I 9 II.] 



The Cherry Stem Borer. 



829 



in crevices or cracks in the bark, usually close to the ground. 

 In one case where two main roots were partially exposed it was 

 noticed that all the eggs were deposited at the junction between 

 stem and root. I am not able definitely to state the number 

 of eggs; they are not all deposited together, but in isolated 

 groups. From observations made during the past three years 

 it would seem that they are not particularly numerous. They 

 hatch in from five to seven days. 



Immediately on hatching the larvae commence to feed upon 

 the bark, tunnelling beneath it and forming irregular cavities 

 by eating the inner bark and sapwood, sometimes penetrating 

 as deep as three to four inches. Their presence can be easily 

 detected by the holes made for extruding the frass. Exuda- 

 tions of gum are also noticeable on the trees, and not unfre- 

 quently fungi attack the exposed portions of the roots and 

 stems. 



The larvae become full fed about the middle or end of 

 August and pupate on the walls of the cavities. The full fed 

 larvae measure slightly more than half an inch in length, and 

 are usually of a pinkish white or fleshy colour ; occasionally 

 they are found of a creamy white colour or even very pale 

 brown. The moths appear in about fourteen days. About 

 the time the moth is ready to emerge the pupa pushes its way 

 through the bark. The pupa, which is enclosed in a cocoon, 

 is deep brown in colour. 



The eggs from this brood are laid in September, and the 

 larvae live beneath the bark until the following spring. They 

 continue to feed until the end of October, and commence again 

 at the end of March or early in April. 



Preventive and Remedial Measures. — Theobald 8 men- 

 tions amongst preventive measures smearing the trunks with 

 grease and paraffin, cow-dung or clay and lime, and thickly 

 coating the stems with pitch. Brushing or painting with 

 arsenate of lead and clay has not been found effective. 



My own experiments were designed with a threefold object, 

 viz., (i.) to make the surface of the stem obnoxious to the moths 

 in order to prevent egg laying; (ii.) to prevent the newly 

 hatched larvae from boring into the bark; and (iii.) to destroy 

 the larvae in the cavities beneath the bark. 



8 Tom. cit., p. 191. 



