﻿114 THE ENTOMOLOGIST, 



keeping the food fresh and the larvao on their food. It is happy 

 this is 80, as it greatly Bimplifies the treatment of very small 

 and newly-hatched larvae. Considering that newly-hatched 

 larvae of all but the largest of the British Lepidoptera will easily 

 walk through muslin, and that the tendency of most species is 

 to scatter directly they hatch, it is obvious that it is necessary 

 to have almost air-tight receptacles if large numbers are not to 

 be lost. Then, again, newly-hatched larvae generally require 

 tender foliage which quickly wilts in the open, and the constant 

 changing of the food of such young larvae is almost impossible 

 without loss. Now a glass-topped metal box of suitable size 

 meets both these difficulties admirably. Kept tightly shut — I 

 sometimes even use an elastic band round the join in the lid — 

 leaves will keep sufficiently fresh for days, sometimes for over a 

 week ; and there is certainly no fear of the larvae escaping. The 

 necessity of moving the larvae until they have at any rate 

 changed their first skin is thus obviated. The main trouble to 

 guard against in glass-topped metal boxes is mould ; if the boxes 

 are thoroughly cleaned and sterilized before use, and care is 

 taken not to put in food the slightest bit damp, it will be a long 

 time before mould appears. Another good thing is to have 

 plenty of boxes, so that when it is necessary to change the food 

 the larvae and the fresh food can be put in a fresh box. How 

 long young larvae should be kept in such boxes of course depends 

 on their rate of growth, their ultimate size, and the number in 

 each box. Small Geometers can be fed right up by gradually 

 increasing the size of the box used and putting fewer in each 

 one ; soft Noctuae larvae are best moved out of the boxes as soon 

 as they get from ^-in. to ^-in. in size. When the larvae are first 

 hatched I believe in using the smallest box suitable, and putting 

 in the food so that it touches the glass lid when the box is shut. 

 My reason for this is that newly-hatched larvae have a tendency 

 to go to the highest point and stay there — doubtless due to their 

 instinct to get to the tenderest leaves— and, further, they require 

 to be kept close to their food, or many will die before they start 

 feeding. After the first instar this is not so important, though 

 the keeping of larvae fairly in touch with their food is a point 

 which should not be lost sight of in all stages of growth. 



Fresh Food. 

 With the exception of the larvae of a few species who delight 

 in wilted leaves and others who revel in decaying matter, fresh 

 food is most essential to the successful rearing of most larvae 

 and particularly of those newly hatched. When using the word 

 " fresh "it is meant in its literal sense, i. e. in growing con- 

 dition. Many larvae, which feed on the foliage of hard-wood 

 trees and shrubs and some of the stronger-growing hedgerow 

 plants, will do well if the stems of their food are kept in water 



