84 KANSAS ACADEMY OF SCIENCE. 



NOTEvS OX THE OVIPOSITION OF THE BUFFALO TREE-HOPPER. 



BY C. L. MARLATT, MANHATTAN. 



For a number of years past my attention has been drawn to the condition of the 

 limbs and twigs in an old orchard near Manhattan. The upper side of the limbs on 

 these trees have a very rough and scarred appearance, caused by thickly placed, ir- 

 regularly-circular pits, one-eighth to one-fourth of an inch in diameter, extending 

 through the bark into the sap-wood. Three years ago several hundred young trees 

 were planted in and alongside the orchard in question. The following summer 

 showed them to be covered to a greater or less extent with similar scars; and in the 

 spring of 1885 these trees had assumed such an unhealthy appearance in conse- 

 quence, that I was led to make a thorough examination of the affected limbs. 



The older limbs containing the deeper scars presented no new features, but an 

 examination of the scars in the wood of two years' growth showed them to contain 

 whitish, slightly-curved eggs ^^ of an inch long, arranged in two parallel rows, sep- 

 arated by a narrow strip of bark, each row containing from five to twelve eggs. 

 (Fig. 5, a, b.) On again opening the fresher scars in older limbs, some were found 

 to contain eggs and others empty egg-cases. 



Early in June the eggs were found to have mostly hatched, yet repeated examina- 

 tions during the early summer showed no insect on the apple trees that could be 

 attributed to the eggs, and all attempts to hatch them in a breeding-box, owing to 

 the drying of the limbs and other unfavorable conditions, were unsuccessful. 



On entering the orchard, about the first of September, large numbers of the Buf- 

 falo Tree-Hopper {Ceresa bxibalus) were observed, on my near approach, to fly from 

 me, with a loud buzzing noise, to other parts of the orchard. The presence of this 

 insect in such numbers on the limbs of the apple immediately led me to think them 

 the agents of the injury done; and after an hour's careful search, rendered doubly 

 difficult by the swaying of the trees in a strong southwest wind, and the extreme shy- 

 ness of the insect, one was seen in the act of inserting its eggs in a twig near the 

 ground. 



An examination of the work done by this tree-hopper, and similar punctures 

 which were found in considerable numbers on the young limbs, showed them to be 

 identical with the scars seen on the older limbs, the widening of the latter being 

 caused by the growth of the wood. Repeated observation of the work of this insect, 

 from September 6th to October 24th, forms the basis of the following account of its 

 oviposition. 



The female chooses by preference a twig of two or three years' growth, not, how- 

 ever, confining its work to limbs of this age. Eggs are deposited quite as readily in 

 the new growth of old as of young trees; and my observation would lead me to be- 

 lieve that certain varieties, owing to differences in the texture of the bark, are more 

 liable to be attacked than others. During oviposition, the female may head away 

 from or toward the trunk. ( Fig. 5, d, c.) A slightly curved slit through the outer 

 bark is started with the ovipositor at right angles to the body, and the cut is made 

 from the point of insertion posteriorly, the ovipositor constantly assuming a more 

 and more slanting position as the cutting proceeds, till at the close it lies almost 

 against the abdomen. At the beginning of this operation the body is raised on its 

 limbs, and sways from side to side; but as the cutting continues backward the vibra- 

 tory motion ceases somewhat, and the abdomen is lowered, till, on the completion of 

 the slit, it rests on the twig. The insertion of tlie eggs immediately follows. Begin- 

 ning at the end of the slit last made, the ovipositor is thrust down through the bark, 

 reaching the cambium layer, the abdomen of the insect resting on the limb, and in- 



