JOINT WORM FLIES. 17 
stems in New York in 1888. It is supposed that captiva was the 
species involved in the latter case, but doubt is cast upon this sup- 
position by Lintner's statement that part of the specimens were 
typical hordei (tritici), and part were much larger, the latter being 
captiva. The species the writer knows as captiva is much smaller 
than tritici; besides, captiva has been reared from galls in blue- 
grass, and should it breed in wheat also it will be the second species 
known to infest plants belonging to separate and distinct genera. 
This is not at all impossible but at present it seems improbable. 
As the New York case is the only one recorded where the species 
has been reared from wheat it seems reasonable to suppose that 
another species than captiva was involved. 
The writer reared specimens of captiva from galls in blue-grass 
collected near Eichmond, Ind., in 1905. It has not been reared 
since. Nothing is known of its life history except that it un- 
doubtedly has only one generation a year and that both males and 
females were reared. The galls (PI. Ill, D) occur near the base of 
the seed stalk where the stem is thick. As the seed stalks of blue- 
grass are slender and rather frail the stem at the point where the 
galls occur does not seem to be very woody. The cells are arranged 
in a row end to end, there being insufficient room, apparently, for 
the larvae to have cells side by side in the stalk as in some other 
species. 
THE BLUE-GRASS STRAW-WORM.* 
The blue-grass straw-worm was described only recently by the writer 
and W. T. Emery (10, p. 445) but undoubtedly has been breeding in 
blue- grass (Poa pratensis) for years. Very probably it has been 
confused with H. captiva and perhaps with other species. The first 
records of poae are by F. M. Webster and the writer in 1905. It is 
a widely distributed species and doubtless can be found wherever 
blue-grass grows normally. 
MANNER OF INJURY. 
The writer has never had the opportunity to visit sections that 
grow blue-grass seed to learn to what extent infestation exists. The 
only infestation found has been where the grass grows wild in pro- 
tected places, such as along fences. Pastures usually are kept cropped 
close by stock and there is little chance for poae to breed. It works 
in the center of the stem and undoubtedly would injure the seed 
crop greatly, as the seed stalks of blue-grass are slender, soft, and 
rather fragile, not at all hard and woody like the majority of the 
grasses affected by other species. The cavity in the stem is scarcely 
1 Harmolita poae Phillips and Emery. 
