2026 Caterpillar Season – Common Buckeye

2026 Caterpillar Season, insects, Lepidoptera, macro, wildlife, wildlife photography

Common Buckeye
Junonia coenia (Hubner, 1822), fam. Nymphalidae, P-no. 77a0831
Host plants: Hosts include members of the figwort (Scrophulariaceae), plantain (Plantaginaceae), and acanthus (Acanthaceae) families.
Date found(s): August 22, 2026
Location(s) found: Meramec State Park, Franklin County, MO
Notes: The common buckeye’s preferred hosts contain quantities of the bitter and toxic compounds called iridoid glycosides. The caterpillars sequester these compounds and gain considerable protection from them against predators like birds and wasps. However, this protection can come with a considerable tradeoff. High concentrations of iridoid glycosides have been shown to reduce the caterpillar’s immune system, making it incredibly vulnerable to parasitic wasps, flies, and deadly pathogens. To avoid this, female buckeye adults carefully taste potential host plants, striving for just the right amount of iridoid glycosides, prior to choosing the specific plant to oviposit upon.

For the common buckeye, the benefits of this chemical sequestration do not continue to the pupal and adult life stages. Larvae actively metabolize the iridoid glycosides, and these compounds have been shown to drop considerably in late fifth-instar caterpillars and eventually become undetectable in adults. Adults then adopt a different strategy of using warning coloration and patterning of the large “buckeyes” to deter would-be predators.

2026 Caterpillar Season – Silver-spotted Skipper

2026 Caterpillar Season, Caterpillars of Tyson Research Center, Lepidoptera, macro, wildlife, wildlife photography

Silver-spotted Skipper
Epargyreus clarus (Crammer, 1755), fam. Hesperiidae, P-no. 70044
Host plants: Hosts on members of the Fabaceae, including Amporpha, Desmodium, Robinia, and Gleditsia.
Date found(s): September 6, 2026
Location(s) found: Tyson Research Center, St. Louis County, MO
Notes: Here is a lepidopteran even most novice naturalists are familiar with. This is a common and large skipper that is easily identified by the white-silver spots located on the ventral side of the hind wings. This species is often found in backyard gardens and even in urban areas. Caterpillars of this species are best found by looking for leaf tents they build among the foliage of false indigo, wisteria, or other Fabaceae species.

2026 Caterpillar Season – Goatweed Leafwing

2026 Caterpillar Season, insects, Lepidoptera, macro, WGNSS Field Trips, wildlife, wildlife photography

I shared photos of caterpillars of the goatweed leafwing last year. Last month, the WGNSS Nature Photography Group went to Don Robinson State Park in Jefferson County, MO for our annual late season caterpillar hunt and found quite a few of these guys on thier croton host plants. I was pleased to get a nice photo of a couple of active late instar larvae pictured here.

And Now for Something COMPLETELY different

Hymenoptera, insects, macro, wildlife, wildlife photography

I figure any regular viewers of this blog may be getting a little tired of all the caterpillar posts. So, to mix things up a great deal, today’s post is an image of a larval elm sawfly (Cimbex americanus) that I photographed in late May at Tyson Research Center in St. Louis County, MO. Despite looking very much like a caterpillar, I assure you it is not. The sawflies, also known as horntails and wood wasps, are an old lineage (first appearing in fossil records roughly 250 million years ago) within the order Hymenoptera (bees and wasps). The larvae can be distinguished from caterpillars by possessing extra sets of prolegs (six pairs or more). Caterpillars have five or fewer pairs of prolegs. The prolegs of sawflies also lack crochets—the hooklike structures found on the ends of caterpillar prolegs.

The elm sawfly is the largest sawfly in North America. The animal pictured here was very close to two inches long. Accordingly, the elm sawfly adults are large as well, with black, white and red markings making it look very much like an intimidating wasp. No worries there, however, as sawflies do not possess a stinger.

A giant elm sawfly larva. Note the crochetless prolegs. Four pairs of prolegs are visible in this image, but three other pairs can be found in the posterior portion of its body.

2026 Caterpillar Season – Lace-capped Caterpillar

2026 Caterpillar Season, Caterpillars of Tyson Research Center, insects, Lepidoptera, macro, wildlife, wildlife photography

Lace-capped Caterpillar (White-streaked Prominent)
Ianassa lignicolor (Walker, 1855), fam. Notodontidae, P-no. 930106.7
Host plants: Primarily oaks (Quercus spp.).
Date found(s): August 29, 2026
Location(s) found: Tyson Research Center, St. Louis County, MO
Notes: For decades, this moth was known as Oligocentria lignicolor. However, recent genomic research revealed that it was more closely related to the genus Ianassa. This taxonomic revision is a great example of how modern DNA sequencing is proving that species which look similar (like Oligocentria) are not always the closest relatives.

