ROUND-HEADED APPLE TREE BORER 



69 



Control. Encourage the presence of woodpeckers. Cut borers 

 out when discovered, if possible, without seriously injuring the 

 tree. Place limbs in the sun around the orchard to attract the 

 beetles during the egg-laying period. Burn this infested wood 

 the following fall or winter. Practice clean culture and proper 

 pruning. Plant healthy stock. See also remedies for round-headed 

 borer. 



The Round-headed Apple Tree Borer. (Saperda Candida Fab.) . 

 The adults have two dorsal white lines on the back (Fig. 92). 



Life History and Habits. Adults appear in spring and summer. 

 Females oviposit in incisions in the bark made with the mandibles. 



FIG. 92. Round-headed apple tree borer; a and b, two views of the larva; b, pupa, c, adult. 

 (U. S. Bu. Ent., U. S. Ag.) 



The puncture is then closed with a gummy fluid. The pale- 

 brownish eggs are placed singly. The time required for hatching 

 is in doubt. The larvae work inward and feed on the sap wood, 

 working up and down the tree. After resting during the winter, 

 they resume action in the spring. They work into the heart wood 

 during the second season, spending their second winter as larvae, 

 and entering the pupal stage during May and June. They emerge 

 as adults about two weeks later. Two years, therefore, are re- 

 quired to reach the adult stage. 



Control. Cut out larvae when possible. To prevent egg- 

 laying in the bark, paint the trees in the spring with a mixture 

 of soft soap and carbolic acid. Boil one quart of soft soap or 

 one pound hard soap in two gallons of water; then add one pint 



