THE GENUS ZONOSEMATA , WITH NOTES ON THE 
CYTOLOGY OF TWO SPECIES 
( DIPTERA — TEPHRITIDAE) 1 
By Guy L. Bush 
Department of Biology, Harvard University 
The genus Zonosemata (Trypetinae, Trypetini) was established 
by Benjamin (1934) to include the type, Trypeta electa Say, and 
Zonosema vittigera Coquillett. The latter species he considered as 
possibly only a western race of electa. Both are recognized as distinct 
in this revision and two new species from Mexico and one from 
Jamaica are described. 
Zonosemata is closely related to the Holarctic and Neotropical 
Rhagoletis Loew (including Zonosema Loew), the monotypic 
Nearctic Rhagoletoides Foote, the Neotropical Rhagoletotrypeta 
Aczel, and the Palearctic and Indian Carpomyia Rondani 2 . It shows 
particularly close affinities in habitus to certain Mexican and Neo- 
tropical Rhagoletis , such as R. striatella, R. ferrugineus, R. ly co- 
per sella, R. ochraspis, and others, some of which infest solanaceous 
fruits as do at least two species of Zonosemata. Cytologically the 
chromosomes of Zonosemata also bear some resemblance to those of 
R. striatella. Furthermore, unlike other Rhagoletis species, the egg 
of striatella is stalked and somewhat like those of Z. electa (Fig. 26) 
and Z. vittigera. These similarities, coupled with the fact that four 
of the five species are from Mexico and Jamaica, suggest that Zono- 
semata probably originated in Central or possibly South America from 
some common ancestor with Rhagoletis. Further field work in these 
regions may therefore eventually clarify the relationships between 
these two genera. 
BIOLOGY 
The biology of Z. vittigera and Z. electa has been discussed in 
some detail by several authors (Peterson 1923, Benjamin 1934, Bur- 
dette 1935, Cazier 1962, and Foott 1963). Both species normally 
infest certain native species of horsenettle ( Solanum spp., Solanacece) . 
’Published with the aid of a grant from the Committee on Evolutionary 
Biology, Department of Biology, Harvard University. Manuscript received 
by the editor, August 30, 1965. 
The presence of minute ocellar bristles in Carpomyia is the only character 
that effectively separates this genus from Rhagoletis. This character is of 
doubtful importance and Rhagoletis may eventually fall into synonymy 
with Carpomyia (for detailed discussion see Bush 1966). 
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