40 PROTECTION OF PLANTS — 1924-25 



The Adult. — Oblong-oval, convex. Brown, bronzed, strongly shining, 

 the elytral margins often greenish-bronzed; antennae and legs reddish-yellow, 

 the outer joints of former often dusky; under surface of body greenish, abdomen 

 brown, its tip paler. Head coarsely and sparsely punctate, clypeus more 

 closely punctate. Thorax nearly twice as wide as long, narrowed in front, sides 

 strongly curved, hind angles prominent; disk rather sparsely and finely punc- 

 tate. Elytra coarsely but not closely punctate, the punctures irregular on the 

 disk, a line representing the third interval smooth. Lenght 4-5 mm. 



The Egg- -The eggs of the Cranberry Rootworm measure 0.67 mm. in 

 length by 0.30 mm, in width. In shape they are regularly elongate, elliptical. 

 When first deposited, they are dirty-white in color, later becoming uniformly 

 yellow. The shell is smooth and glistening, and sufficiently transparent to 

 reveal the larval outline before hatching. 



The larva. — The full grown larva measures from 7-9 mm. Normally, it 

 lies in a curved position so that its full length is seldom revealed. Its color is 

 whitish with head light brown and thoracic shield of very pale yellowish-brown. 

 Tips of mandibles black, shading off to light brown at the base. Labrum 

 and clypeus brown. A row of brownish spines, the ambulatory setae, on each 

 ventral abdominal segment projects obliquely backward. Setae long. Legs 

 slender and small. 



The Pupa. — The pupa is slightly shorter than the extended larva, whitish 

 in color. Spines on the head and thorax are longer and stouter than those in 

 the larval stage, The middle and posterior femora are each provided with one 

 curved spine and two straight, more slender spines; two flattened hook-like 

 spines, curving outward, are found at the posterior end of the abdomen. 



Life history and habits 



According to Scammell,the appearance of the beetles is dependent upon 

 the withdrawal of the winter flood from the bog. When distrubed, they fly 

 short distances seldom more than three or four feet. The eggs are found in 

 clusters or singly ,but mostly the former, just below the surface of the soil 

 usually. The egg period varies from 6 to 11 days. The larvae feed during 

 the summer and late fall and commence to feed again in the spring soon after 

 the water recedes. The larval period lasts ten months and some larvae may 

 spend another year in the bog. The average duration of the pupal stage is 

 143^ days. 



