1916 ENTOMOLOGICAL SOCIETY. 73 



turns black. Stinging of the young pears does not often result in dropping, as 

 in the case of apples. The effect of the punctures on the fruit is. however, very 

 conspicuous, it being covered with hard, granular, corky scars, which are often 

 split open as in the case of those on tlie apple. Hard, flinty areas extend into the 

 pulp, making the fruit useless for any purpose whatever. 



3. I'XJURY TO Plum. — Injury to the fruit of plums is not uncommon, where 

 these trees border on affected apples or pears, riums injured by the bugs do not 

 usually become scarred and twisted, as in the case of apples and pears, though 

 they may sometimes grow somewhat one-sided. The seat of the injury is usually 

 at the extremity of the fruit furtliest from the stem. As usual in the case of stone 

 fruits this injury is marked by the exudation of colorless gum which flows through 

 the small puncture, sometimes forming a globule and sonxotimos a coil of gum 

 which finally hardens in .the air. 



Feeding Experiments. 



In affected orchards large numbers of nymphs are frequently shaken to the 

 ground by sprays, heavy rains, winds, etc., and in numerous instances these were 

 observed feeding upon dandelions, couch grass, red clover, and other plants at the 

 base of the tree. Even when forced to feed on these plants early in the nymphal 

 life the insects seemed to be able to complete their transformations, but once they 

 had obtained their wings, they invariably sought the fruit of the apple or pear. 



A number of nymphs in their second or third instars were divided into lots 

 of ten and confined upon a number of i)Iants under cheesecloth bags. The fol- 

 lowing al)servations were made : — 



Grape {Vitis sp.). — ^The nymphs feed readily upon grape, puncturing leaves 

 and blossom clusters. The tissue surrounding the punctures turns black. 



Elm (Uli)vus americana). — The injury to the foliage of the elm was quite 

 noticeable in dark colored spots, but there was no apparent puncturing of the 

 twigs. 



Maple (Acer saccharum). — The injury to maple leaves was slight. The in- 

 jury was characterized by small translucent spots. 



Sweet Cherry (Pninus aviunh) .— Slight puncturing of leaves and blossoms, 

 but little apparent injury. 



Peach (Prunus persica). — The leaves showed visible punctures and were 

 slightly curled. Small globules of transparent gum showed where the fruit had 

 been punctured. 



Red Clover (Trifoliiuii re.pens). — Transparent areas on the leaf accompanied 

 by a gradual fading and wilting of the plant, characterized the injury to red 

 clover. 



Strawberry {Fragaria cliiJotnsis). — Strawberries showed evidence of more 

 serious injury than any of the plants experimented with. Blossoms and leaves 

 were so badly punctured that they finally withered and died. 



Couch Grass {Agropyron repens). — The blades of couch grass were punc- 

 tured quite severely, fading in color and showing other evidence of wilting. 



Susceptibility of A^arieties. ' 



Extensive observations regarding the susceptibility of varieties reveals the fact 



that of all varieties of apples the Nonpareil is by far the most liable to attack. 



In many orchards it is onlv the trees of this variety that appear to suffer at all. 



Cases have been observed in which badly attacked Nonpareil trees were surrounded 



6 E.s. 



