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INJURIOUS INSECTS AND FUNGI. 



[March 1895. 



Eggs are placed by the female by means of its ovipositor 

 in small groups in the cracks in the bark of the trees. A 

 female will lay from 400 to even 1,000 eggs, so that it is for- 

 tunate that this moth is not particularly abundant. Its egg is 

 broadly oval in shape, dusky in colour, and about the size of a 

 clover seed. Some persons hold the idea that the moth lays eggs 

 by preference upon trees that are in an unhealthy state or 

 decaying ; but this is erroneous, for it has been proved that the 

 soundest trees are attacked. 



In about seven or eight days, the larva comes from the 

 egg, and at first feeds upon the rind and inner bark. As 

 it gets older, it works its way further inwards. It tunnels 

 in a longitudinal direction. The inside of the tunnel, or 

 mine, is generally covered with a black layer composed pro- 

 bably of excreta and wood dust. In its earlier stages, the larva 

 is pinkish in colour, gradually becoming darker until when fully 

 developed it is almost mulberry coloured on the back with a 

 shade of pink on its sides, and a yellowish shade below the 

 spiracles. There are a few long fine hairs upon its body. The 

 head is flat and black ; on the second segment there is a large 

 horny plate. It has very powerful jaws, adapted specially for 

 biting hard substances ; and six pectoral legs, brown in colour, 

 .and eight light pink prolegs furnished with hooks, and two 

 ;anal feet. 



The caterpillar lives for three years. At the end of this 

 period it approaches the hole or exit of the tunnel, and at 

 some distance from it forms a cocoon of silk and morsels of 

 wood in which the pupal state is assumed. A caterpillar which 

 was put in a paper glass-topped case, instead of gnawing its way 

 ^out, was found coiled in a ring in a corner and covered with silk 

 and paper bitten off the sides of the case. 



The pupa is about an inch and a quarter long, of cylindrical 

 shape, reddish-brown in colour above, but rather lighter below. 

 The segments are furnished with rows of teeth. By means of 

 these, the pupa when it is changing moves itself to the mouth of 

 the tunnel and the perfect insect escapes. Occasionally, cater- 

 pillars leave the trees and are seen crawling on the ground, or 

 are found in cocoons of silk and dirt in the earth. 



Prevention and Remedies. 



When infestation is ascertained by the exudation of sap from 

 places in the tree, the collection of " frass " at the mouths of the 

 holes, or tunnels, or the protrusion of empty cocoons from them, 

 a sharp look out should be kept for the moths. They are dull, and 

 heavy in flight, and rest during the day on trees, palings, &c. ; 

 and may be discovered by persons with good eyes, and should 

 be ruthlessly destroyed. Latreille advises that the lower parts 

 of the stems of trees in infested localities should be smeared 

 with a mixture of lime- wash and cow- dung to prevent the 

 females from laying eggs there. According to a receipt given 



