158 SIXTEENTH BIENNIAL REPORT 



Host Plant List of Larvae — Root System 



Grass (Poa cerotine) 



Timothy 



Bluegrass 



Potentilla glandulosa 



June grass 



White clover 



Description 



The Adult Weevil is a snout beetle, 6 mm., or nearly one-fourth of an inch in 

 length. The cokir of the insect varie.s from a dull reddish brown when freshly 

 emerged to almost piteh black ; the surface is roughly pitted and slightly shiny. 

 The beak is short, broad and emarginate at the tip ; there is a distinct puncture 

 between tlie eyes. Tlie antennae are elbowed and consist of nine Segments. The 

 proximal segment is set in a pit ; it is elongate. finely haired with light yellow 

 fluff, slightly curved and enlarged toward distal end to form the socket of the 

 elbow Joint. The next seven Segments are bead-like with coarse dark hair. The 

 distal segment forms an ovate knob and is finely haired the same as the proximal 

 segment. The thorax is nearly globular, tnberculate, pitted and coarsely grooved. 

 Each tubercle bears a short hair. The body behind the thorax is oval, the Striae 

 more uniform. There is a distinct, narrow, dark shining ring between the thorax 

 and body proper. The femur of each leg bears a spur. The beetle is without 

 wings, but with elytra very hard and securely grown together. Upon removing 

 the elytra, rudimentary wing pads are found still present. 



The Egg is about .55 mm. in length and about .29 mm. in width. It is milky 

 white with pronounced translucence when first deposited, later changing to a 

 dirty yellowish I)rown. It is smooth when first deposited, but indentations soon 

 appear, and by the time it has assumed the darker color it is deeidedly rougliened. 



Larva — The length of the larva at the time of liatching is .75 mm., the breadth 

 of the head during the first instar, .24 mm. 



Weed describes the larva and pupa as follows : 



"Larva — All of the larvae which were seen eating were of a pinkish tinge, but 

 when compelled to fast, became white. The full-grown larva is three-eighths of an 

 inch long by one-eighth of an inch wide; white, except the head, which is light 

 brown, with the mouth parts darker and the edges of the jaws black. The head 

 is smooth except for four transverse rows of light brown hairs. The body is 

 arched ; on each segment is a row of reddish brown hairs, curved at the tip on 

 the back, but shorter and not curved on the under side. The dorsum or upper 

 part of each ring is divided into three transverse lobes or folds, all except the 

 first and the next to the last of which are smooth. On the under side of the first 

 three Segments are tubercles in place of feet ; these possess stiff hairs. On the 

 sides of each segment are two triangulär tubercles, each beariug two hairs, one 

 of which is but half as long as the other. A longitudinal fissure separates the 

 Upper row of tubercles from the lower. 



"Pupa — When first transformed. tlie pupa is pure white, three-eighths of an 

 inch long by two-eighths of an inch wide. The head and snout are beut against the 

 breast, the latter not quite twice as long as wide, tapering sliglitly toward the 

 tip, the jaws plainly visible. The elbowed antennae extend to the base of the wing 

 cases ; the abdomen terminates with a pair of incurved hooks. On each segment 

 of the head and thorax is a transverse row of spinous, reddish brown hairs termi- 

 nating by recurved hooks. On the outer end of each femur (thigh) is a pair of 

 similar spines, the inner liut half as long as the outer. On each segment of the 

 abdomen is a transverse row of reddish brown awl-shaped bristles. 



"A day or two after transforming. the black eyes show through the pupal 

 envelope at the base of the snout, and in a few days more the mouth parts and 



