— 82— 



sist in the poUenization of the flowers, as I have watched them 

 working many hours; Eristalis tenax is the name it received Irom 

 an entomological friend." 



Reports from other sources are to the same effect, but no one 

 has yet volunteered the statement that of his own knowledge seed 

 has been so obtained, and it has been considered indelicate to put 

 the question directly to the producers of this precious commodity; 

 an experiment, however, would be no way difficult. 



Eristalis tenax is an inhabitant of the old world, and accom- 

 modates itself to all climates from the Arctic regions of Siberia to 

 the tropics in Africa, probably originating in Japan, the metropolis 

 of Chrysanthemums. The knowledge of its existence in N. America 

 dates back no further than 1875, when Baron Osten Sacken took a 

 single specimen at Cambridge, Mass., after having collected Diptera 

 throughout the United States, and yet, in 1884, it was known from 

 nearly all parts of the country, from Massachusetts to Georgia, and 

 westward to Washington. (Psyche ii, 188 and 260; Can. Ent. xiii, 

 176; Trans. Ent. Soc. London, 1884, p. 489-96). In the last cited 

 article Baron Osten-Sacken, speculating on the mode of its intro- 

 duction into North America, and its sudden appearance all over the 

 country, states the only two possible ways. . First, by introduction 

 through the Atlantic seaboards; he fails, however, to inform us how 

 this insect was likely to have been so extensively distributed in eight 

 or nine years. Second, as being indigenous to Western, but not to 

 Eastern America, it slowly worked its way across the Rocky Moun- 

 tains eastward to Missouri, where, meeting with more favorable con- 

 ditions, like Doryphora decemlinenta, it suddenly spread to the At- 

 lantic, where it was soon recognized by entomologists; but what 

 these conditions were is not indicated. 



Now, we may have it from both sources, as it is indigenous in 

 Kamtschatka it may also be in Western North America, like so 

 many other insects. And we may likewise have it by introduction, 

 and if it really escaped commercial transportation, though seemingly 

 strange considering its larva and imago habits, till near the time 

 specified, its subsequent rapid and wide distribution is not incredible 

 nor impossible when. its relation to Chrysanthemums is considered, 

 the craze for which during the last two decades has spread them to 

 nearly every village and farm house in the United States. In the 

 article cited above from the Can. Ent., Dr. S. W. Williston states 

 that this fly is often found ' ' in houses early in October. ' ' Chrys- 

 anthemums, probably, might have been found there likewise. 



No record of the food-habits of the mature E. tenax has been 

 noticed; it cannot, however, be confined to greenhouse Chrysanthe- 



