STATE HORTICULTURAL SOCIETY. 147 



fered with, make a complete revolution before they resume their usual 

 course. The leaves curl up, and become matted around the curl so as to 

 make a safe harbor for the lice-like larvae, which, during the summer, 

 appear on the under surface of the leaves. I presume we can get clear of 

 this insect, after the larv^ are produced, by cutting off the curls and 

 burning them." 



Although neither of these species has yet been positively detected in 

 Illinois, I have some reason to believe that the former, or some closely 

 allied species, appeared on fruit trees in the vicinity of Chicago last year. 

 I tried, but failed, to procure specimens, so was unable to decide with cer- 

 tainty. ^ 



The following species of this genus were described by Dr. Fitch, in 

 1 85 1, in a catalogue of the insects in the New York Cabinet of Natural 

 History. I give his descriptions as I find them, as I am unacquainted 

 with them. He appears to have been unacquainted with the habits of 

 the first two : 



7. Psylla tripunctata, Fitch. The Three-dotted Psylla. 



Wax yellow, with black back ; legs and antennre, pale yello'.v, the 

 latter black at the tips; the front wings, transparent (hyaline); nerves, 

 brown, widely margined with smoky yellow beyond the forks, a blackish 

 dot on the middle of the terminal margin of each of the inner apical 

 cells. Length, 0.16 of an inch. Female. 



8. Psylla quadrilineata. Fitch. The Four-lined Psylla. 



Bright fulvous or yellowish ; the front wings, hyaline : the nerves, 

 blackish; four whitish longitudinal lines on the middle of the hind thorax 

 (metathorax) : abdomen, black with a yellow band at its base. Length, 

 0.12 of an inch. Female. 



9. Psylla carpini, Fitch. The Hornbeam Psylla. 



Light green or greenish yellow ; fore wings, hyaline ; nerves, light 

 green. Length, 0.16 of an inch. Male and female. Common on the 

 Hornbeam in July. 



10. Psylla annulata, Fitch. The Annulated Psylla. 



Straw yellow; legs, white; fore wings, hyaline, with the nerves straw 

 yellow; antennae, black, except the basal portion, which is straw yellow, 

 annulated with black. Length, 0.15 of an inch. Male and female. Occurs 

 on the sugar maple. 



The same author ^nentions another species — 



11. { Psylla nrticcexolens), found on nettles, of which I have not seen the 



description. 



Walker also mentions another species — 



12. Psylla quadrisignata, of which I have not seen the description. 



