I go 



Bulletin 396 



and 26). Wounds made later in the season do not heal so readily as do 

 those made while the fruit is expanding by rapid growth early in the 



season. Wounds made after 

 the middle of July never 

 heal with a clean scar, but 

 become covered with a 

 thick, corky layer formed 

 by the dead and dried cells 

 of the fruit. In the case 

 of these later injuries, which 

 are usually produced by 

 the tussock moth or the 

 plum curculio, the matur- 

 ing date of the variety has 

 much to do with the heal- 

 ing of the wound. Early- 

 maturing varieties do not 

 heal the wounds made after 

 ■ growth is nearly completed, 

 Fig. 26. MATURE NORTHERN SPY APPLE SHOWING THE g^^^^ [-^ many cascs brown 



IRREGULAR RUSSET SCARS THAT DEVELOP FROM RED- 

 BUG PUNCTURES SHOWN IN FIGURE 25 TOt rCSUltS. 



DEVELOPMENT OF LYGIDEA MENDAX IN RELATION TO THE GROWTH 



OF THE TREE AND THE FRUIT 



The nymphs of Lygidea mendax begin hatching just as the blossom 

 buds separate at the tips, and most of them have entered the second 

 instar by the time the blossom buds show pink and are ready for the 

 first scab spray. The nymphs are in the third instar while the trees 

 are in bloom, and most have entered the fourth stage by the time the 

 petals have fallen. It is during the fourth and fifth instars that the 

 greatest amount of damage is done, or from the time when the petals fall 

 to the time when the young apples are one-half inch in diameter. In 19 14, 

 which was a normal growing season, the adults of L. mendax were maturing 

 rapidly by June 18, and practically all were mature by June 22. The 

 adults feed on the fruits extensively for a week or more, and then, as 

 the fruits get larger and tough, they begin feeding more on the tender 

 shoots that develop. 



INJURIES CAUSED BY LYGIDEA MENDAX 



When the redbug nymphs first begin feeding on the young fruit, the 

 tissue of the core is usually punctured. In a short time, however, the 

 fruit has increased in size to such an extent that the insect's proboscis 



300 



