THE LESSER PEACH BORER. 



•39 



Table I. — Mcasin-rnirufx of the head of the larva of Si/iiantJicdoii pictipes in 



each of the six instars. 



After hatchino- the youn.u- larva enters the tree by the way of a 

 crevice and soon bc<>-ins to feed on the soft livino- tissues. It grows 

 rather rapidly and makes an irregular burrow between the living bark 

 and wood of the tree. This channel, in time, becomes tilled with 

 semiliquid gummy exudations and the reddish frass of the larva. 

 AVhere the larva enters there is left a small pile of fine reddish wood 

 dust. It is partial to wounds or diseased areas on the trunk, but. as 

 formerly stated, may occur anywhere on the tree, from the crown of 

 the root to the larger branches, and thus may be found feeding side by 

 side with the peach borer. 



In confinement the larva^ will feed readily and grow on fresh 

 pieces of peach bark; Mr. Quaintance has fed one for several days 

 on peach leaves. AVlien young, they are able to suspend themselves 

 with silk, and Bailey (1870) has observed them '' drinking " moisture. 



After the larva attains full growth and is ready to pupate, if some 

 distance from the edge of a wound or crack, it cuts a hole through, 

 or nearly through, the outer bark, and constructs a cocoon under this 

 in a suitable cavity, so that its anterior end is against the opening. 

 If it is near the edge of ruptured bark, which is more commonly the 

 case, the cocoon is made just within the boundary of the wounded 

 area, so that the pupa easily pushes out when ready to issue as an 

 adult. In old peach trees with cracked bark the cocoons are usually 

 found in this position. 



The cocoon is constructed of pieces of bark chewed into fine bits, 

 frass, and silk secreted by the larva, and is light yellowish brown in 

 color and soft to the touch. An old cocoon, however, is dark in color, 

 and hard and brittle. The size of the cocoon varies, but it is always 

 several millimeters longer than the pupa which it incloses. 



llic pupa. — The larva, having formed a cocoon and inclosed itself 

 within, waits several days and then pupates. The pupa (fig. 10, <7) 

 is brownish jj^ellow in color, darker at the edges of the segments, 

 sutures, head and wing covers, spindle-shaped, and is broadest at 

 the first abdominal segment. It has all the characters normal to its 

 family. The seta? are sparse and minute. The spines on the first 

 abdominal segment are very weak ; in the female there is but a single 



