Owlfly Eggs

Stinkbug eggs - REK

Tonya Smith sent me these pictures of owlfly eggs she found on her fennel.  Their barrel shape resembles stinkbug eggs which would have been my first guess but those are usually found in a cluster on the underside of leaves.  I sent the picture to INaturalist and owlfly eggs didn't come in the top 10 suggestions.  

Owlflies are in the family Ascalaphidae.  The insect order Neuroptera, or net-winged insects, which includes the lacewings, mantidflies, antlions, and their relatives.  The vast majority of these are predators, consuming aphids and other species we consider pests.

Owlfly- Wikipedia

Adults resemble dragonflies except they have long clubbed antennae.  They tend to be rapid flying crepuscular hunters, and frequently are seen around porches and decks where they feast on other insects attracted to the lights.  When landing on a branch they hold their abdomen up at an angle, resembling a twig.  You can see the "net-wing" pattern in this photograph.

First instar larvae before dispersing -  Marita Beneke-Wikipedia

Graham Montgomery

Their larvae are also predators of many plant eating insects.  If you think the picture above bugs you, imagine the effect on a mother aphid in the neighborhood.  Notice the distinct head and a pair of huge caliper-like mandibles that are usually held wide open.  MDC's Discover Nature has this description of their life cycle.

"Female owlflies lay eggs in a line on twigs or plant stems. In addition to rounded, fertile eggs, she also lays a batch of smaller, “trophic” eggs nearby. These won’t hatch. They serve as a first meal for her hungry hatchlings and may prevent them from eating each other. They’re sticky and whorl around the stem like a fence, so they might also keep away ants or other predators. The young larvae move to the ground, where they hunt, eat, grow, and molt. They pupate, in a silky cocoon, in leaf litter."