138 College of Forestry 
ited as to make it unwise to deduce more than rather general 
conclusions. Thus we can say that Pangonia tranquilla is 
most abundant in the Elka Park region when the blossoms 
of wild spireea are at their maximum, which in 1917 was 
during the first half of August. Similarly we may say that 
Spilomyria fusca begins to appear at about the same time 
but does not reach its maximum numbers until the spirsea 
blossoms are decidedly on the wane. This species then, does 
not appear until Vespula marginata and other similar black 
and white hornets of which it is a mimic, are becoming quite 
numerous, and does not reach its maximum numbers until 
these hornets are the most abundant flower visitors. The very 
striking resemblance of the fly and hornet can but be 
admitted by anyone who has collected both from the same 
flowers. 
IT am under obligations to Prof. A. S. Hine of Ohio State 
University for his kindness in identifying the flies in the 
above table. 
In addition to the various Coleoptera, Hymenoptera, 
Hemiptera and Diptera which are listed in the accompany- 
ing table a considerable number of insects belonging to other 
orders were observed on spirza blooms. Doubtless the major- 
ity of these were casual visitors which would be no more 
likely to be found on blossoms than on any other structure 
occurring in the same location. This is certainly true of 
several species of dragon flies, grasshoppers, katydids, caddis- 
flies, ete. In addition to these, several moths and a number 
of butterflies were seen upon spirea blossoms, but no effort 
was made to obtain quantitative data of any of these. The 
following butterflies were observed upon the blossoms of 
spirea: Papilio turnus Linn, P. polyxenes Fabr., Feniseca 
tarquinius Fabr., Basilarchia arthemis Drury, B. astyanax 
Fabr., B. archippis Cram., Grapta progne Cram., Argynnis 
cybele Fabr., and Hrynnis sp. The moths taken are fewer 
in number of species and include Hemorrhagia diffinis 
Boisd., Lycomorpha pholus Drury, Ctenucha virginica 
Charp., Synanthedon bassiformis Walk., S. acernt Clem., 
and Ozxyptilis sp. These moths apparently were on the 
