The Pennsylvania Leather-wing Chauliognathus pennsylvanicus (that's a mouthful) is from the Soldier Beetle family.
This beetle is 3/8 inch long and brownish yellow with broad black lengthwise mark on the rear of each elytron. It's head, antennae, legs and underside are all black. It looks very much like our common "lightening bug" but it doesn't light up at night.
It's common to our area and seen in meadows, fields and gardens. I've seen many this summer. I'm often surprised when I enlarge a photo of a flower on my computer and there's several PLWs frolicking about.
They're soldiers and adeptly named. Adults eat pollen, nectar and small insects. Larva devour grasshopper eggs, small caterpillars and beetles. They are considered hugely beneficial insects, especially for the control of Corn Earworm caterpillars and cucumber beetles.
Some of the many plants they take pollen from are goldenrod, milkweed, hydrangea Queen Anne's Lace, Ox-eye daisies and many others. They have been pretty thick on my speedwell and typically like more flat surfaced or small Fleurette's.
Do NOT destroy these beetles by spraying insecticide on your flowers. They will do the work of destroying nasty insects and it will not hurt you or other beneficial insects.
You will often see two in a rather intimate embrace while mating on top of your flowers. The eggs are deposited in soil among ground litter. The Soldier Beetle produces two generations each year. The larvae overwinter in the soil or garden trash - another reason to let your garden have some decaying leaves and mess throughout winter.
The PLWs family are found worldwide, with 5,000 species in 135 genera.
Although they are slow moving and fliers, they have chemical defenses. Unlike many other beetles (which have a pair of defensive glands) These soldiers have two paired on the prothorax and one on each of their eight abdominal segments. They are consistently rejected as food by birds, mice, other beetles, ants, mantids, assassin bugs, centipedes, solpugids and jumping spiders. The chemical they secrete is (Z) - dihydromatricaria acid.
I just know you will use this insect chemical information at your next wine tasting party - thank me now or thank me then.
Happy First Day of Summer!