aureleah_aurita's Journal

(Skip to squiggly line to ignore my ramblings and get to the ID info! All info from paper cited at end)

National Moth Week takes place the last week of July every year. I joined iNaturalist in April 2022 for the City Nature Challenge and soon after participated in the NC Moth Count in July. After that, my eyes were always on the lookout for neat moths to photograph. Soon after moth week wrapped up, on August 4, 2022, I photographed a striking, striped moth that was ID'd as being in the genus Doryodes, thanks to iNat's computer vision suggestion.

Then, a week later, I saw a second one, and once again iNat's computer vision suggested Doryodes to me.

For the next year, those observations would sit in "Needs ID" limbo, largely forgotten by me, until this year's moth week.

On the first day of moth week, July 22, I found another one of those neat striped moths! This time, however, iNaturalist did not have a suggestion for me beyond "Owlet Moths and Allies". I recognized it though and remembered them being ID'd the year prior, so I went back and relearned the genus name to be able to ID my moth later that day.

Two days later, my fourth Doryodes moth appears, and at this point I'm starting to get curious what species it is, so I throw a haphazard Dull Doryodes Moth Doryodes spadaria ID on it, maybe in slight hopes it will get the attention of another IDer. I think "Dull Doryodes" just sounded like it could be familiar and it looked very similar to what I was seeing.

Towards the end of moth week, I start going through my observations to try and refine some IDs where I can. I decide to see what different Doryodes species are documented in my area, so I go to the Moths of North Carolina website and create a checklist for macromoths in the coastal plain and find three contenders, including one species that's only found in eastern NC, which excited me and led to me IDing all of my observations as that species, but I know it's hard to actually tell the difference between these without dissection so I'm going handle this the way I always do when I have something difficult to ID: compile some notes in an iNat journal post in hopes some combination of traits will help me narrow down my options!

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Doryodes bistrialis (8765) Double-lined Doryodes
• male forewing: 13.5–15.5 mm, female forewing: 14.5–16.0 mm
• narrowest brown stripe of the three
• inland species of pine savannah associated with wiregrass; North Carolina to Florida and Mississippi
• Doryodes bistrialis, unlike all other species in the genus, occurs mainly inland away from coastal salt marshes. It occurs in pine savannas where wiregrass (Aristida stricta), the presumed food plant, is abundant... The species is on the wing from April through October in North Carolina... In North Carolina the savannas are usually a half mile or more inland from coastal marshes and extend westward into the Sandhills adjacent to the piedmont. It is possible that the salt marsh species and the wiregrass species could occur in the same or very close areas where coastal marshes penetrate inland but we did not find such areas.
• The first iNat record of a Doryodes in NC is currently considered a research-grade bistralis. This is also the only research grade Doryodes in the state. All of my moths are seen near a barrier island marsh, and while there is abundant Aristida grass on the north side of the island, there isn't as much on the south side where my observations are taking place. I would rule this species out based on habitat, but the research-grade bistralis was observed on Cape Hatteras, where the available habitat is more similar to mine, so I'll keep it in consideration.

Doryodes fusselli (8767.1) Fussell's Doryodes
• male forewing: 12-17mm (16-17 in spring, 14-15 in summer, some 12-13 in late summer)
• female forewing: 16mm
• Larger than bistralis, smaller (especially females) than spadaria
• The medial chocolate stripe on the forewing is broader than in D. bistrialis, but narrower than that of D. spadaria
• Dare County south to Brunswick and New Hanover counties in NC
• The hindwing is pearly white, without the buff coloring of D. spadaria.
• salt marsh species known only from coastal North Carolina
• species appears to be on the wing continuously

Doryodes spadaria (8767) Dull Doryodes Moth
• Doryodes spadaria is the most widespread and common species in the genus, and except for Doryodes fusselli in coastal North Carolina
• male forewing: 13-20 mm (most commonly 16-18)
• female forewing: 18–21 mm (most commonly 19 mm)
• In late summer some males of D. spadaria can have white hindwings, but size ranges for the two species (D. spadaria and D. fusselli) do not overlap in this generation.
• Atlantic Coast from Canada to southern Florida

Lafontaine JD, Sullivan JB. A revision of the genus Doryodes Guenée, 1857, with descriptions of six new species (Lepidoptera, Erebidae, Catocalinae, Euclidiini). Zookeys. 2015 Oct 15;(527):3-30. doi: 10.3897/zookeys.527.6087. PMID: 26692785; PMCID: PMC4668885.

Here we go! This time with tiger moths

According to Moths of North Carolina website, there are three Spilosoma species to be found in the NC Coastal plain.

Spilosoma congrua
Spilosoma dubia
Spilosoma virginica
and BugGuide mentioned that Hyphantria cunea can be confused with the others, and moths of NC had it on the coastal plain checklist as well, so we'll look at that as well. All of the following information is taken directly from BugGuide unless otherwise mentioned.

Virginian Tiger Moth Spilosoma virginica

• wingspan 32-52 mm
• "S. virginica has yellow markings on the abdomen"- Paul Dennehy
• tibiae and tarsi will be strongly white with complete or partial black banding dorsally along the tarsi.
• Yellow egg masses

Agreeable Tiger Moth Spilosoma congrua

• wingspan 27-47 mm
• "S. congrua's abdomen is pure white" - Paul Dennehy
• tibiae and tarsi will be solid white laterally, bordered by solid black medially along the interior of the tibiae/tarsi with a clear demarcation and no banding on tarsi.
• White egg masses

Dubious Tiger Moth Spilosoma dubia

• wingspan 32-38 mm
• Yellow areas on abdomen. Black dots down dorsal abdomen- dots are larger than H. cunea's (personal observation, not from BugGuide).

Fall webworm moth Hyphantria cunea

• wingspan 25-42 mm
• has small row of dots down dorsal abdomen
• tibiae and tarsi vary – in immaculate specimens the tibiae/tarsi is often completely white/pale, while in heavily marked specimens, the tibiae/tarsi are completely black.
• In other lighter marked specimens, tarsi may appear banded and most similar to S. virginica, but will only appear so laterally with solid black/dark medially.
• When dealing with this variation, it’s typically described as H. cunea having dark tibiae/tarsi, the tarsi banded with white, verses S. virginica having mostly white tibiae/tarsi, the tarsi banded with black.
• very pale green egg masses