120 PROTECTION OF PLANTS, 1P16-17 



coloured hairs, diameter 1.1mm. (1/24 inch.) The clypeus is often 

 darker coloured. Parallel to the epicranial suture are two thin light 

 coloured lines which meet at the base of the head. The prothoracic 

 shield is concolorous with the head and is marked with a light coloured 

 longitudinal median line. The mesothorax, metathorax and abdominal 

 segments are cinnamon brown and are somewhat wrinkled. The anal 

 shield is usually brown, but lighter in colour than the head and pronotum. 

 The setae are light coloured and are borne on very slightly raised tubercles 

 which are darker than the body. The three thoracic legs are black. The 

 prolegs are borne by the fourth, fifth, sixth, seventh and tenth abdominal 

 segments. 



Ptipa. — The pupa is about 6 mm. i\ inch) long, light yellow when 

 first formed, turning to a light brown. It bears a number of scattered 

 delicate light coloured setae. On the ventral side the sheaths of the appen- 

 dages extend as far as the posterior edge of the fourth abdominal segment. 

 The first six abdominal segments are free. The seventh to tenth are closely 

 united to form a compound terminal segment. The first segment is bare, 

 the second to sixth bear on both anterior and posterior margins of the 

 dorsum a transverse row of numerous very short black spines or tubercles, 

 directed backwards. On the terminal segments there are five such rows, 

 the spines increasing in size towards the anal end. The cremaster consists 

 of a circlet of hooked hairs. 



Injury — Nature and Extent. 



There is only one brood each year, but the larvae live throughout a 

 portion of two seasons and the injury done by the young larvae in the 

 summer and fall differs from that done by the older larvae in the following 

 spring. 



Spring Injury. — During the spring the caterpillars injure the leaf buds, 

 flower buds, leaves, setting fruit and sometimes the young twigs. As soon 

 as the buds begin to swell and the outer leaves of the fruit buds to show 

 green they are attacked by the caterpillars which begin to emerge at 

 this time from their hibernacula. They tunnel into the opening buds either 

 frorh the top or from the sides. Evidence of their presence in the bud 

 is shown in the brown excrement at the entrance to the tunnel. Within 

 the bud the caterpillar feeds on the developing flowers, destroying all or 

 most of the flowers in a cluster. In one orchard, in which the infestation 

 was comparatively light, eighteen per cent of the flowers were destroyed. 

 In badly infested orchards the percentage of flowers injured is considerably 



