41 
the autumn of 1864, Dr. Shimer ascertained that the spotted lady- 
bug (Hippodamia maculata) preys extensively upon the chinch-bug. 
In a particular field of corn, which had been sown thick for fodder, 
and which was swarming with chinch-bugs, he found, as he says, 
that this lady-bug ‘“‘could be counted by hundreds upon every square 
yard of ground, after shaking the corn; but the chinch-bugs were 
so numerous that these hosts of enemies made very little percepti- 
ble impression upon them.” In a corn-field near Jacksonville, vis- 
ited by me on the 7th of September, 1882, five species of iady-bugs 
were found extremely abundant on corn which was undergoing 
serious injury by hosts of chinch-bugs. There were often as many 
as fifteen or twenty to a hill, and larve were likewise occasionally 
seen. As they were found on all parts of the corn, traveling about 
actively among the bugs, the natural inference was that the latter 
attracted them to the field. Previous studies of the food of this 
family had shown me, however, that they were not by any means 
as strictly carnivorous as had previously been supposed, but that 
they often derived the principal part of their food from the veget- 
able kingdom. ‘To learn the exact state of the case in this corn- 
field, I collected a number of all the species seen there, including 
two larve, made careful dissections of a sufficient number of them 
to give me a fair average of their food, mounted the contents of 
their alimentary canals and examined them with the microscope. 
Three specimens of the common spotted lady-bug (Hippodanuia 
maculata) were dissected, but no traces of chinch-bugs were found 
in their stomachs, while all but about thirteen per cent. of their 
food consisted of the spores of lichens and various minute 
fungi, and the pollen of ragweed and other similar plants. 
Traces of plant-lice were recognized, undoubtedly derived from the 
common corn plant-louse (Aphis maidis), which also abounded in 
‘the field. Five specimens of the convergent lady-bug (Hippodamia 
convergens,) had eaten about equal quantities of plant-lice and chinch- 
bugs, which together made only one-third of their food, the remain- 
der consisting of the same kinds of vegetation as those just men- 
tioned. Three of these beetles, in fact, had eaten no insect food at 
all. To my great surprise, two larve of this species, taken at the 
same place and time, differed but little in food from the adults. 
Chinch-bugs and plant-lice in about equal ratios, with fragments of 
unrecognizable insects, made about one-fourth of the whole, the re- 
maining three-fourths consisting only of vegetation of about the same 
kinds as before. 
The icy lady-bug (Hippodamia glacialis) was represented by four 
specimens taken in this field. The differences between their food 
and that of the preceding species were purely trivial. Young chinch- 
bugs composed about eight per cent. of the total, and about eighteen 
per cent. was plant-lice. All the remainder was vegetation, divided 
about as before, between pollen of plants and spores of fungi. 
Lichen spores were also eaten freely, and were estimated at twelve 
per cent. of the whole. 
The nine-spotted lady-bug (Coccinella 9-ndtata) was represented 
by only a single specimen, which had taken no insect food what- 
ever, but had eaten only fungi. 
