THE MAIZE BILLBUG. oF 
Elytra little wider than the thorax; striz usually deep and well defined, 
distinctly closely punctate; intervals with first, third and fifth elevated, with 
two or more series of rows of fine punctulation; first or sutural with basal 
third triseriately, posterior two-thirds biseriately punctulate; third widest and 
most elevated, with four or five rows of fine punctulations; fifth biseriately 
punctulate; seventh little or not at all more elevated than the remaining inter- 
vals; intervals 2, 4, 6, 8, as also 7, more coarsely and closely uniseriately punctu- 
late. Pygidium deeply, coarsely and rather sparsely punctate, with sparse 
golden yellow hairs proceeding from the punctures and forming a short tuft 
each side, frequently abraded. 
Lower surface coarsely and rather densely punctate, scarcely less strongly 
at the middle than at the sides, punctures largest at the middle of the meta- 
thorax. Punctures of the metepisterna (side pieces) more or less confluent, 
Second, third and fourth abdominal segments 
nearly uniformly punctured throughout, like 
the legs. 
é.— First abdominal segment very con- 
cave; pygidium truncate at apex. 
2 .— First ventral scarcely different ; pygid- 
jum narrowed and rounded at apex. 
Aside from the differently shaped pygidium 
and the slightly shorter and less compressed 
rostrum there is little difference between the 
sexes, 
Length, 10-15 mm., width, 4.5-6.0 mim. 
The adults begin to issue about the 
middle of August and continue to do so 
until the middle of September. Some 
of them leave the pupal cell, but most 
of them remain there for hibernation. 
The adults that leave the pupal cell in 
the late summer disappear; continued — Fic. 10.—The maize billbug: Adult. 
search in every situation until Decem- gaan ale 
ber failed to reveal a single individual. ca 
It is evident that they left the cornfield in which they developed, 
and it is very probable that they found their way to some dense, 
coarse grass (7. dactyloides), which is abundant in the locality, 
The adults hibernating in the pupal cells issue from them in late 
spring, about the time young corn is sprouting. The beetles are 
rarely observed on account of their quiet habits and because they 
are covered with mud—a condition which is more or less common 
among several species of this genus and is caused by a waxy exuda- 
tion of the elytra, to which the soil adheres. The presence of the 
adults of this species in a cornfield is made evident by the withering 
of the top leaves of very young corn plants. the plants having been 
severely gouged. The adults kill the small plants outright and in- 
jure the larger ones beyond repair. After the plants grow 10 to 15 
inches tall they do not kill them, but gouge out such large cavities 
in the stalks that they become twisted into all sorts of shapes (PI. I, 

