Moth Mystery

I posted the following to "MOTHRA" this morning, and it occurs to me I may be missing some expertise elsewhere. If you get this twice, please use the "cancel" and get on with your life.

 

Folks:

I have (to me) a moth mystery. I have been a casual collector of
Notodontidae - principally because they look muchly like Noctuids. I
looked at my Heterocampa guttivitta the other day, consisting of
some 40+ specimens collected mostly here in Savannah between 1993
and the present, and between the months of March and October. I
noticed they ALL had pectinate antennae almost to the apex, with a
few simple segments at the end.

I checked with my friend W. T. M. Forbes, Part 2, pages 203 and
following, and that matches for males, but he says H. guttivitta
females have simple antennae. I then flipped them over and looked at
the frenulum on each. A single spine. A drop of alky on the wings of
a few show a narrow accessory cell. I then disected one (to look at
the genetalia and the eighth sternite) and that matches the
illustration for H. guttivitta.

Although Forbes said the male and female are similar, I figured I'd
check it see if I had mis-IDed some females. Data for my bugs is on
my PC, making searches easy. A short C++ program produced a list of
all Notos caught on the same date as my H. guttivitta specimens. I
looked at these carefully, and the ID is OK (most are P. angulosa,
which sport a tell-tale scale tuft on the inner margin of the FW.)

It seems to me that in 40+ specimens I'd have at least a few
females. Anyone have an idea - other than we have only homo bugs in
Savannah?

Jim Taylor