Throybes confusion

[Ron Gatrelle]

My first encounters with Thorybes confusis (Confused) and bathyllus
(Southern) was in 1968 while living in Pensacola, Fla. By the time I moved
to Charleston in 1970 I was confused by the facies of numerous specimens I
had encountered in FL and SC. So I decided to take a more scientific look
at these two. The genitalia of these two are large and easily dissected and
very different.

By examining the genitalia of various samples I found that the spring brood
of bathyllus looks identical to, or often darker than, the summer brood of
confusis. I also found that true spring confusis are almost unspotted on
the dorsal wings of males and lightly marked in females. In both species
their respective spring broods are much less spotted than their respective
summer broods. Since then I have examined probably 3 to 4 hundred specimens
in institutional and private collections. Invariably the spring brood of
bathyllus is misidentified as confusis in these collections. I have also
seen many summer confusis misidentified as bathyllus. The same holds true
for sight records.

This lack of accurate identification is equal with collectors and watchers
because both have based their determinations on the figures in the
literature, which are often inaccurate, incomplete, or only of the summber
broods. Virtually all skipper experts agree with Allen in the Butterflies
of West Virginia that many specimens can only be told apart by dissection.
(His determinations are correct - except I think his ventral confusis is a
female by the shape of its HW.)

So do some specimens have to be killed and dissected to know for sure which
taxon they are? Not after you read this post. Here is how to tell them
apart.

The summer brood of Southern Cloudys (bathyllus) are very boldly marked.
The hindwings have a distinct almost white margin, and the four tiny
hyaline spots at the apex of the forewing are ALWAYS in a straight line and
look almost like one triangular spot - the small picture at the right in
the Audubon Guide

The summer brood of Confused Cloudys (confusis) have dark or only slightly
lighter HW margins, their FW spots are not as pronounced but are usually
very evident, the line of tiny spots at the apex ALWAYS has the last spot
strongly disjunct toward the apex. - Yes, that would make the big
"bathyllus" in the Audubon Guide actually a summer confusis female! (The
Eastern specimen above it is also a likely misidentification. I have spring
bathyllus females which look just like that.)

The spring brood of bathyllus looks like that of summer confusis ( or even
less spotted), the only sure way to tell them 99% is the shape of the line
of spots at the apex which are ALWAYS in a straight line.

The spring brood of confusis is as described above. The only 99% positive
sight character is the alignment of those apical spots which ALWAYS have
the last one (into the wing) clearly offset toward  the outside (margin) of
the wing.

Anyone who argues with this is wrong. I dissected a lot of specimens 20
years ago and the only 99% correlation between the genitalia and the
markings in all broods for both species was the alignment of the apical
line of spots. Don't let the field guides or your eyes fool you. A lot of
very experienced people have mistaken (and are mistaking) lightly marked
spring Southerns (bathyllus) for Confused (confusis) and more heavily
marked summer Confused (confusis) for Southerns (bathyllus).

Should I address juvenalis and horatius next? There are some surprises here
too if you check the genitalia.

Good IDing
Ron


 
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