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The taxonomic significance of the male genitalia and associated structures in the genus Eucerceris cresson (Hymenoptera : Sphecidae)

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Title The taxonomic significance of the male genitalia and associated structures in the genus Eucerceris cresson (Hymenoptera : Sphecidae)
Names Davidson, Jerry Mitchell (creator)
Ritcher, Paul O. (advisor)
Date Issued 1970-04-27 (iso8601)
Note Graduation date: 1970
Abstract The male genitalia of 69 species, representing eight genera of
sphecid wasps, were examined in order to ascertain their taxonomic
value. In all, the male genitalia of approximately 1000 specimens
were critically studied.
Emphasis was placed on the genitalia and associated sclerites
of the known males in the genus Eucerceris. The genitalia of most
species are so different that they can be defined by this structure
alone. The pygidia, and to a lesser extent the seventh and eighth
sterna, also offer reliable characteristics with which to distinguish
species. The North American genera of the subfamily Philanthinae
can be differentiated on the basis of male genitalic morphology.
The morphology of the male genitalia of Eucerceris indicates a
close relationship with Cerceris. This relationship is also indicated
by external non-genitalic morphology. The genitalia of Didesmus
males are radically different from those of Cerceris and Eucerceris
but nevertheless, Didesmus is most closely related to these genera on
the basis of non-genitalic characters,
The male genitalia of the philanthine genera Aphilanthops,
Clypeadon and Listropygia are very similar but differ considerably
from those of the cercerine genera Cerceris, Eucerceris and
Didesmus. These differences and similarities support the presently
accepted classification and placement of these genera. Based on
genitalic characters, Philanthus and Trachypus appear to be closely
related to each other. On the basis of external non-genitalic characters,
however, these genera appear to be only distantly related.
Without examining other genera from Africa, Asia and South America,
determination of the relationships of Philanthus and Trachypus to
other groups is not possible.
A key to the genera and a key to the species of Eucerceris based
on male genitalia are provided. In addition, the genital structures of
33 species of Eucerceris are described in detail and the major key
characteristics illustrated.
Genre Thesis/Dissertation
Topic Wasps
Identifier http://hdl.handle.net/1957/46203

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