"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
Yellow-collared Slug Moth
Apoda y-inversum fam. Limacodidae (Hodges#4667)
Host plant: Found on black walnut (Juglans nigra)
Date found: 31 August, 2025
Location found: Tyson Research Center, St. Louis County, MO
Notes: These photos show a mid-instar caterpillar with stinging setae that are absent in final instars.
Red-crossed Button Slug
Tortricidia pallida fam. Limacodidae (Hodges#4653)
Host plant(s): Found on white oak (Quercus alba)
Date(s) and location(s): 31 August, 2025 – Tyson Research Center, St. Louis County, MO
Notes: Click here to see adult.
Skiff Moth
Prolimacodes badia fam. Limacodidae (Hodges#4671)
Host plant(s): Found on chinquapin oak (Quercus muehlenbergii)
Date(s) and location(s): 31 August, 2025 – Tyson Research Center, St. Louis County, MO
Notes: This poor cat is host to a tachinid fly larvae. A closeup image is included showing the egg as well as the larvae that has pierced the skin of the caterpillar in order to breath.
Crowned Slug Moth
Isa textula fam. Limacodidae (Hodges#4681)
Host plant(s): Found on sassafras, northern red oak, redbud
Date(s) and location(s): 31 August, 19-September, 2025 – Tyson Research Center, St. Louis County, MO; 27 September, 2025 – Caney Mountain Conservation Area, Ozark County, MO
Notes: By far the most numerous Limacodid I found in 2025.
Nason’s Slug Moth
Natada nasoni fam. Limacodidae (Hodges#4679)
Host plant(s): northern red oak (Quercus rubra), hackberry (Celtis occidentalis), white oak (Quercus alba)
Date(s) and location(s): 23, 31 Aug, 2025 – Tyson Research Center, St. Louis County, MO
Notes: West of the Mississippi River, this species is rarely found north of the Missouri River.
Spun Glass Slug Moth
Isochaetes beutenmuelleri fam. Limacodidae (Hodges#4675)
Host plant(s): northern red oak (Quercus rubra)
Date(s) and location(s): 23 Aug, 2025 – Tyson Research Center, St. Louis County, MO
Notes: The feathery appendages of this slug moth caterpillar do not contain urticating spines and do not sting. These dense and soft setae may act as a deterrence to potential wasp and fly parasitoids in blocking easy access to the body of the caterpillar in placing or injecting eggs.
The following images were taken of a band of travelling slug moth caterpillars during our overnight WGNSS trip to Council Bluff Lake in mid-August of this year. Many thanks to Eva Weideman who collected these from her home hunting grounds in Franklin County, MO and brought them for us to observe and photograph.
Euclea delphinii (spiney oak slug moth)
Isochaetes beutenmuelleri (Beutenmueller’s slug moth/spun glass slug moth)
Parasa chloris (smaller parasa)
Parasa indetermina (stinging rose moth)
Saddleback
Acharia stimulea fam. Limacodidae (Hodges#4700)
Host plant: Sassafras (Sassafras albidum)
Date found: ~02, Aug, 2025
Location found: Trail of Tears State park, Cape Girardeau County, MO
Notes: Three caterpillars were found at this date and location. One was found on pawpaw (Asimina triloba) and two on sassafras (Sassafras albidum).
Red-crossed Button Slug
Tortricidia pallida fam. Limacodidae
Host plant: red oak member (Quercus sp.)
Dates found: 14, Sep, 2024
Locations Found: Kaintuck Hollow, Phelps County, MO
Notes: Although we supposedly have two other button slug species in Missouri, this is the only one I’ve been able to identify. Very common.
Crowned Slug Moth
Isa textula fam. Limacodidae
Host plant: Found on sassafras (Sassafras albidum)
Dates found: 5, Oct, 2024
Locations Found: Daniel Boone Conservation Area, Warren County, MO
Notes: I was getting a bit tired of simply shooting slug moth caterpillars from the typical overhead viewpoint that is often seen with these “flatter” species. In this image I used the Canon TS-E 90mm f/2.8L macro lens along with a 36mm extension tube. This allowed me to change the plane of focus in order to get the entire animal with acceptable depth of field despite the angle I shot it with and get the magnification and detail I wanted. It isn’t necessarily the most pleasing image compositionally, but I have used this approach with several slow moving slug moth caterpillars this season and I am liking this technique.
A Thousand Acres of Silphiums 
