A New Genus and Five New Species of Scatopsidae from California, 
Mexico, El Salvador and Peru 1 
(Diptera) 
Edwin F. Cook 
Department of Entomology, Fisheries and Wildlife, University of Minnesota, St. Paul, 55108 
Material sent to me for identification in 1977 from the California 
Academy of Sciences by Paul Arnaud contains a new species of 
Swammerdammella, a new Psectrosciara and an additional species 
that necessitated a reexamination of two species included in my 1956 
paper as the dampfi complex in Rhexoza. The reexamination has 
required the erection of a new genus, below. In addition 2 species 
from an earlier California Academy of Science loan are described as a 
new species of Rhegmoclemina and a new species of Colobostema. All 
are from California, Mexico, El Salvador and Peru. 
When I reviewed the genus Rhexoza in 1975 I deliberately ignored 
the two species included in the group I had termed the dampfi 
complex of Rhexoza in 1956. This was because these were 2 rather 
different species, and while they fit in the tribe Swammerdamellini 
they both differed in characteristics that I considered necessary for 
inclusion in the described genera making up that tribe. The discovery 
of a new species very near R. dampfi (Duda) has prompted me to erect 
a genus for these two species. Rhexoza cryptica Cook, originally 
placed with R. dampfi, must be placed in Swammerdamella despite the 
fact that it lacks the “key” character for inclusion in that genus. 
Segment 7 is not concealed in segment 6 in the male and tergum 7 is 
differently modified (see Cook 1956, Fig. 5D). Aside from this, it has 
identical head structure, maxillary palp form, chaetotaxy and genital 
vesica and apodeme size. The wing venation and antennal structure 
are like S. pygmaea (Loew). There is also an aedeagal plate in the male 
which I overlooked in my earlier description in addition to the 
posterior median process. 
Akorhexoza, new genus 
Antennae 10-segmented (8 flagellomeres) slightly longer than height of head capsule; 
cardo-stipites broad, band-like, fused mesally and setose; maxillary palpi large, rather 
reniform; proboscis nearly as long as head capsule height; label la elongate, rather 
slender; occiput sparsely setose posteriorly, very few microtrichia only near foramen; 
eyes with setae between facets. Thorax with triangular spiracular sclerite, longer than 
‘Paper No. 10,060 Scientific Journal Series, Minnesota Agricultural Station, St. Paul, 
Minnesota. 
The Pan-Pacific Entomologist 54:31-37. January 1978 
