NOTES ON VARIOUS TRUCK-CROP INSECTS. 91 
plants. In the case above cited they were quite obviously injurious 
to the yam tuber, but the extent of the injury was not reported. 
Of the three species above mentioned EH. nitidiventris occurs in 
Texas and Florida; the other two are apparently not recorded from 
the United States. 
NOTES ON THE FEEDING HABITS OF BLISTER BEETLES. 
Entomologists have had occasion to notice, in the case of certain 
forms of insects, and more especially of gregarious caterpillars, that 
when once a colony begins feeding on a certain form of plant or other 
food, a special taste or fondness is developed by that colony and the 
insects continue on the same material, in the case of caterpillars, at 
least until about the last stage is reached. The same is observable 
in the case of leafhoppers, which frequently leave the plant on which 
they have fed during their first stages of growth and fly to another 
plant in the later stages. This habit is strongly developed in insects 
which are omnivorous as well as gregarious, e. g., in blister beetles. 
The margined blister beetle (Hpicauta marginata Fab.) has been 
repeatedly observed by the writer feeding on beets, literally in 
“flocks.”” The beetles begin at some point on a row or two and 
continue along those rows unless interrupted. When they are more 
abundant several colonies will frequently strip many rows until 
entire plantings are destroyed. Not until this is accomplished do 
they turn to some other food plant. Beet appears to be a preferred 
food plant of this species when it is available. On one occasion the 
writer observed this species attacking a row of cabbages contiguous 
to a row of beets. The beetles continued along this row, evidently 
“following the leader’’ like sheep. It is the same with weeds when 
these are attacked. On another occasion the beetles of this species 
were observed feeding on lamb’s-quarters—not a favorite food—and 
the flock continued on this plant until it left the neighborhood. 
The striped blister beetle (Hpicauta vittata Fab.) was seen in the 
same manner eating the rough pigweed (Amaranthus retroflexus), 
which the beetles almost completely defoliated, leaving nothing but 
the bare stems, and scarcely touching other plants occurring in their 
line of march. 
On such occasions the result is very much the same as though an 
“‘army’’ of army worms had devastated the tract attacked. The 
army worm supposedly assimilates a large portion of the actual food 
material which it consumes and which it requires for completing its 
growth. The blister beetles are already mature and judging from 
the large amount of excrement which they leave in their wake, con- 
sume many times as much as they actually require for sustenance. 
While it was the purpose of this note merely to mention the some- 
what peculiar habits of our eastern blister beetles, occasion is taken 
