This Codatractus sp.
was photographed at the Mission RV Park Hedge on August 8th 2004:
There was some discussion on whether it could be identified to
species; Mike Overton suggested that C. alcaeus and C.
carlos are the two that are likely to be
confused, while hyster, bryaxis, melon and
sallyae are also somewhat similar to each other. I think
that all records of Codatractus from the LRGV have been
claimed to be alcaeus, but there is no confirmed specimen
(please correct me if I'm wrong.) I have no experience of this
genus outside this individual, but there are a series of eight
specimens (dorsal and ventral views) each of alcaeus and
carlos available at this
website that offer a possible means of separating these two
taxa.
On the two images below I have circled the areas that I feel may
be useful:- A: the size of the FW apical
spots seems consistently different between all eight alcaeus
and carlos, in that the former has four large spots that
connect with each other while the latter has three small spots
with a gap between the inner two and outermost one. B: each taxon has a row of four large submedian pale blocks
on the FW; on alcaeus the lowermost block has its basal
edge aligned below the third block, creating overlap; on carlos
the lowermost block has its basal edge beyond the outer limit
of the third block, thus having no overlap. C: the difference here is hard to put into words, but fairly
easy to see:- basically on alcaeus the twin dark marks
coalesce in the central portion then taper out in a fairly straight
line well away from the dark block on the extreme right of "C";
on carlos the twin marks never seen to coalesce, instead
the outer one either disappears, or continues as a ghost paralleling
the inner dark mark, which stays the same thickness throughout
and tends to have a more sudden downturn away from the dark block
at the extreme right, with a smaller or non-existant pale gap
between them. D: this is less clear, but on alcaeus the two dark
blocks at the lower-right of "D" tend to touch or overlap,
while on carlos these usually don't touch
- I realise that this is a small sample, but the differences in
A, B, and C seem quite clear and consistent - and the Mission
bug fits alcaeus on all counts.... I'd appreciate feedback
- thanks.
