328 FoRTT-siXTE Report on the State Museum 



The mature insects made their appearance about June 15th, and com- 

 menced to feed soon after emerging. " They appear to secrete no 

 honey-dew." Within a week copulation ensued, and oviposition soon 

 began. There were at least four broods during the year, at intervals 

 of about a month. The adults of the summer broods were the most 

 numerous July 2()th, August 20th, and September 25th — the last 

 constituting the hibernating form. 



This last-named form varied so much from the preceding summer 

 broods, being one-third larger and of much darker colors, that they 

 were believed, at first, to be a different species. On careful comparison 

 with descriptions of Psylla simulans Foerster, of Europe, it was found 

 to present so close a resemblance as to leave scarcely a doubt that P. 

 simulcms had been described from the winter form of P. pyricola, and 

 that the species is dimorphic, appearing in two distinct forms during 

 the year, as some others of the Psyllid;v are known to do. 



The P. simulans form continues to feed until the leaves fall, when it 

 retires to its hiding places for the winter. None were observed in 

 copulation during the autumn. 



For descriptions of the insect in the several stages, the paper of Mr. 

 Slingerland may be consulted. 



Eggs of the Psylla. — Among the few notes made by me during the 

 prevalence of the insect in 1891, the following occurs: 



Prof. C. H. Peck, brought from his garden at Menands, N. Y,, on 

 June 15th, leaves of a pear tree having numerous eggs of the Psylla 

 on both the upper and lower sides, but rather more abundant on the 

 lower side. Many are placed along the midrib from the base to the 

 tip, and some on other parts of the leaf, usually beside a vein and thrust 

 in almost out of sight between the twisted hairs clothing the surface. 

 The hair-like thread projecting from the narrow end of the Q^^, is, in 

 most, a little longer than the Q^^^^ but in some, twice 

 the length. The q^^ is not attached by it to the leaf 

 but by a transparent teat-like process given off from 

 Fig. 14.— Egg of the pear xvQd^x the broader end, as shown in the accompanying 



tree Psylla. .. q- i 



ngure. Ihree eggs were seen standing close 

 together on a leaf with the thread pointing upward, as if it were the 

 remains of the secretion in which the eggs Avere enveloped at their 

 oviposition. 



Nearly all of the eggs are near their hatching as the inclosed larvae 

 are seen within, separated from the shell. On one leaf there were about 

 thirty eggs. Young larva% apparently disclosed Avithin a day or two, 

 were also present. Cast pupa-cases were attached to various portions 

 of the leaves. Professor Peck noticed the adults mating when the 

 leaves were gathered. 



