THE ELM LEAF BEETLE. 9 



known as the Camperdown elm are favorites of the beetle. The 

 writer has seen these trees entirely defoliated in New Haven 

 when the common white, or American elms, were uninjured. 

 The American elm is, however, the next choice, followed by the 

 Scotch elm (L''. montana), and though no variety is wholly 

 exempt from attack, the winged elm (U. alata), the slippery 

 elm {U. fulva), the cork elm {U. suberosa) and the rock elm 

 ([/. racemosa) are much less frequently attacked. 



NUMBER OF GENERATIONS. 



According to Burgess,* "in New Jersey, Professor J. E. 

 Smith has recorded only a single brood and sometimes a partial 

 second brood, while in the latitude of Washington, D. C, 

 according to the observations of Messrs. Riley, Howard and 

 Marlatt, of the Division of Entomology, two annual broods and 

 sometimes a partial third brood have been found." 



Dr. E. P. Felt, -State entomologist, of Albany, N. Y., findsf 

 two well marked broods and a partial third brood at Albany 

 and Troy, N. Y. 



The writer has not followed out this matter carefully in 

 Connecticut, but all stages are found on the trees during the 

 first half of September, so presumably there are at least two 

 broods, but the egg-laying period of the adults is so prolonged 

 that the lines of demarcation are nearly obliterated. In Con- 

 necticut the leaves of the trees severely attacked by the first 

 brood generally turn brown and drop about the middle of July, 

 when the larvae are descending the trees to pupate. 



NATURAL ENEMIES. 



One of the most iinportant natural enemies of the elm leaf 

 beetle in Connecticut is a fungus known to botanists as Sporo- 

 trichum globuliferum Speg. {S. entomophilum Peck), which 

 attacks the pupae and adults in late summer, especially in a 

 moist season. In 1902 this fungus was prevalent, and the fol- 

 lowing season the elm leaf beetle did little damage to the trees. 

 In 1906 the beetles were abundant, but as the month of July was 



* Bulletin No. 4, page 17, Ohio Dept. of Agriculture, Div. of Nursery 

 arid Orchard Inspection. 1905. 

 t BuUethi No. 57, N. Y. State Museum, p.' 14, 1902. 



