warm spring days, copulate, and begin the deposition of eggs before the leaves 

 have expanded, placing them singly or in rows or bunches in creases of the 

 bark of the twigs, on old leaf scars about terminal buds, and later, after the 

 leaves begin to unfold, on the leaves themselves, as already described. The 

 egg laying goes on during April, probably later in the North than as far south 

 as Maryland. The larvae hatch in from ten to seventeen days (from ten to 

 twelve days being the ordinary summer period), station themselves on the leaf 

 petioles and in their axils on the fruit, but chiefly over the surface of the leaves. 

 The moment they begin feeding the secretion of honeydew commences, and in 

 a very short while the bulk of the liquid will be several times that of the insect, 

 rapidly increasing until it forms a good-sized drop. This, when there are mil- 

 lions to aid in the work, soon becomes abundant enough to fall as a shower 

 from the tree whenever it is shaken by the wind. Mr. Slingerland shows that 

 there are live molts, including the last change from the pupa to the adult insect, 

 and the life from the laying of the egg to the adult covers a period of about 

 thirty days, the periods between molts varying from three to seven days. 



RECORD OF BROODS FOR MARYLAND. 



The adults were very numerous July 20 in Maryland, frequently fifteen or 

 twenty resting along the midrib of a single leaf. They were depositing their 



eggs along the midrib on the upper sur- 

 face, and also thickly along the serrated 

 margin, but on no other part of the 

 leaf. From July :!I to August 3, when 

 again examined, the eggs were much 

 more numerous and had been fre- 

 quently deposited in small clusters, live 

 to eight together, along the midrib and 

 at the margin of the leaves. Scarcely 

 any of the eggs at this time had been 

 hatched, at least not more than L' to .", 

 per cent, and the adults were still al- 

 most as numerous as ever and busily 

 ovipositing. This brood, which was 

 the maximum one of the season, was 

 with little doubt the third one from the 

 hibernating individuals — a month being 

 the normal period for a generation. 

 A fourth brood of adults appeared 

 about the last of August, and a fifth 

 about the 1st of September. In breeding cages over young potted pear trees 

 no difficulty was experienced in getting the fourth and tilth broods in large 

 numbers, but in the orchard on the mature foliage — prematurely mature, from 

 the sapping of the insects— the fourth brood was very scanty in number, show- 

 wing not more than one where there were a thousand before, and this in the 

 face of the fact that more eggs had been deposited than for any previous brood. 

 The further decrease with the tilth brood was as marked, and the greatest diffi- 

 culty was experienced in finding a single adult. 



TIIF FUTURE OUTLOOK. 



Judging from the history of the pear-tree 1'svlla in the North, we may expect 

 that the injury will he very much less in future, even if there is not an entire 

 cessation of the trouble and a disappearance of the pest. The fact that this 

 insect was imported into the United States with pear trees over sixty years ago 

 and was long since widely distributed throughout, the pear districts of the 



-Pear tree Psylla: nymph— greatly 

 enlarged (original). 



