Notes on Insectivorous Coleoptera. 
175 
Hippodamici convergens. — A specimen, captured in 
August, at Normal, had eaten great quantities of fungus 
spores, which composed about three-fourths of its food. 
Fragments of a mite and a plant-louse and a little pollen 
of Composite were also found. In a second specimen, 
taken in September, the remains of a myriapod belong- 
ing to the family Geopliilidae, acrospores of a fungus, the 
pollen of Composite and the remains of a plant-louse 
were the only elements noticed. 
Megilla maculata . — Three specimens of this species 
were dissected — one received from Mr. Webster in May, 
one from Mr. McBride in July, and one taken at Normal 
in September. The specimen from Mr. Webster was cap- 
tured on the flowers of dandelions. Its entire alimentary 
canal was closely packed with hexagonal, spinose pollen 
cells, doubtless taken from that plant. A second had 
eaten the anthers and pollen of grass with a few spores 
of Myxogastres.* The third specimen contained pollen 
and fungus spores in about equal quantities. While these 
Coccinellidae had made good their usual reputation as 
enemies of plant-lice, it should be noticed that these con- 
stituted only about ten per cent, of their food. 
If these specimens of the various families of preda- 
ceous beetles are fair examples of their class, the above 
facts imply that the individual carnivorous insect is 
much less valuable than has usually been supposed, while 
predaceous insects as a class are much more beneficial. 
If these species are predaceous, as a rule, not more than 
from one-fourtli to one-third of the time, the injury done 
by the destruction of one of them is very much less than 
if they were, as is usually supposed, almost wholly car- 
nivorous. But, on the other hand, if they can live on the 
soft parts of plants when animal food becomes scarce, 
their numbers will be maintained at a far higher figure 
than would be possible if they were dependent upon ani- 
mal food alone. Preferring animal food to vegetable, as 
they doubtless do when equally obtainable, they operate 
as a much more effective check on the undue increase of 
other insects than if their number were at all times strict- 
* Burrill. 
