LIFE-HISTORY OF CHARAGIA VIRESCENS. 31 



best known, whose life-history I briefly describe in the following 

 paper. 



The larva of this insect, unlike most of its family, tunnels the 

 stems of living trees, feeding entirely on wood, which it bites off 

 with its strong mandibles. The plant most usually selected by 

 the caterpillar is Aristotelia racemosa, called by the settlers 

 "New Zealand currant," from its large clusters of rich-looking 

 black berries which appear in autumn ; in all other respects it 

 does not in the least resemble currant, reminding one more of a 

 tall cherry tree. Other food-plants are numerous, the "black 

 maize " {Olea apetala) and " manuka " {Leptospermium) being 

 among those more frequently chosen. This larva for the most 

 part inhabits the main stem of the tree, its gallery always having 

 an outlet to the air, which is covered with a curtain of dull 

 brown silk spun exactly level with the surrounding bark, and 

 consequently very inconspicuous ; these burrows usually run 

 down towards the ground, and are mostly two or three inches 

 from the surface of the trunk. In some instances the larv^ 

 inhabit branches, in which case, if they are of small dimensions, 

 the tunnels are made near the centre of each. These notes only 

 refer 'to galleries constructed by young larvae, as the tunnel made 

 by the insect prior to becoming a pupa is of a very complicated 

 character, and merits a somewhat detailed description ; it con- 

 sists of a spacious, irregular, but shallow, cavity just under the 

 bark, having a large opening to the air, which is entirely closed 

 with a thin silken covering almost exactly the same shape and 

 size as the numerous scars which occur at intervals up the 

 trunks of nearly all the trees. Three large tunnels open into 

 this shallow cavity ; one in the centre, which runs into the 

 middle of the stem ; and one on each side, which run right and 

 left just under the bark. These are usually very short, but 

 sometimes extend half-way round the tree, and occasionally even 

 join one another on the opposite side. The central tunnel has 

 a slightly upward direction for a short distance inwards, which 

 effectually prevents it from becoming Hooded with water ; after- 

 wards it pursues an almost horizontal course until it reaches 

 the centre of the tree, when it appears to suddenly terminate. 

 This, however, is not the case, for, if the gallery floor is carefully 

 examined a short distance before its apparent termination, 

 a round trap-door will be found compactly constructed of very 



