Plum-Tree Boring Tortrix. 



167 



and the apical segments are somewhat darker than the rest. 

 When mature the larvae under observation measured over 

 half an inch. All were mature by the first week in May, 

 some having commenced to pupate on April 30th. The pupae 

 are brown, and are enclosed in a yellowish cocoon under the 

 bark. The moths commenced to hatch out on May 21st, the 

 pupal stage lasting nearly three weeks. 



This first brood soon commence to lay their eggs on the 

 bark of the trees. In six days a small larva appears and 

 ai once commences to burrow to the inner bark, in which it 

 tunnels and undergoes its development, pupating in August 

 and the early part of September. The second brood of moths 

 arises from these pupae, and lay their eggs again on the outer 

 bark. The winter is passed in the larval stage. The pupa pre- 

 vious to the emergence of the moth works it way to the exit hole 

 beneath the " trass/' and forces its way partly out of the 

 hole, so that the moth can easily escape from the ruptured 

 pupal skin. The creatures are very persistent in the attacks 

 on individual trees. 



Treatment, — Litcle can be done to prevent this pest, but 

 probably smearing cart-grease round the trunk, or, better 

 still, a mixture of grease and paraffin, from the ground some 

 way upwards during the middle of May would prevent egg- 

 laying, another application being made in September when 

 the second brood are egg-laying. 



When once under the bark little can be done. The 

 openings of the tunnels may be found on clearing away the 

 " frass/ 5 and a wire inserted up the cavity, or a knife forced 

 in, so as to kill the larvae during the winter. Where only a 

 few trees are attacked this is perhaps the best mode of 

 treatment ; on a large scale, smearing the diseased spots 

 with grease and strong paraffin and rubbing it well in 

 after the " frass" has been brushed off might be tried with 

 possible benefit. 



