level, although the rain forest has 
been sparsely colonized. 
In the United States, the Agromyzidae 
are present in all States but unevenly 
distributed. Detailed surveys have 
been made in Florida (Spencer and 
Stegmaier, 1973), where 86 species 
have been recorded. In California 
(Spencer, 1981), the number is 
substantially larger, with 252 
species, reflecting its diverse 
geographical and climatic conditions. 
Little collecting has been undertaken 
in the Northern States, such as Maine 
and the Dakotas, but from the few 
records available from Michigan, 
Minnesota, Montana, and Wisconsin, the 
family is well represented in all 
northern areas. Our collecting in 
Mississippi and Arkansas has suggested 
that relatively few species are 
present there, comparable to the 
limited fauna in Florida, but leaf 
mines have recently been found on many 
hosts in Texas by S. Tavormina, 
although no undescribed species were 
discovered • 
During our research, approximately 700 
specimens were examined from high 
elevations in Colorado, particularly 
from the Mt. Evans area up to the 
summit at 4,260 m (14,200 ft). Many 
species were found there, but unfortun- 
ately not a single species was reared 
and the hosts remain unknown. From 
the small amount of material seen from 
the Western States, including Idaho, 
Utah, New Mexico, and Arizona, there 
is clearly a rich, largely unexplored 
fauna, and many undescribed species 
can be expected in these States. 
A notable fact that has emerged during 
our study is the wide distribution 
within the United States of most 
genera and many individual species, 
both from east to west and north to 
south. Details are given under the 
genera concerned, but some striking 
examples may be cited here. 
Melanagromyza buccalis occurs from New 
York to California and M. lippivora , 
described from Florida, is synonymous 
with M. riparella from Illinois. 
Ophiomyia texana occurs from Ontario 
to Texas, Liriomyza lathyri was 
discovered in Arkansas, previously 
known only in Alberta, and in an area 
of relict forest in Mississippi a 
large population of Phytomyza 
penstemonis was found, previously 
known in Alberta and California. Con- 
versely, many species have a more 
restricted distribution. Many of 
neotropical origin appear to be 
limited to southern Florida. The 
important pest species L. huidobrensis , 
which is common in California, is 
absent from Florida and other south- 
eastern States. 
Several high-elevation species pre- 
viously known in the Sierra Nevada and 
farther north in Canada or even Alaska 
have been confirmed in Colorado. 
There does, however, appear to have 
been some speciation on either side of 
the Sierra Nevada, but the true distri- 
bution of such species requires further 
investigation with additional col- 
lecting. 
About 200 species are known in Canada 
and Alaska, but not yet in the United 
States. A considerable proportion of 
these may be found in the United States 
when the family is better known. 
Despite the clearer concept of the 
distribution of Agromyzidae in the 
United States, our knowledge is still 
fragmentary. Specialized collecting 
in all areas will produce more State 
records of known species, and certain- 
ly many undescribed species await 
discovery. 
REARING AGROMYZIDAE 
Many adults can be caught by general 
sweeping, but the most satisfactory 
method is to rear them from larvae or 
puparia that can be found on their 
host plants. Frick (1951c) outlined a 
technique he employed in rearing 
Agromyzidae in California. The notes 
given here somewhat modify and elabor- 
ate on his procedure. 
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