In a collection of several species of Stratiomyidae from Ohio, and a
number of western species, I find something which may be of interest to
students of the family.
Specimens of _Allognosta fuscitarsis_, Say, show some degree of
variation in the extent of the pale color on the disc of the abdomen.
Some of the females have the abdomen nearly or wholly black. Specimens
of _A. obscuriventris_, Loew, have the body entirely black; the legs are
darker and the form is considerably smaller than _fuscitarsis_. Both
species are common at Columbus during May.
PTECTICUS (SARGUS) TRIVITTATUS, Say.
A species of _Ptecticus_ taken abundantly at Cincinnati by Chas. Dury
agrees so well with Say’s _Sargus trivittatus_ that I cannot convince
myself that it is anything else. Specimens when first taken agree more
closely with Say’s description than the same specimens do after they
have been in the cabinet awhile and have become dry. The green color
that Say mentions is present in some while others are yellowish or
brownish. The broad, dusky band that Say described as appearing on the
basal part of each abdominal segment beyond the second is conspicuous,
being of greatest extent on the fifth and sixth.
EUPARYPHUS MAJOR n. sp.
Female, length 9mm. Head yellow; vertex, a wide stripe from vertex to
mouth, widened at antennae and spreading out on the cheeks in the region
of the mouth, antennae and occiput, black; eyes hairy. Thorax shining;
apical two-thirds of scutellum including the spines, an irregular spot
each side between the scutellum and base of the wing, four longitudinal
lines abbreviated behind, a triangular spot before the base of the wing,
and two spots beneath it, bright yellow. There is also a minute yellow
spot on each side of the thorax posterior to the lower corner of the
eye, the yellow markings on the disc of the thorax extend for one-fifth
of their length behind the transverse suture, while those on the sides
extend from the humerus to the transverse suture. The femora except at
base and apex are black, and the last three tarsal joints are brown,
remaining parts of the legs are yellow; wings hyaline, veins dull
yellow, halteres bright yellow. Abdomen black; a spot under the
scutellum, a spot each side on the lateral part of the second segment,
an elongate oblique band nearly meeting its fellow of the opposite side
of each of the third and fourth segments, and apex, yellow. On the
venter the hind margins of the third and fourth segments are yellow for
their entire width, nearly the whole of the middle part of the second
segment and a narrow band on the posterior margin of the first segment
are also yellow. The lateral margins of the segments of the abdomen are
black between the yellow markings, and there is no connection between
the yellow markings on the abdomen.
A female specimen taken by E. J. Oslar at Boulder, Colorado, August 19,
1899.
In many respects this species agrees with Osten Sacken’s
_decem-maculatus_, but it cannot be that species as the markings are
very different. Aside from the hairy eyes it appears to belong to
_Euparyphus_. The third joint of the antennae is composed of six rings
with the last ring the longest. The fifth posterior cell meets the
discal and its general form agrees very closely with _bellus_ and
_tetraspilus_.