101 



eleven days, but iu the field the uymphs did uot emerge until about May 

 10, when the leaves had begun to unfold. The minute creatures im- 

 mediately crawled as far as possible into the leaf axils and began suck- 

 ing the sap. This seems to ])e the favorite point of attack through the 

 season, and nymphs are in\ ariably found in the leaf axils or on the 

 stems of the fruit, unless very numerous, when they cluster about the 

 branches just below the leaves or along the midrib of the leaves. They 

 prefer the younger and tenderer branches and leaves, which often droop 

 early in the season from the excessive loss of sap occasioned. 



By carefnl observations upon isolated individuals, I have found that 

 the nymphs moult five times, including the one at which the adult 

 insect ai)pears. 



Adults of the first spring brood began to appear about June 1. For 

 two days after emerging they were of a greenish color and then took 

 on the characteristic red and black markings. Eggs from these adults 

 were plentiful about June 15 and were foand on the under side of the 

 younger leaves, usually partially hidden in the i)iibesceuce along each 

 side the midrib. Adults of this second brood appeared in about thirty 

 days, or July 15. There will thus be at least three and probably four 

 broods during the season. During the summer all stages of the insect 

 maybe found on the trees, owing to the overlapping of the broods. 



The summer forms of the adults are smaller and less intense in color- 

 ing than the hibernating adults. In the former the front wings are of 

 a yellowish tinge, and the veins, even in dark specimens, are light yel- 

 low, while the front wings of the latter are nearly transparent, with 

 dark shades in the cells and very dark l)rown or black veins. After a 

 careful comparison of both forms with the descriptions of the four known 

 pear Psyllas, pyri, pyricola^ pyrisuga^ and simulans^ I am led to believe 

 that the insect in question is Psylla pyricola, and that Fyslla simulans 

 is the winter variety or hibernating form of pyricola. 



Last year the nymphs were so numerous by June 15 that the honey- 

 dew secreted covered the branches and trunks of the trees, and was 

 accompanied by the usual black fungus, which gave the trees a very 

 smoky, unhealthy appearance. The honeydew appears to be secreted 

 only by the nymi^hs, but in what manner I do not know. The excre- 

 ment and honeydew are distinct, the former having a firm, whitish 

 appearance, while the latter is clear, like water. I think both secre- 

 tions come from the anus. 



REMEDIES. 



I have fought this pest in all its stages except the adult. , It is claimed 

 by those who tried spraying the adults in the summer that they were 

 exceedingly active and arose from the tree in a cloud as soon as the 

 spray struck the leaves ; possibly some were killed upon returning to 

 the tree by the adliering spray. The hibernating forms, however, are 

 quite inactive, sometimes coming from their hiding places and crawling 





