Eleventh Report op the State Entomologist 163 



of which the catkins were examined, each and every one showed many 

 of the seed-galls. Of some of these, more than one-half of the seeds 

 were infested, and a number of galls were observed to contain two larvae. 

 On October 9th they were apparently mature and ready for pupation, the 

 window-like spot for the escape of the insect being visible. The presence 

 of the insect is easily recognized by the transformation of the normal 

 alate seed into a globose ball, displaying on its side a round spot where 

 the shell has inwardly been eaten to a thin pellicle to admit of the escape 

 of the contained insect. (PI. I, fig. i, a, b, c.) 



The insect was also found in catkins examined in other parts of 

 Albany ; quite abundantly on a small birch on the grounds of Grace 

 Protestant Episcopal church; and at West Albany, near the railroad 

 station. 



Identification of the Insect, 



From catkins collected May 3d in Washington Park, a number of the 

 imagoes were obtained the same day and on a few following days 

 examples of which were submitted to Baron Osten Sacken, who pro- 

 nounced them identical with the European Cecidoitiyia betuloe Winnertz. 

 At this time it was found that many of the galls had already disclosed 

 their occupants. Some infested catkins which had been collected by me 

 during the month of October, 1886, failed to give any of the producing 

 insects, probably from having been deprived of moisture during the 

 winter and spring, as Mr. Inchbald had stated in a letter to me, that 

 they require moisture for their development and need to be sprinkled 

 with water occasionally. 



Development of the Larvae. 



Catkins collected September 11, 1896, in Washington Park, were found 

 to be quite abundantly galled. At this time the larvae varied from the 

 full grown ones in white cocoons and with distinctly windowed galls, to 

 small individuals not one-sixth their size ; most of them were full grown 

 though not with distinct windows. On the i8th inst. it was found that all 

 the larvae were full grown, each with a distinctly windowed gall; they had 

 shrunken a little and become more rotund and the surface of the skin was 

 finely corrugated. Each was surrounded with a white cocoon, and it is 

 evident that they pass the winter in this condition. 



According to Theobald, the larvae of this species pass the winter in the 

 seed-capsules of the birch, Betida alba. They pupate in the same place, 

 sometimes two lying side by side in the same capsule. The perfect in- 

 sect appears the latter part of March and during April. 



