12 
THE PAN-PACIFIC ENTOMOLOGIST 
Stenotabanus (Aegialomyia) yaquii Philip 
When this surprising beach-inhabitant on the western coast of 
Mexico was described recently, an important, pertinent male from the 
coast farther south was overlooked in a collection of Mexican horse 
flies received some years ago from Mrs. Reginald H. Painter of 
Manhattan, Kansas. It is here described as neallotype of the typical 
form because of the entirely red antennae including styles. 
Neallotype male. Length 10.5 mm, a little larger than the type female from Sinaloa, the 
antennal plates, as usual in males, a little narrower, and the palpi subovoid, half again 
longer than thick. The upper, pale yellow, enlarged facets are bare, occupy the upper 
three-fourths of the eye area, and are somewhat rolled over the occipital margin behind; 
lower small facets sharply black. Wing venation, reddish legs and halteres as in the 
female, but the body is paler grayish, the pattern of small, double-paired spots more 
obscure. 
Locality: Mexico: Colima, 4.5 km NW Manzanillo, 26.viii.62, R.H. & E.M. Painter, colls. In 
California Academy of Sciences, no. 13038. 
While this was collected even south of Nayarit where the types of 
S. (A.) yaquii subspecies occidentalis Philip were taken, the question 
still remains of whether intergradation will eventually be found 
between the 2 forms. More collecting along western beaches in 
Mexico, possibly in the vicinity of mangrove (as in the case of S. (A.) 
littoreus (Hine) on the eastern Gulf Coast), should provide more 
adequate series of both sexes, to decide if these characters are 
plastic and subject to variation. 
The males of related magnicaiius Stone and pechumani Philip of Gulf 
Coast of Mexico lack evidence of any abdominal patterns in unsoiled 
specimens, and, though the distribution of enlarged eye facets is 
about the same in the former, the palpi are more pointed and the 
flagella brown to black apically; in pechumani, the male eyes are very 
narrowly separated mesally, and upper facets less enlarged, more 
restricted, and the flagellum mostly black. 
Both sexes of yaquii bear considerable resemblance with their all- 
red antennae to S. (A.) littoreus (Hine), particularly from mangrove 
beaches on the Atlantic Gulf Coast from Quintana Roo, Mexico, to 
Panama; littoreus, however, are more brownish overall, the scutellum 
reddish. The male, especially, of yaquii is a much grayer insect with 
darker thoracic integument underlying the pale gray pollenosity, 
including the scutellum. The eye pattern was only faintly revived in 
one of four eastern littoreus, but it appears to resemble that in yaquii, 
namely, two green stripes on a purple ground. 
Teskeyellus hirsuticornis Philip and Fairchild 
The describers of this peculiar, Mexican tabanid, considered its 
systematic relationships as “unclear,” but believed it “belongs in the 
more primitive section of Diachlorini with Dasybasis and 
