New York Agricultural Experiment Station. 315 



take in account the cost of labor involved in the operation. Much 

 of the fruit left on the trees showed one or more of the characteristic 

 scars of the insect, which detracted not a little from the general 

 appearance of the crop. 



Various references in literature indicate that the scars in pears, 

 arising from the attacks of this pest, have been confused with the 

 work of other species of insects. The injury by the cigar casebearer 

 (Coleophora fletcherellaFem.) is in some respects quite similar, but it 

 may be readily recognized by the fact that the initial wounds are 

 round, which on healing preserve their original contour. (See 

 Plate XV, fig. 2.) Other insects that frequently attack pears in 

 New York are the plum curculio (Conotrachelus nenuphar Hbst.) 

 and the green fruit-worm ( Xylina sp.), which, however, produce very 

 characteristic injuries. (See Plate XV, figs. 1 and 3.) 



The work of the false tarnished plant-bug on grape is less con- 

 spicuous than on the foregoing fruit. The injuries to the foliage 

 are quite similar to those on pears, and are most noticeable on the 

 newly-unfolded leaves. Of a more serious nature are the attacks 

 of the insects on the blossom clusters. The young nymphs pierce 

 the bases of the unopened buds and the tender fruit stems. The 

 wounds turn black, and if the feeding has been extensive the buds are 

 checked in their development, and later drop, causing imperfect 

 clusters of fruits. (See Plate XVI.) 



In our study of invitus we have not observed it at work on peaches 

 under natural conditions, but under confinement nymphs of the 

 third and succeeding instars and adults readily attacked the fruit. 

 To casual observers the first sign of the work of the older nymphs is 

 the appearance of minute black points or specks on the surface of the 

 pubescence, covering the skin of the fruit. A close examination of 

 these areas will show that they are composed of discolored gummy 

 exudations in which the hairs have become matted or glued together. 

 In removing the pubescence from the points of discharge it will be 

 found that the gum is rather strongly attached, and cannot usually be 

 removed without injuring the surface of the fruit. The gum exudes 

 from very small punctures in the epidermis of the peach, which are 

 round or very slightly elongated. The margins of the perforations 

 are hardened, but the callous areas do not extend below the skin, and 

 yet they resist scraping. The gum first exudes in the form of a small 

 globule, which is considerably larger than the puncture. The dis- 



