108 Agricultural Experiment Station, Ithaca, N. Y. 



coat of black paint or soot. Pear trees of all varieties and ages are 

 attacked in this State. 



Althongh the indications of the presence of some enemy is so 

 conspicuous, the depredator is so small as to be easily overlooked. 



Its Appearance. 



The immature insect- 

 forms are called nymphs 



40. — Full-grown nymph of the pear 

 psylla. ventral view, greatly en- 

 larged. 



These curious, minute, oval, immature 

 The newly-hatched ones (Fig. 43) are 

 yellow in color, with crimson e3'es, 

 and can scarcely be seen with the 

 unaided eye. During their growth 

 they gradually acquire the black 

 markings, shown in the frontispiece 

 and in figure 40, and become tinged 

 with red. A very conspicuous fea- 

 ture in the full-grown nymph is the 

 large black wing-pads on each side 

 of the body. 



The adult insect. — In this form 

 (Fig. 41) the insect strikinglj' resem- 

 bles a cicada or dog-day harvest-fly in 

 miniature. Its general color is crimson, with broad^ 

 black bands across the abdomen. Its thickened 

 femora enable it to jump like a flea. In the male 

 insect the abdomen terminates in a laree trouffh- 

 shaped segment from which ])roject ujnvard three 

 narrow copulating organs ; the end of the abdomen / 

 of the female resembles a bird's beak. 



Its Life-History. 



But little was known of the life-history of the ^^i^e^'illuit'^^'i'sS; 

 pear psylla, either in Europe or in this country, m"cii enlarged, 

 previous to the publication of our Ihilletin No. 44 in 1892. 



How it passes the winter. — The insect hibernates in the adult 

 stage, hidden in the crevices under the loosened bark on the trunk 

 and large limits of the pear trees ; a favorite hiding place on some 

 trees is in the cavity formed by the bark growing about the scar of 

 a severed limb. During warm days they often crawl about on the 



