THE TERRAPIN SCALE. 



65 



The eggs, which are a salmon color, are deposited singly upon 

 the twigs, a favorite place being upon the ringlike scars that mark 

 the limit of the seasonal growth. (Fig. 18, d, e.) The eggs are too 

 small to be seen readily by the unaided eye. They commence to 

 hatch about the middle of May and the young seek the mature 

 scales and enter their brood chambers by way of the anal cleft. 

 When once within the brood chambers they prey upon the newborn 

 young. The ladybird larvae make their first molt within this brood 

 chamber and continue to feed until the end of the second instar; 

 by this time the Hyperaspis larvae are so large that they crowd the 

 brood chamber and often displace their host. 

 Finally the larvae leave the host and make 

 the second molt, usually at the base of a 

 fruit spur, and then attack other scales, 

 which they do by forcing their heads un- 

 der the margin and displacing them. In 

 this manner they continue through the 

 third and fourth instars, each larva de- 

 stroying many gravid scales. When all 

 the gravid females are destroyed the Hy- 

 peraspis larvae, which are then mostly in 

 the fourth instar (fig. 19), migrate to the 

 leaves and continue their feeding upon 

 such of the larvae as have reached the 

 leaves. Afterwards the ladybird passes the 

 pupal stage in a pupa case attached to 

 the leaves or to the twigs, and sometimes 

 in cavities under the bark. Most of the hibernating beetles die 

 before the first brood emerges from the pupa. 



Fig. 19.— The fourth-instar larva of 

 Hyperaspis binotata as it appears 

 when attacking the larvae of the 

 terrapin scale. Much enlarged. 

 (Original.) 



PARASITES. 



The terrapin scale is heavily parasitized, and this parasitism is 

 mostly confined to the female, though the male is slightly attacked. 

 The first and second instars are very free from parasites, but a heavy 

 attack starts soon after the young females have attached to the 

 twigs. This attack increases in violence until checked by the 

 approach of winter. Most of the parasites pass the winter within 

 the host and emerge early in the season to make a new attack, which 

 reaches its maximum just before the scales begin producing young. 



Coccophagus lecanii Fitch was the most abundant species reared 

 in 1912, but C. cognatus Howard was also abundant, especially in 

 the fall. In 1913 C. lecanii Fitch was rare. In its place C. cognatus 

 20782°— Bull. 351—16 5 



