hungerford: aquatic hemiptera. 101 



angulam apicalem interiorem membranae 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 algae 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 algse 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 Potamogetpn and Bueno on duck-weed, 

 matted Hydrodictyon or other algse. 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 algae 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 

 n>Tnphs 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 (Sm>-nthurus), 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. 



They are cautious creatures, but do on occasion fall upon fairly 

 lively pi'ey, as evidenced by the following instance: A fly thrown into 



