10 
black, and there are three black impressed spots at the base of the 
elytra or wing covers — one scutellar and two lateral — from which the 
insect has derived its Latin name, trinotata. The rostrum or snout is 
robust and rather strongly curved, and the antennae, like those of other 
Curculionids, are elbowed and clubbed at the ends. The body is oval 
and somewhat depressed or flattened above. The male is credited with 
being generally larger than the female — something rather unusual in 
insects. The length is about one-sixth of an inch (3 to -±.5™ m ) and the 
width less than half that (1.2 to 1.75 mm ). 
The beetle is shown in the accompanying 
illustration (fig. 1, a). 
The egg is of the usual white color and 
oval form seen among the Rhynchophora, 
and, according to the measurements of 
Faville and Parrott, is about 0.6 mm in 
length and 0.4 mm in width. 
The larva, or grub, as it appears when 
first hatched from the egg, does not ap- 
pear to have been described. It is, how- 
ever, whitish at this stage, and without 
feet. When full grown it is remarkably 
elongate in form, about eight or nine 
times as long as wide, with small circular 
pale-brown head, the whole having the 
appearance shown at l (fig. 1). It reaches 
a length of about two-fifths of an inch 
(9 to ll mm ), and is only moderate^ curved when in natural position in 
the stems. Instead of legs these larva? are provided with feebly defined 
thoracic leg pads. The color at this, as in the pupal condition, varies 
from nearly white to rather bright yellow, the color in one instance, 
in an individual taken from the root stem of Solanum carolinensis, 
being of a decidedly rosy or light pinkish hue. 
The pupa looks like that of other weevils, and presents no very 
noticeable features for description. A ventral view of a papa is .shown 
at c (fig. 1). At d a larva and pupa are figured natural size within an 
opened stalk of potato. 
Fig. 1. — Trichobaris trinotata: a, beetle; 
6, larva from side; c, pupa; d, section 
of potato stalk opened to show larva 
and pupa in situ — a, b, e, five times 
natural size, d, natural size (original.) 
DISTKIBUTION. 
The potato stalk weevil is rather generally distributed throughout 
the Carolinian and Austro riparian regions. Northward the limit of 
injurious occurrence was reached in Pennsylvania and New Jersey in 
the East, and in Illinois and Iowa in the West; recently, however, the 
species has become a pest in Canada. Southward the insect is found 
to Florida and westward to Texas. A list of localities follows: 
Titusville, Little Silver, Freehold, Hopewell, New Brunswick, and Trenton, X. J.; 
Yorkana, Germantown, Westchester, Pawling, Philadelphia, Allegheny, and Pitts- 
