New York Agricultural Experiment Station. 313 



found on the tender leaves of natural apples which have been inter- 

 twined with the wild grape. Dr. Forbes 9 notes a destructive 

 attack by invitus on the young leaves of the common soft maple 

 {Acer saccharinutn L.) which caused them to curl and to become 

 specked with numerous semi-transparent spots. 



Dr. Howard 10 records also an injurious outbreak by this species 

 on peaches in which the insect sucked the juices from the young 

 fruits, causing them to shrivel. Similar injuries to peaches have 

 been described by Lowe 11 which he attributed to Lygus pratensis. 

 He observed, early in June, many of the insects upon young peaches, 

 which they repeatedly punctured with their sharp bills. Drops of 

 sap formed about the wounds, while the skin began to wither. The 

 injured peaches, when mature, were deformed to a greater or less 

 degree, depending upon the extent of the earlier injuries. From his 

 account it is evident that he assumed that pratensis was responsible 

 for the injuries; but owing to the great similarity of the two species 

 there is a possibility that he failed to recognize invitus, a mistake 

 that could easily occur. Unfortunately he made no collections of 

 the insects, which would have settled any doubt as to their identity. 

 His determination of the species is called into question as, thus far, 

 by inspection of orchards where there have been abundance of nymphs 

 and adults on surrounding weeds, we have not observed pratensis 

 attacking peaches. By confining the adults in cages built about 

 individual peaches the insects will, however, attack the fruit in a 

 manner similar to that described above. 



Besides the foregoing fruits, nymphs of invitus are of common 

 occurrence on the young leaves of the sumach (Rhus canadensis 

 Marsh). 



NATURE OF INJURIES. _ 



In its attacks on pears, invitus apparently shows a preference at 

 first for the tender leaves, attacking those that are unrolled along the 

 margins of the fold or those that are expanding at the apices or along 

 the edges of the unfolded margins. (See Plate XI, fig. 1.) The 

 tissues about the points of injury turn black, and if the punctures are 

 numerous, more or less extensive areas along the margins of a leaf 

 shrivel and become dry. The dead portions later become detached 



"Rpt. St. Ent. 111. 3:110-111. 1SS4 (1S85). 



10 U. S. Dept. Agr. Bu. Ent. Bul. n. s. 30:98. 1901. 



"N. Y. Expt. Sta. Bui. 180:135. 1900. 



