PROCEEDINGS, 1916. 39 



OVIPOSITION. 



The eggs, are deposited in two or three year old wood of the apple and pear, but 

 the characteristic scars have also been noticed on maple, poplar and other trees. Young 

 trees suffer most and the damage to them is most noticeable, but the young growth of 

 old trees is freely attacked. As shown in the figure the eggs are laid in two parallel or 

 slightly curved rows. The oviposition of the insect has been well described by Marlatt* 

 as follows: 



"Facing either toward or away from the trunk, the female makes with its oviposito- 

 a slightly curved slit through the outer bark, cutting in a direction posterior to the in- 

 sect, so that the ovipositor, which Is at first extended nearly at right angles to the body, 

 at the competion of the slit, lies almost against the abdomen. The eggs are inserted 

 very obliquely through the bark and nearly at right angles to the twig, immediately 

 after the completion of the preliminary incision, beginning at the end of the slit last 

 made, and are thrust well down into the cambium layer between the bark and the wood. 

 A period of from one-half to two minutes is required for the insertion of each egg, after 

 which the ovipositor is partly withdrawn, moved a little forward, and re-inserted, a- 

 bout twenty minutes being required for the cutting of the slit and filling it with eggs, 

 which, in each slit vary in numbers from 6 to 12. As soon as the first slit is completed a 

 second one is made parallel to and slightly curving toward the first, without change of 

 position by the insect. The ovipositor, however, is thrust in at a very considerable angle 

 from that assumed in the first case, so that it crosses beneath the bark the cut first 

 made, and the narrow intervening bark between the two incisions is cut entirely loose. 

 After completing the two complementary slits and filling them with eggs, the female 

 rests a considerable time before again beginning operations. The number of eggs de- 

 posited by a single female exceed? 100, and possibly 200. Rather late in the fall, a fe- 

 male which had just finished a pair of slits which contained some 20 eggs, was found to 

 still contain 40 eggs in her ovaries." 



The death of the bark and the partial stoppage of the growth between the two 

 rows of eggs has the effect of preventing the eggs from being crushed or forced to the 

 surface by the rapid growth of the twig. In some cases this actually occurs. 



For purposes of oviposition the females appear to prefer the south side of the tree 

 and the upper part of the limbs. They also show a preference for the two or three year 

 old wood. 



NATURAL ENEMIES 



A large proportion of the eggs of the buffalo tree-hopper are destroyed by minute 

 egg parasites. Two hymenopterou^ parasites have been recorded as attacking the eggs 

 of this species, viz.: Trichagramma cerasarum Ashm and Polynema striaticorne Gir. 



In addition to these parasites, large numbers of the nymphs both of this species and 

 of Ceresa taurina are carried off by spiders of various species, while engaged in feeding 

 on the herbage bene th the tree. 



ACK NOWLEDGEMENTS. 



The daily observations and records in connection with the foregoing studies were 

 made by Mr. H. G. Payne, in the laboratory at Kentville. Mr. C. B. Gooderham also 

 gave valuable assistance at various times. 



♦Insect Life, Vol. VII: 8-14 (1894) 



