326 STATE BOARD OF AGRICULTURE. 



INSECTS AFFECTING THE PEACH TREE. 

 AFIf-ECTIXG THE BOOTS. 



The Peach Borer. (Sanninoidea exitiosa.) 



By far the worst enemy of the peach, in Michigan, is the peach borer. This 

 insect is said to work also in cherry, plum, prune, nectarine, apricot, flowering 

 almond, and azalia. The adult is a small moth having partially clear wings and 

 ornamented with metallic blue and orange scales. According to Professor 

 Slingerland, the eggs are laid between June 15th and October 1st on the bark. 

 The larvae or borers, that do the injury, are soft bodied, and for the most part 

 white in color. The head and legs are brown. They work at first in the bark. 



Fig. 48. — The Peach Borer, from Riley, First Rep State Entomologist of Mo. 



and later between the bark and wood near the crown, usually a few inches 

 beneath the level of the soil. In old trees, they may work on the trunk and even 

 in the large branches. Their presence usually is made known by a copious exuda- 

 tion of gum. The winter is passed in the larval condition; some times the 

 larvae or "worms" being nearly full grown, and they range from that down to 

 a very small size. In the spring, they resume feeding, attain their growth, and 

 spin cocoons near the tunnel or burrow. The cocoon is made of silk with frass 

 and excrement woven in on the outside. About the middle of June, the adults 

 commence to emerge from these cocoons, and soon the first eggs are laid for the 

 next brood. If the adults all came out together, and the eggs all hatched about 

 the same time, we might hope to gain control with ordinary measures but the 

 period of egg laying extends through September, according to Professor Slinger- 

 land, therefore all measures except that of hand digging or "worming" must be 

 extended over long periods.* 



REMEDIES. 



The time honored measure of digging away the earth from the crown and of 

 making a careful examination of each tree, has never been superseded by one 

 more effective to say the least. The removal of the iarvas in the spring or fall 

 by the knife, of course settles the matter for the time. The presence of the larvae 

 usually is indicated by a mass of gum. Professor Slingerland in his exhaustive 

 work on this insect, describes how he tried every thing that seems to have been 

 recommended for this pest, and succeeded in finding a long list of useless 

 "remedies." He found, however, that tobacco waste placed close to the tree, at the 

 level of the soil, did prevent a good percentage from gaining lodgment. He also 

 obtained partial immunity by wrapping paper about the crown and lower trunk 

 and tying with an ordinary string. 



The writer has been assured by several peach raisers in Western Michigan that 

 the practice of digging away the soil from the upper roots, where the worms 

 burrow, in June, results in destroying the larvas and pupae, the sun shining directly 

 on the parts and killing the tender creatures. The soil is turned back in mid- 

 summer by the ordinary cultivation. Still others practice, heaping up the soil 

 about the trunk for eight or ten inches in the spring thus inducing the larvae to 

 work high up. These banks are removed in the fall and the trees wormed in the 

 ordinary way. 



* Bui. No. 176, Cornell Exp. Sta., Dec, 1899. 



