THE CANADIAN ENTOMOLOGIST 19 



Studied. Taken by Mr. F. W. Nunenmacher in July from the blossoms of an 

 undetermined species of plant. 



Hirsutus approaches ohlongiis Casey from Utah. It cannot be the same. 

 In the latter the apical angles are acute, pronotum finely punctate, frontal 

 impressions pronounced, legs pale rufo-ferruginous, sides of the pronotum 

 extremely feebly arcuate from base to apex. In hirsutus the epipleura are in- 

 flexed apically and it therefore agrees with ur sinus Casey. The specimens of 

 hirsutus before me constitute a very homomorphic series and vary only in 

 size. . V 



NOTES ON THE LIFE-HISTORY OF PACHYPSYLLA 

 CELTIDIS-GEMMA RILEY. 



BY HARRY B. WEISS, 



New Brunswick, N. J. 



This species, which was described by Riley in 1884 (Proc. Biol. Soc. Wash* 

 II, p. 74) is locally common in New Jersey, the nymphs forming galls on the 

 twigs of hackberry (Celtis occidentalis). These polythalamous galls are de- 

 formations of the young buds. They are variable in size and irregular in shape 

 but always bud-like or subglobular and appearing as if formed by a conglomera- 

 tion of small nodules. \'an Duzee (Cat. of Hemiptera, 1917) lists it as occurring 

 in New Jersey, New York, D.C., Ya., la.. Mo., La. and Texas. 



The galls are always formed on the new wood and in severe infestations 

 almost every bud is deformed.  Each swelling contains from 1 to many cells 

 each of which harbours a nymph. A gall 2 mm. in diameter was found to 

 consist of 1 cell; one of 5 mm. contained 7 cells; one of 8 mm. had 19 cells; one 

 of 9 mm. contained 24 cells and another of 10 mm. had 22 cells. These cells 

 are grouped so that each has a part of the outside wall of the gall covering 

 it. The cells are irregularly oval to subcircular in shape and vary considerably, 

 depending on the sizes of the nymphs occupying them. Galls containing only 

 a few nymphs appeared to have relatively larger cells. 



Overwintering takes place in the last nymphal stage, these nymphs emerg- 

 ing through somewhat irregular to regular elliptical openings in the wall of the 

 gair during the last few days of May and the first half of June. These nymphs 

 crawl on the tops of the galls and to the twigs and adults emerge shortly after- 

 ward. During the first two weeks of June at Riverton, N. J., where most of 

 the observations were made, adults were plentiful on the stems and leaves of 

 hackberry. Feeding appears to take place chiefly on the petioles of the leaves 

 and on the tender stems, the adults resting head downward. Copulation and 

 egg deposition occur shortly after emergence. Females reared in a cage de- 

 posited eggs before taking any other nourishment except that afforded by 

 the dry stems, which was apparently next to nothing. The eggs are deposited 

 on their sides on the lower leaf surface close to a vein or in the angle formed 

 by two veins. Sometimes they are found on the developing shoots or in cre\'ices 

 around the bases of leaf petioles. They are held fast to the leaf or other sur- 

 face by means of a short backward projecting stipe, arising near the basal end, 

 which is inserted in the tissue. The basal part of the leaf, where the pubescence 

 in the vein angles is thick appears to be a favoured place for eggs. Many eggs 

 are deposited singly and many in groups ranging from 2 to 8 or 10. 



January, 1921 



