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Howdy, BugFans,
We’ll ease into 2025 with a few short pieces about bugs for whom there is very little info available — and yet they are lovely. They spend their lives doing their jobs and are recycled in the end — living, all-in-all, admirable existences.
Arrowhead Weevils
These weevils are in the genus Listronotus in the Snout and Bark beetle family Curculionidae. The BugLady loves wetlands, and arrowhead plants (Sagittaria sp.) grow in wetlands, and Arrowhead weevils grow in/on arrowheads. There are about 80 species in the genus Listronotus (which means “spade-backed”), and they’re found in wetlands throughout the Americas.
According to Bugguide.net, “Photos can rarely be taken to species with any confidence” and their link to genus keys includes the caveat “use with caution,” but let’s call this one Listronotus appendiculatus (no common name). Listronotus appendiculatus is found on sedges and arrowheads in wet prairies in a patchwork of states over the eastern two-thirds of North America. They come in a variety of shades from grayish to rust, and they have fantastic faces.
One publication said “Biological information is limited, even for the most common species.” Adults eat the flowers and fruit of their host plants. Eggs are laid in the flower stalks where the larvae feed and grow, their presence often indicated by globs of latex that is exuded by the plant to cover the holes they make. Newly-minted (teneral) adults stay in their pupal cells until their shell hardens.
Wood-Boring Mason Wasp (Euodynerus foraminatus)
Mason wasps have graced these pages before. According to Heather Holm in her (fabulous) book about North American wasps, Mason wasps are solitary wasps, most of which nest in cavities above the ground. They excavate multiple cells, into each of which they insert an egg, hanging it from the cell’s ceiling on a thread, and then they stuff provisions in the form of small invertebrates into the cells and use mud or sand to separate and cap them.
[Quick Aside: Holm’s book excludes the Ichneumon wasps, Ichneumonidae — the BugLady wishes she’d do one about the Ichneumonidae, though there are so many of them that the BugLady might not be able to lift it.]
The wood-boring mason wasp constructs her egg cells in hollow twigs, old paper wasp nests, decaying stumps or trees, or man-made substances like cardboard, often near the edges of woodlands. She is solitary, but she doesn’t mind her sisters nesting nearby. She hunts for and paralyzes small caterpillars from several micro-moth groups for her offspring’s’ eventual needs – from three to fourteen of them per cell, depending on the size of the caterpillars and the size of the female wasp. Cells with more provisions, not surprisingly, produce larger adults. Males may patrol good nest-building areas and when a single male controls a territory containing multiple females, he may mate with all of them.
Common Oblique Syrphid Fly (Allograpta obliqua) aka the Oblique Streaktail
Isn’t this a spiffy little (quarter-inch) fly! Syrphid/Hover/Flower flies (family Syrphidae) are also frequent BOTW flyers. Their Super Power is that they can fly both forward and backward and can hover. The BugLady’s picture doesn’t really demonstrate the “oblique” part of its name at the end of its abdomen, but this photographer caught it.
COSFs are found across much of the US and in eastern Canada, and they’re both habitat and food generalists. Adults feed on pollen and nectar, but their larvae are carnivores, so Mom lays her eggs near a good food source, like a herd of aphids. The larvae also eat whiteflies, mites, mealybugs, and psyllids (jumping plant lice) (and, alas, some butterfly larvae), and this very small fly is a great biological control of some of the aphids that attack citrus and some other agricultural crops.
The BugLady has said that the people who named Tiger beetles and Underwing moths were sure having fun. Add the Syrphid flies to that, with groups like the meadow and conifer flies, smoothtails, whitebelts, bristlesides, gossamers, streaktails, smoothlegs, pitheads, sapeaters, wrinkleheads, logsitters, mucksuckers, pufftails, sicklelegs, thicklegs, leafwalkers, and more.
Bonus points if you know what plant the Syrphid fly is sitting on.
The BugLady