~ 
Or 
1917] Hungerford—Life-History of Mesovelia mulsanti White 
HaBpitat AND Foop Hasits. 
It has been indicated above that these little bugs live upon the 
floating vegetation of ponds. Butler (2) found them on Potamo- 
geton and Bueno (1) 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 leaves and stems of plants pro- 
cumbent upon the surface. 
They were noted by Butler to be carnivorous in tastes. He fed 
them a variety of small insects and saw them feeding upon a 
springtail, (Smynthurus), a Crambus, a Chalcid and a Hydrometra 
and supposed 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 prey, as evidenced by the following instance: A fly thrown 
into the aquarium was seen to crawl up the side of the jar bearing 
an adult female Mesovelia with its beak attached near the caudal 
end of the fly which when disturbed flew to a nearby support 
bearing the tenacious little bug. 
However, the writer has come to believe that, with Hydrometra, 
Microvelia and Rheumatobates, they are not dependent upon the 
chance and uncertain fare of terrestial insects caught upon the 
surface film but find another, and indeed a more constant source 
in the organisms that dwell below but come up to the surface film. 
Among these, Ostracods and like forms are available as more or 
less staple food and Mesovelia have been observed exploring the 
sides of floating Typha and the tangled mats of alge for such 
Crustacea which they spear from the surface of the water. 
The tiny nymphs feed upon more gentle organisms in the water, 
as there are few upon the surface that they are able to overcome. 
When offered springtails as suggested by Butler, disaster often 
followed and the writer lost many good rearings before he learned 
the inadvisability of offering such food. The hungry little crea- 
tures would attack them only to be turned topsy-turvy upon the 
water even by comparatively small springtails. Plant lice afforded 
