
While it’s too late this season, you can look for broad antennas next spring and summer. They’ve been found in a few places in our area. Most adults won’t be as sparkly as our newly morphed-to-adult pictured bug. The metallic golden hairs rub off with age and adults appear black or dark red later in the season. However, those unique antennae always give you an easy visual for identification regardless of age or coloration.
Good luck!