121 



The exogenetic species are of course all multivorous also, aud, as re- 

 gards the insects themselves, the latter division, between univorous 

 and midtitoroKS, is the only real one; but Avhen Ave are studying the 

 fauna" of special plants both distinctions have to be considered. 



The operations of man are continually tending to cliange univorous 

 species into more or less nudtivorous ones and to multiply the number 

 of exogenetic species in plant fauna'. The various destructive Coccidai, 

 for example, Icerya 2)in-chasi, afford excellent instances of this and show 

 us how we sliould constantly be on our guard against species which, 

 undisturbed and in their native country, appear harmless. 



It is remarkable, too, how rapidly some plants, when brought to new 

 countries, will acquire a new exogenetic fauna. Thus, a few days ago 

 I noticed a cultivated Chrysauthenuim in Kingston badly attacked by 

 Lecanimn {Betnutrdia) hemisphcericum and Orthczia insignis; and an 

 olive tree in the back yard of the museum is very severely attacked by 

 Aspidiotun pcrsonafus, witli .1. ficus and A. ariicidatus in lesser num- 

 bers. 



Finally, I would venture to urge that copious records of plant faunse 

 should be made on a careful plan. It is not sufficient to merely record 

 the occurrence of an insect on some plant. We should be supplied with 

 details as to locality, abundance, presence of other insects, parts of the 

 plant infested, etc. Such details, indeed, would increase the length of 

 the records considerably, but I believe that a few full statements are of 

 more value than a large number of mere lists of names, for this reason, 

 that the latter have sooner or later to be gone over again and the ob- 

 servations repeated in order to obtain necessary particulars. 



I had intended to append a number of my notes on the plant faunje 

 of Jamaica, but this paj^er has already become too long, so I am sure 

 you will be glad that I should refrain from doing so. 



SPRAYING WITH ARSENITES VS. BEES. 



liy F. M. Webster, Woosier, Ohio. 



Although much has been said with regard to the effect upon bees of 

 spraying fruit trees with arsenites while in bloom, there seem to have been 

 no careful experiments made for the purpose of securing exact proof, 

 and therefore all assertions were necessarily very largely opinionative. 

 Bee-keepers were, as a rnle, of the opinion that bees would be killed by 

 spraying the bloom, some because their bees had died, others because 

 some one else said such results would follow. Most entomologists did 

 not care to express an opinion based on the very little accurate infor- 

 mation on hand, while others, including the writer, doubted the fatality 

 of the measure, because it was thought that the poison thus applied 

 would either blast the bloom, and thus render it distasteful, or the poi- 

 son would not reach the nectar, and, being insoluble, otherwise would 

 not affect the bees. In order to fully test the matter, the following 



