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Polybiomyia macquarti
Photo#1513647
Copyright © 2018
Jeff Gruber
Syrphid -
Polybiomyia macquarti
-
Resaca De La Palma State Park, Cameron County, Texas, USA
August 9, 2017
Polybiomyia macquarti
?
Contributed by
Jeff Gruber
on 28 April, 2018 - 7:37am
Last updated 8 June, 2018 - 4:53pm
Great find & photo, Jeff!
Thanks for posting this...good to have an exemplar of a female (from "eyes separated"), to complement the single previous BugGuide post of a male.
Williston, in his
original description
of a single female (under the preoccupied name
Ceria scutellata
), had seemed to imply that his type specimen had a
single
, large, prescutellar spot of trapezoidal shape. Shannon(1925) indicated that he had: "Two males; one female, the type, at hand. The males have the prescutellar spot divided." It seems both your female here (from dichoptic eyes) and that seen
in this iNat post
also have the trapezoidal presutellar spot "divided" (at least partially). So, contrary to the sugesstion in Shannon(1925), it appears the character of prescutellar spot "entire vs. divided" is not a consistent sexual dimorphism for the species.
BTW, your find is from very near Brownsville and the Mexican border, at the southern tip of TX...where Shannon(1925) gave a record for
P. macquarti
from June 5, 1904. The previous BugGuide post is from Victoria, TX...about 190 miles to the north.
…
Aaron Schusteff
, 8 June, 2018 - 4:53pm
Thank
Aaron,
Thanks much for the wonderful and thorough commentary. Great info to have in the guide.
…
Jeff Gruber
, 20 June, 2018 - 5:51am
Moved
Moved from
Cerioidini
.
…
Martin Hauser
, 28 April, 2018 - 7:30pm