318 EDITORIAL [Vol. 15 



an orchardist's standpoint unsatisfactory type of poisoning may give 

 all the protection needed in wild areas and if this should prove to be the 

 case and could be clearly established, it might be entirely practicable 

 to provide for a system of artificial checks which would do much toward 

 maintaining a normal relationship between insect and plant life. The 

 aeroplane with its distribution of the dust from above affords a ready 

 means of placing the poison on parts of trees preferred by a number of 

 destructive leaf feeders. The possibilities of any such method can be 

 determined only by large scale work with a number of species and with 

 this in mind we endorse the work in New England and express the hope 

 that it is only the beginning of a serious attempt to determine possibili- 

 ties along these lines. 



The apple red bug {Heterocordylus malinus Reut.) whose distribution has been 

 generally known as the northeastern states is quite common in various parts of 

 Iowa and has been reared from Crataegus and apple at Ames this year. There are 

 specimens in the Iowa State College collection taken at Ames as early as 1897, 

 twelve years before the species was described by Reuter from New York. The 

 writer's observations in Iowa as well as in New York indicate that Crataegus is the 

 preferred host and probably the original food plant of this species. 



Walter H. Wellhouse 



Infective Beet Leafhoppers {Eiitettix tenella Baker) do not Transmit Curly Leaf 

 Daily. — An infective beet leafhopper which completed all of the nymphal instars on 

 a blighted beet does not transmit curly leaf daily. Three infective males, bred from 

 eggs deposited by infective adults, passed through the last moult on July 30, 1919 

 and were confined in three cages. In the first cage a male was provided with a 

 healthy beet daily; in the next experiment a healthy beet was put in the cage with 

 the hopper at the end of every second day, and in the last experiment another male 

 was allowed to feed, alternating daily, on a curly leaf and healthy beet. The work 

 was conducted out-of-doors at Manteca situated in the northern part of the San 

 Joaquin Valley. Five sugar beets developed curly leaf of 49 beets used in the ex- 

 periment. 



In the next experiment 1, 2, 3, 4 and 5 infective males which completed all of the 

 nymphal stages on a blighted beet were confined in five cages in the greenhouse at 

 Berkeley. A healthy beet was placed in each cage daily. When a leafhopper 

 died, another was put into the cage, except in the one containing a single specimen. 

 The experiment extended over a period of 54 days from November 1-December 24, 

 1920 and was discontinued when the single male died. The results follow: 



One infective male transmitted curly leaf to 3 beets ( 5.5%) in 54 days. 

 Two infective males transmitted curly leaf to 10 beets (18.5%) in 54 days. 

 Three infective males transmitted curly leaf to 31 beets (57.4%) in 54 days. 

 Four infective males transmitted curly leaf to 28 beets (51.8%) in 54 days. 

 Five infective males transmitted curly leaf to 34 beets (62.9%) in 54 days. 

 Mean maximum 78.9 F., mean minimum 61.7 F., mean 70.3 F. temperatures. 



Henry H. P. Severin, Ph.D 

 Calif. Agr. Exp. Sta. 



