ELM LEAF BEETLE. 82 1 



The writer has not followed out this matter carefully in Con- 

 necticut, 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 important natural enemies of the elm leaf 

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

 trichum globuliferiim Speg. (S. entomophilum Peck), which 

 attacks the pupse 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 

 wet, the fungus developed and killed a great many beetles. 

 Beetles attacked by this fungus are covered with white mold, 

 as shown on Plate LV e. 



In 1907 the elm leaf beetle, though doing some damage 

 throughout the state, was much less serious than in 1906, but an 

 extreme drought prevailed, almost no rain falling during July 

 and August, and the fungus could not get in its work. Con- 

 sequently most of the beetles matured and transformed, and were 

 ready to attack the trees in 1908, doing serious damage. It was 

 also very dry in 1908, and the Sporotrichum could not prevail. 

 After a light rain late in July the writer saw a number of infested 

 pupse and adult beetles, but it was after most of them had trans- 

 formed and the beetles flown away, and the rain soon dried up, 

 making it impossible for the fungus to continue to develop. These 

 conditions indicate, therefore, that the pest will be abundant and 

 destructive next year, and all citizens should be ready to combat it. 



The writer believes that the fungus just mentioned constitutes 

 an important check on the beetle in seasons when there is much 

 moisture at the time of pupation, and this view is also shared 

 by Dr. G. P. Clinton, botanist of this station, who has observed 

 its work in this vicinity. 



In Europe there is a minute chalcidid parasite known as 

 ' Tetrastichus xanthomelcenw Rond. which attacks the eggs of 



