16 
outward manifestation of attack. When the insects are present in the 
field it is often stated that the plants are ‘‘blighted.” The diseases 
of potato, particularly one caused by bacteria, are apt also to be mis- 
taken for the work of the weevil, as in both cases the leaves look as 
if sunburned, particularly after the vines have been affected for some 
time. Not infrequently the field will be found to suffer from the com- 
bined effects of dry weather, disease, and stalk weevil. To detect the 
presence of the weevil it is only necessary to cut open the infested 
stalks, when the insect will be found in some stage in the pith. The 
weevil’s presence is generally shown first in the withering of the lower 
branches, but in dry, hot weather the whole plant may be affected. 
The beetles feed on the leaves of potato and other Solanacez, but 
do no appreciable injury in this stage. 
This insect attacks, in addition to potato, nearly all of the Solanaceze ~ 
growing wild within its natural range. The list of food plants includes, 
besides potato, eggplant (Solanum melongena), horse nettle (S. caro- 
linense), bull nettle (S. rostratum), jimson weed (Datura stramonium), 
purple thorn apple (2. tatula), ground cherry (Physalis longifolia, 
philadelphica, lanceolata, heterophylla, and virginiana vay. ambiqua). 
According to Faville and Parrott this insect also attacks cocklebur 
(XNanthium canadense). Tobacco and tomato appear exempt. 
The presence of a single larva in a potato stalk is not sufficient to 
injure it to any extent, although it must have a weakening effect, but 
when many larve occur in the same stalk destruction is complete. As 
many as 5 or 6 individuals may sometimes be found in a potato stalk, 
and 8 have been observed in the stems of a ground-cherry plant. 
LIFE HISTORY. 
The beetles have been observed in the vicinity of the District of 
Columbia as early as May 20 on wild Solanum and Datura, which at 
that time were only 2 or 3 inches high. It seems probable that the 
beetles seldom put in an appearance earlier than the middle of May, 
as the plants are scarcely far enough advanced before that time for 
food. Pairing was noticed a few days afterwards, and oviposition 
probably begins normally before the end of the month of May, although 
farther north it does not commence until June. The female weevil 
deposits her eggs singly, in small slits or holes about one-twelfth of an 
inch in length, made in the stalks of the insect’s food plants and occa- 
sionally in the branches. In about a week or ten days. according to 
temperature, the larva hatches from the egg and begins to feed by 
making small channels, which increase in size with the growth of the 
insect, downward toward the bases of the stalks. After working down- 
ward for a distance—usually to the roots—the larva turns about and 
begins the enlargement of the old channel fora portion of the way 
upward. The undermining of a stalk by the tunneling of several 
