4 BULLETIN 263, U. S. DEPARTMENT OF AGRICULTURE. 



stage. The middle and posterior femora are each provided with one curved spine 

 and two straight, more slender spines; two flattened hooklike spines, curving outward, 

 are found at the posterior end of the abdomen. 



LIFE HISTORY AND HABITS. 



ADULT STAGE. 



Emergence of the beetles from the soil begins about mid-June, the 

 maximum number emerging in breeding cages June 28. This date 

 will vary, however, depending upon the time of drawing the winter 

 flood from the bog; as early as June 6 beetles in the process of harden^ 

 ing were taken from the soil whereas the latest capture of the season 

 was made October 20. They are easily captured by sweeping the 

 bog with a net and with more difficulty by searching in the fallen 

 leaves and refuse which often form a layer of trash an inch or more 

 in depth under the vines. The beetles go into the trash so that they 

 may deposit their eggs in the soil, and to find them one must carefully 

 turn over the Utter. Some are on the vines, feeding usually on the 

 new growth of foliage, which they attack from the outer margin. 

 Others may be found on the small berries, gouging shallow furrows 

 around the fruit. When disturbed they fly short distances, seldom 

 more than three or four feet. A few cage experiments showed that 

 the females are longer lived than the males, one female remaining 

 alive 56 days. 



EGG STAGE. 



Eggs have been found in a cranberry bog lying in a mass just be- 

 neath the surface of the ground. In rearing cages they are most fre- 

 quently deposited in masses but occasionally are found singly. The 

 highest number found in one mass and known to have been laid by 

 one female was 53 eggs. The average number of eggs per mass was 

 14. Caged beetles sometimes oviposited on the sides of the cage or 

 on fallen leaves, but most frequently the eggs were inserted about an 

 eighth of an inch in the soil. In a previous report on the cranberry 

 rootworm the writer (1914) gave the length of the egg stage as 11 

 days. Further data show that this period varies from 6 to 11 days, 

 averaging 8 days. 



LARVAL STAGE. 



The small larvae find their food in the first inch or two inches of 

 roots and soil and, owing to the fact that the fibrous roots are so 

 abundant, it is presumed that the larvae travel little in search of food. 

 Larvae may be found feeding at all times during the summer and until 

 quite late in the fall, at which time some of them go deeper into the 

 ground. November 17, Mr. H. K. Plank, of the Bureau of Entomology, 

 found larvae in a peat soil at depths ranging from an inch to 1 foot. 

 December 1 the larvae were found in the first 2 inches of a rather dry, 

 sandy soil. When feeding ceases a round cell is formed in the soil 

 within which the larva hibernates until spring. If the bog is flooded 

 during the whiter the larvae remain dormant, at least until the winter 



