4 SPRAYING CROPS 



would-be parents having died in infancy, the worms 

 of the second brood do not appear upon the scene. 



Another insect against which the spraying 

 machine is often used is the Plum Curculio. This 

 pest has been for many ^ears one of the most destruc- 

 tive enemies of the plum-grower, and is the cause of 

 the worminess and premature dropping of the fruit, 

 with which so many owners of plum trees are 

 familiar. The adult Curculio is a small, hard beetle 

 (shown magnified at c), which appears in the plum 



Plum Curculio 



a, larva; 3, pupa; c t beetle, magnified; d, plum, showing crescent mark. 

 (After Riley) 



orchard early in spring, and feeds upon the foliage 

 and flowers until the fruit is well formed. It then 

 attacks the young plums, gnawing at them to satisfy 

 its hunger, and cutting crescent-shaped marks in the 

 skin to deposit its eggs (d). In a short time these 

 eggs hatch into little grubs that feed upon the pulp of 

 the fruit, gradually working toward the pit. In a few 

 weeks they become full-grown (a), by which time 

 the infested plums have generally fallen to the 

 ground. The larvae then leave the fruit, and, enter- 

 ing the soil a short distance, change to pupae (b). 

 A little while later they again change and come forth 



