Fascista Identifications

In Oklahoma there are 3 species of Fascista known to occur, bimaculella, cercerisella, and quinella. The Redbud Leaffolder Moth (F. cercerisella) is by far the most commonly observed among these three species. However, I have found that often when F. quinella is observed it is misidentified as F. cercerisella. I think this is due to the prevalence of F. cercerisella and the iNaturalist suggestions only showing that species. I have spent some time going through all observations in Oklahoma and Texas which have been identified as F. cercerisella and provided disagreeing identifications for those that do not fit. These are most often F. quinella or Aroga compositella, although in one case I did notice a JUMPING SPIDER had been identified as F. cercerisella! After noticing the small geographic range of F. quinella I decided to expand my range of review to Arkansas, Kansas, Missouri, Louisiana, Florida, Georgia, Alabama, Mississippi, Tennessee, and Kentucky. I found at least one new state record of this species in Arkansas, which had also been misidentified as F. cercerisella and quite a few Aroga compositella which had been misidentified as well.

Redbud Leaffolder Moth (Fascista cercerisella)

Features which help identify this species are the creamy white head, series of three white markings along the outer margin of the forewings, faint orange spots in the center of the forewings, and white markings along the inner margin in the postmedial. Note that most of these features are consistent with F. quinella, with the exception of the feature in bold.

This species is known to occur throughout much of the eastern United States.

Fascista quinella

For this species I will point out features which differ from the aforementioned species. Note the white marking in the antimedial section of the wing is thinner. Where F. cercerisella has faint orange dots, F. quinella has a larger white marking. The central white marking along the outer margin is much smaller than seen on F. cercerisella.

Unlike the first species, F. quinella has a smaller geographic distribution, being known to occur in Oklahoma, Texas, and Florida.

The question of larvae and host plants

The lifecyle of F. cercerisella is well understood and extensively documented. Eggs are laid on the leaves of Eastern Redbud (Cercis canadensis). After the larvae hatch they stitch together a leaf (as seen above), and proceed to feed and then pupate inside this folded leaf. This behavior leads to the specific epithet cercerisella and the common name Redbud Leaffolder. Larvae are black and white striped.

There are no known photographs of F. quinella larvae and no known host plants. That being said, there are a number of photographs of larvae inside the folded leaves of Redbuds where the larvae are all white. I considered that these might be F. quinella, although it is possible that these are an earlier instar of F. cercerisella, as this photo of both white and striped larvae intermingled would suggest.

All of the photographs of Fascista quinella adults are on sheets or other human structures; none on plants.

Geography

Further, if F. quinella uses Eastern Redbuds as host plants then it is curious that the species has not been documented throughout the entire range of this tree, which is widespread in the eastern United States.

Flight time

Based on observations on iNaturalist, Fascista quinella appears to have two broods per year, with a first brief flight time peaking in early April and the second and longer flight time peaking in mid July but lasting from late June through early September. This suggests that caterpillars could be found in May and June.

The flight times and number of broods of F. cercerisella is less clear. There are probably two broods for this species as well, with the second flight being most prominent in July, followed by the most observations of larvae in September.

Next steps

I could answer the question of the white larvae by rearing those to adulthood. I could also try to pair some adult Fascista quinella to see what the resulting larvae look like, although doing this ex situ would not reveal the host plant. I would have to hope that someone recognized the resulting larvae as something that had been found on a host plant before but not correlated to an adult.

Posted on June 26, 2023 08:33 PM by zdufran zdufran

Comments

Great work, Zach!

Posted by jcochran706 10 months ago

I benefitted from this as well -- well done! :)

Posted by sambiology 10 months ago

I'll have to try to raise any white ones that I find.... It might be interesting to try to capture any known adults and see if they will lay eggs.

Posted by k8thegr8 10 months ago

Update: I collected and raised some of the small white larvae found in Redbud leaffolds and they turned out to be early instars of the Redbud Leaffolder (Fascista cercerisella). Later instars are the black and white striped.

Posted by zdufran 8 months ago

Mysterious!

Posted by k8thegr8 8 months ago

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