"What a thousand acres of Silphiums looked like when they tickled the bellies of the buffalo is a question never again to be answered, and perhaps not even asked." -Aldo Leopold
Cloudless Sulphur Phoebis sennae (Linnaeus, 1758), fam. Pieridae, P-no. 77a0435 Host plants: Hosts on members of the legume family (Fabaceae), principally senna and partridge pea (Chamaecrista fasciculata). Date found(s): 4 August, 2026 Location(s) found: Ste. Genevieve County, MO Notes: By looking closely at the caterpillar pictured here, you may notice that its dorsum is covered in short setae that each contain a near-microscopic drop of fluid. In a study conducted on related Pieriis caterpillars, this fluid was found to be a sticky oil substance that had a deterrent effect on predation by generalist predators like ants (Shiojiri and Takabayashi, 2005).
Long-winged Dagger Acronicta longa (Guenée, 1852), fam. Noctuidae, P-no. 931485 Host plants: Reported feeding on woody species within nine plant families. In Missouri, I have found these on oak (Quercus spp.) and ash (Fraxinus spp.). Date found(s): 22 August, 2026 Location(s) found: Meramec State Park, Franklin County, MO Notes: Despite a species being considered a generalist across their range, individual lineages can be wildly picky eaters. In a rearing log documented on BugGuide, a citizen scientist hatched a clutch of A. longa eggs. Despite being surrounded by prime, classic host plants like oak (Quercus nigra) and cherry (Prunus sp.), the newly hatched caterpillars stubbornly refused to eat and began to starve. In a desperate last-ditch effort, the researcher offered them blueberry leaves (Vaccinium sp.). The caterpillars immediately devoured them, proving that while the species is a generalist, individual populations may dynamically “lock into” specific regional hosts.
Green Leuconycta Leuconycta diphteroides (Guenée, 1852), fam. Noctuidae, P-no. 932026 Host plant (s): Hosts on a variety of Asteraceae family members including fleabane (Erigeron spp) and goldenrod (Solidago spp). Date found(s): 28 June, 2026 Location(s) found: Pinewoods Lake Recreation Area, Carter County, MO Notes: Due to its host plant preferences, look for this moth in meadows, fields and prairies. If you plant native composite wildflowers, you may even have luck in finding them in your own backyard. The adult moth is a stunner and is often a popular subject when arriving at blacklights. It has received a common nickname in mothing circles—the “mint chocolate chip moth.”
Azalea Sphinx Darapsa choerilus (Cramer, 1779) P-no. 890208 Host plant: Roseshell azalea (Rhododendron prinophyllum) Date found(s): 4 August, 2026 Location(s) found: Hawn State Park, Ste. Genevieve County, MO Notes: Azalea sphinx moth caterpillars can be found during the daytime clinging to the midvein on leaves of their azalea hosts. In their disturbance pose, as seen in the fourth-instar caterpillar pictured here, I found them remarkably similar in appearance and size to the green developing fruits of the azalea.
Black-waved Flannel Moth Megalopyge crispata (Packard, 1864) P-no. 57a0038 Host plant: Not recorded Date found(s): 16 August, 2026 Location(s) found: Loggers Lake, Shannon County, MO Notes: In early to mid-August we found an abundance of these mid-instar black-waved flannel moth larva, literally dozens in this timespan. I got used to pretty much ignoring them, but recording them and the variety of hosta plants these generalists use. During a WGNSS trip, it was discovered that one of these was a bit more interesting than the others. In its downy white fluff, it held some sort of eggs. We pulled out the high magnification lenses to make sure we had a good chance at identifying these back home. Eggs of some parasitoid first came to mind, but these did not match anything obvious with those groups. After a Google session, we found these are most likely eggs of an assassin bug (fam. Reduviidae). It is unknown how or why the eggs found their way onto the caterpillar as assassin bugs typically oviposit on the surfaces of plants. Either the assassin bug chose a weird location to oviposit or perhaps the caterpillar collected these when moving about.
Mid-instar Megalopyge crispata larvae with Reduviidae eggs
Elm Sphinx (Four-horned Sphinx) Ceratomia amyntor (Geyer, 1835) P-no. 890102 Host plant: Found on American elm (Ulmus americana) Date found(s): July–August, 2026 Location(s) found: Carter County, MO, Ste. Genevieve County, MO; St. Louis County, MO Notes: An excellent example of camouflage. The four thoracic horns aptly mimic the teeth on the margins of the leaves on which they feed. These larva spend most of their time hiding upside-down on the undersides of elm leaves. The pale, oblique lines leading from the stomata to the mid-dorsal line let them blend in with elm leaves that feature prominent pinnate venation on their undersides (see photo).
Blinded Sphinx Paonias excaecata (J.E.Smith, 1797) P-no. 890144 Host plant: Found on black cherry (Prunus serotina) Date found: 5 August, 2026 Location found: Ste. Genevieve County, MO Notes: Note the red blotches that are surrounded by yellow, nicely mimicking later season leaves. This undoubtedly provides nice camouflage and may explain why certain color morphs are found on certain hosts.
Paonias excaecata larvae found on black cherry (Prunus serotina)
Tobacco Hornworm (Carolina Sphinx) Manduca sexta (Linnaeus, 1763) P-no. 890090 Host plant: Found on tomato (Solanum lycopersicum) Date found: July–August, 2026 Location found: St. Louis County, MO Notes: It took me long enough to collect some photos of this common species. This species is so common that most non-naturalists have seen them as they terrify their tomato plants they tend in backyard gardens. I had the pleasure of seeing a few of these this year, thanks to my pop, Bart, who invited me to photograph a couple he found on his tomato plants. He also gave me a few plants to grow in my backyard this year (mostly for the caterpillars). We found a couple, one of which I reared in a flight cage and has now went to ground to pupate. With luck, I’ll be able to see the adult moth next spring.
Witch Hazel Dagger Moth Acronicta hamamelis (Guenée, 1852) P-no. 931434.5 Host plant: Found on Ozark witch hazel (Hamamelis vernalis) Date found: 15–16 August, 2026 Location found: Logger’s Lake Recreation Area, Shannon County, MO Notes: The WGNSS Entomology and Nature Photography groups had a great joint overnight trip to Logger’s Lake this past weekend. Obviously, among the several entomofauna groups we focused on, caterpillars were high on our list. The species pictured here was one of our most exciting finds. During my studies of field guides and online sources to determine new caterpillar species to look for, the witch hazel dagger moth caught my attention. Southeastern Missouri has plenty of its obligate host plant afterall. However, after looking on iNaturalist a couple of years ago, I discovered there were no documentations of this species in our state. Checking with the Heitzman catalogue, I found that there was only one recorded observation in Missouri—from 1889! I still kept this species in mind; there were a few documentations in Arkansas and eastern Kentucky and Tennessee, and as I mentioned, the host is abundant in Missouri.
During our caterpillar hikes this past weekend, we were delighted to find seven Acronicta hamamelis larvae at various stages. I collected a couple to take home and hopefully rear to adults. The more advanced individual spent the next day feeding on my ozark witch hazel and then changed to its warm pre-pupal coloration. It has since made a cocoon and I hope to see an adult eventually.
Luna Moth Actias luna (Linnaeus, 1758) P-no. 890072 Host plant: Found on pawpaw (Asimina triloba) Date found: 28 June, 2026 Location found: Pinewoods Lake Recreation Area, Carter County, MO Notes: While the adult luna moth does not feed at all, the larvae are highly polyphagous. The recorded hosts are plants in 18 families, utilizing mostly woody species.
A Thousand Acres of Silphiums 