HUNGERFORD: AQUATIC HEMIPTERA. 101 
angulam apicalem interiorem membrane currente et membranam a clavo 
separante, instructa, (membrana interdum obsoleta); corpore subtus 
albido-testaceo, albo-piloso. 
“Long. 4 mm.” 
B. BIoLoGy oF MESOVELIA. 
General Notes. Since there is probably but the one species of the 
genus in America, any. discussion of the general habits must be based 
upon the two species observed. They are small insects, that measure but 
four or five millimeters in length. The young and apterous forms of 
the adult display varying degrees of green coloration, while the winged 
ones are quite conspicuous in the floating blankets of green alge because 
of the silvery whiteness of their wings. 
They are at home in the haunts of the marsh-treader, on the floating 
vegetation growing in the shallow water of pools, where the clumps of 
sedge spread their slender stems upon the water from the bordering 
bank, where young cattails spring up and green alge carpet the surface 
of the waters. 
The information concerning the biology of these forms is meager and 
confined to a paper by Butler, 1893, on the “Habits of Mesovelia furcata,” 
collecting notes on M. furcata by J. Scott in England, and on the bisig- 
nata (Mulsanti) by Uhler and by Bueno in this country. The writer 
published a paper in Psyche for June, 1917, from which most of the 
facts here presented were gleaned. 
Habitat. Mesovelia mulsanti lives upon the floating vegetation of 
ponds. Butler found them on Potamogeton and Bueno on duck-weed, 
matted Hydrodictyon or other alge. The writer has found them about 
old logs projecting from the water, clumps of smartweed at the water’s 
edge, as well as on rafts of filamentous alge and the leaves and stems 
of such plants as water shamrock, procumbent upon the surface. 
Hibernation. Direct evidence upon this point is lacking, for in winter 
collecting at Ithaca, N. Y., none were taken. On November 8, 1916, on 
a trip to Ringwood Hollow, in company with Mr. Lloyd and Dr. and Mrs. 
Needham, two apterous adults were taken by the writer beside a large 
_moss-covered log lodged in the shallow waters of the winter-berry pool. 
This would indicate that they winter as adults. They did not come to 
the writer’s attention till May 25, 1916, at which time the green scum 
of Cattail pool, near Lawrence, Kan., was swarming with hundreds of 
a ne Se 
nymphs just coming to the adult stage. These appeared to be the 
progeny of over-wintering bugs. 
Food. They were noted by Butler to be carnivorous in tastes. He 
fed them a variety of small insects and saw them feeding upon a spring- 
tail (Smynthurus), a Crambus, a Chalcid and a Hydrometra, and sup- 
posed the usual food to be small Diptera and Hymenoptera. As to 
whether they caught their prey alive or availed themselves of the 
_ drowned and disabled specimens he was unable to say. That M. mulsanti 
can live upon such fare is certain, for the writer has reared them on 
_ flies and plant lice cast upon the water. 
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They are cautious creatures, but do on occasion fall upon fairly 
lively prey, as evidenced by the following instance: A fly thrown into 
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