2026 Caterpillar Season – Angulose Prominent

2026 Caterpillar Season, insects, Lepidoptera, macro, wildlife, wildlife photography

Angulose Prominent
Peridea angulosa (J.E.Smith, 1797), fam. Notodontidae, P-no. 930049
Host plants: Primarily oaks but hickory has been reported.
Date found(s): August 22; September 6, 2026
Location(s) found: Little Creve Coeur Ecological Area, St. Louis County, MO
Notes: Two other members of this genus, the oval-based prominent (Peridea basitriens) and chocolate prominent (P. ferruginea), are found in Missouri and look somewhat similar to the angulose prominent. However, the angulose prominent is the only one of the three to host on oaks. Oval-based prominent hosts on maple and the chocolate prominent hosts on birch.

2026 Caterpillar Season – Spotted Apatelodes

2026 Caterpillar Season, Caterpillars of Tyson Research Center, insects, Lepidoptera, macro, wildlife, wildlife photography

Spotted Apatelodes
Apatelodes torrefacta (J.E. Smith, 1797), fam. Apatelodidae, P-no. 890001
Host plants: Highly polyphagous. Documented feeding primarily on woody species in 18 plant families. I have found these most often on redbud (Cercis canadensis), black cherry (Prunus serotina), and sassafras (Sassafras albidum).
Date found(s): August 22; September 6, 2026
Location(s) found: Meramec State Park, Franklin County, MO; Tyson Research Center, St. Louis County, MO
Notes: Large, covered in long setae with long, black middorsal “lashes.” Shorter urticating setae are found underneath that can deliver stings. Come in two “flavors:” lemon chiffon, or frosty white. Also look for the diagnostic red abdominal prolegs. This species shows up regularly on late summer or early autumn caterpillar hunts. This is likely due to their large size, bright color, and the habit of resting conspicuously on the leaves on which they feed.

2026 Caterpillar Season – Brown-hooded Owlet

2026 Caterpillar Season, insects, Lepidoptera, macro, WGNSS Field Trips, wildlife, wildlife photography

Brown-hooded Owlet
Cucullia convexipennis (Grote & Robinson, 1868), fam. Noctuidae, P-no. 931513
Host plants: Specialist hosting on goldenrod (Solidago spp.) and other Asteraceae family members.
Date found(s): September 12, 2026
Location(s) found: Don Robinson State Park, Jefferson County, MO
Notes: Due to the apparent lack of high concentrations of toxins in their hostplants that are sequestered by many lepidopterans for defense, the aposematic coloration exhibited by the brown-hooded owlet is potentially a case of Batesian mimicry. Although the specific model species has not been identified, caterpillars and other insects use yellow, black, red, and white color combinations to advertise their toxicity.

2026 Caterpillar Season – Yellow-necked Caterpillar Moth

2026 Caterpillar Season, insects, Lepidoptera, macro, wildlife, wildlife photography

Yellow-necked Caterpillar Moth
Datana ministra (Drury, 1773), fam. Notodontidae, P-no. 930033
Host plants: The recorded hosts are a wide variety of woody species in 15 plant families.
Date found(s): August 22, 2026
Location(s) found: Meramec State Park, Franklin County, MO
Notes: The yellow-necked caterpillar, like most Datana, go through several color phases as they develop. Early instars are reddish -brown to green. Mid-instars become striped but may be considerably different colors than the final instar. Although Datana caterpillars may be easy to identify at most stages, getting them to species is usually best accomplished with final instars.

2026 Caterpillar Season – Afflicted Dagger

2026 Caterpillar Season, insects, Lepidoptera, macro, wildlife, wildlife photography

Afflicted Dagger
Acronicta afflicta (Grote, 1864), fam. Noctuidae, P-no. 931419.77
Host plants: Feeds principally on oaks (Quercus spp.). Also reported on gum trees (Nyssa spp.).
Date found(s): September 17, 2026
Location(s) found: St. Louis County, MO
Notes: A visually similar and closely related species, Acronicta brumosa (charred dagger), has a single record (1913) from Missouri in the Heitzman database. The charred dagger is a more southerly species but does have more modern records from Arkansas, Oklahoma and southern Illinois. Larvae of the charred dagger can be distinguished from A. afflicta by the presence of two pairs of paddle-shaped dorsal setae per segment.