62 



MASS. EXPERIMENT STATION BULLETIN 353 



Dichelonyx spp. 



Although this group of beetles is not considered to be important, they often 

 appear in numbers on the foliage of various broad-leaved deciduous trees and 

 some occur on needle-bearing evergreens, usually in the first half of the growing 

 season. 



Dichelonyx elongata Fab. is a common species with feeding habits and injury 

 to foliage similar to those of the rose chafer, Macrodactylus subspinosus Fab., and 

 has been reported on numerous species of hardwoods. Other species are D. 

 elongata Schonh., on birch and alder; D. albicollis Burm., mostly on pine; D. 

 diluta Fall., and D.fuscula Lee, mostly on oak; and D. subvittata Lee, on hazel- 

 nut and oak. 



Description. The beetles vary from about ^4 

 to }/2 inch in length and are oblong in shape with 

 straight sides. The general color varies from a 

 dull brownish-yellow to a dark brown but the 

 wing covers usually exhibit a greenish or bronze 

 luster. The legs are mostly brown and fairly long. 

 The mature grubs resemble those of June beetles 

 but are smaller and differ in many characters which 

 can be distinguished only by microscopic exam- 

 ination. 



If control measures should be necessary, a spray 

 consisting of 4 pounds of lead arsenate in 100 

 gallons of water with 2 pounds of flour or 1 pound 

 of calcium caseinate as a sticking agent should give protection. 



A Dichelonyx Beetle. 

 Enlarged. 



Blatchley, W. S. Coleoptera or Beetles (Exclusive of the Rhynchophora) known to occur in 



Indiana, pp. 951-953. 1910. 

 Britton, W. E. Conn. State Ent. Rpt. 28:680. 1929. 

 Britten, W. E. Conn. State Ent. Rpt. 31 :505. 1932. 

 Doane, R. W., Van Dyke, E. C, Chamberlin, W. J., and Burke, H. E. Forest Insects. pp. 



233-234. 1936. 

 Felt, E. P. N. Y. State Mus. Mem. 8(2):694, 703,716,723. 1906. 

 Gibson, A. Can. Dept. Agr. Bui. 99, N. S.: 36. 1934. 

 Packard, A. S. Fifth Rpt. Ent. Comm. pp. 328,511,599, 636, 801. 1890. 



Imported Willow Leaf Beetle 



Plagiodera versicolor a Laich. 



This insect is a European species. It was found in northeastern United States 

 about 1915 and was probably introduced a few years earlier. It is becoming an 

 important pest of willows and poplars. The grubs skeletonize the under side of 

 the leaves and the adults riddle the foliage. 



Description. The beetles are metallic blue to blue green. They are a little 

 over 1/8 inch long and broadly oval, somewhat resembling flea beetles. 



The eggs are lemon-yellow; smooth; narrowly oval in outline, with broadly 

 rounded extremities; almost 1/25 inch long, and about 1/50 inch broad. They are 

 laid, inclined at an angle of 30 degrees, on the under side of the leaves in masses 

 of 12 to 30, the average being about 19. 



The larvae, or grubs, are brownish-black in color, slug-like in appearance, and 

 about li inch long. Glands along their sides give off a peculiar odor. 



The pupae are about 3/8 inch long and yellowish-brown in color with dark 

 spots and markings. Usually they are attached to the under side of the leaves. 



