SOME 8CALE INSECTS. 97 



DiSOUSSIOjS". 



Mr. Howard illustrated his lecture with stereopticon slides and 

 with specimens of all of the insects considered. 



Professor Benjamin M. Watson asked, How can scale insects 

 on small trees best be killed ? 



Mr. Howard replied that in California fumigation with hydro- 

 cyanic gas, under an oiled tent, is most extensively practised. 

 In the East this treatment has not been so successful. Here we 

 must rely mainly upon spraying. 



J. W. Manning stated that in good orchards in California the 

 insects are properly treated, but in other places they are as 

 abundant as they are in neglected orchards in the East. He him- 

 self had seen orchards in which the Vedalia was not abundant 

 enough to keep down the fluted scale. 



William C. Strong moved a vote of thanks to Mr. Howard for 

 his able and comprehensive lecture, Avhich was unanimously 

 passed. 



Nathaniel T. Kidder inquired what kind of weather is most 

 desirable for applying remedies. 



Mr. Howard replied that it was all important to apply them 

 in dry weather. Some of our best washes, notably the whale-oil 

 soaps, act slowly and do not reach their full effect for several 

 weeks. If there is one season of the year which more than 

 another is apt to be dry for an extended period, that season 

 should be chosen for the application of these washes. The long- 

 dry spell in the early winter in California is one reason for the 

 superior action there of the lime, salt, and sulphur wash and the 

 resin wash. 



Hon. William E. Sessions inquired about the method of spread 

 of the San Jose scale. 



Mr. Howard stated that its natural spread was extremely slow, 

 the young crawling but a short distance, while at forty-eight 

 hours of age they cannot move. The spread, then, is largely ac- 

 cidental. The active young cling to the feet of bird^ and to fly- 

 ing insects and are thus carried from tree to tree and from 

 orchard to orchard. The largest spread is accomplished by the 

 commercial transportation of the insect on nursery stock and 

 fruit. A young tree which has been badly infested for two or 

 three years is likely to die. Very badly infested trees should be. 

 dug up and burned. 



