1915] Collecting in Tachinide $1 
Professor Melander I made a very incomplete list of 23 
species among his duplicates. This gave me five lists, of which 
two were largely western and two eastern. 
The total number of species mentioned in these lists is 107; 
of these only 15 were mentioned in all the lists and seem 
therefore entitled to rank as the commonest Tachnids of 
the United States; 9 were mentioned four times, and hence 
may be considered as almost as common; 9 more were mentioned 
three times, indicating that they are fairly common; 24 were 
mentioned twice and 50 only once—these two classes have their 
periods of abundance, as many other species no doubt have, 
but are not generally or even frequently common. These 
indications are given as approximations only, conceding that 
further study of the matter would tend to increase the number 
of the common group. 
Taking them as they are, however, some rather striking 
facts about their parasitic relations will appear. I give a few 
notes about the first class, which occurred in all the lists: 
Cistogaster immaculata Macq. Adults are collected on 
flowers throughout the summer, and are in every collection. 
There is no trustworthy record of the rearing of this species, 
nor so far as I can find of its European congeners; its evident 
close relationship with the following species suggests the 
Pentatomide as its hosts. 
Gymnosoma fuliginosa R. D. Adults with the preceding, 
and equally common. Has been bred in Arizona from nymphs 
or adults of Pentatoma sayi, and again in New Mexico from the 
same host (the latter an unpublished record of the Bureau of 
Entomology). It lays an egg on the prothorax of the bug. 
Phorantha occidentis Walk. The most abundant of all 
Tachinide; I collected 328 specimens in 20 minutes on October 
23, 1914, by sweeping the flowers of Chrysanthemum leucan- 
themum near La Fayette. Nearly all my dated specimens were 
taken in September and October, and from flowers of compos- 
ites. It has been reared on September 11, 1913, by F. B. 
Milliken, from Nysius angustatus Uhler, one of the False 
Chinch Bugs (unpublished record). One of its European 
allies (Phasia hemiptera) attacks adult beetles, inserting an 
unincubated egg by means of a sharp ovipositor. Occidentis is 
probably a single-brooded species. 
