116 WORK AT HOME AND IN THE FIELD 



siTspencl themselves from the food plant itself. It will be seen tliat the 

 larva cage just described supplies all these demands, and care must be 

 taken not to disturb the occupants while they are undergoing their 

 metamorphoses. Those that suspend themselves on the food plant 

 should be allowed to remam where they have fixed themselves, and 

 when it is necessary to remove the stale food in order to give a fresh 

 supply to the later larvse, let it be fixed in an airy place where it can 

 be watched till the perfect insects emerge. Those which suspend 

 themselves on the sides or top of the cage, or spin cocoons in the 

 corners, should never be disturbed unless you are greatly in want of 

 the same cage for the accommodation of another brood ; and even 

 then it is possible that their presence will not in any way interfere 

 with the new species. But if their removal becomes a necessit}-, let 

 it be carried out as carefully as possible, and not until the change 

 to the pupal stage is known to be complete. 



The species that burrow into the soil or bury themselves in the 

 moss need never be disturbed till the rearing season is quite o\er, 

 and then they may be transferred to a box specially kept for the 

 accommodation of pupae. 



There is yet another method of rearing larvie to which we must 

 refer— a method known as ' sleeving ' — particularly useful when 

 you happen to have the required food plants in your own garden. 

 The ova or larvae are placed on the plant, the whole or part of 

 which is then covered with a bag or ' sleeve ' of gauze. The larvae 

 thus imprisoned have the full benefit of fresh air and light, and 

 are also free from the attacks of ichneiimon flies. They have a 

 fair amount of liberty, and yet cannot get beyond your reach ; 

 also abundance of fresh food without further trouble on the part of 

 the rearer. 



But even this arrangement is not perfection. It will not suit 

 the night feeders that like to hide beneath the soil during the da,y, 

 and it interferes somewhat with the burrowing tendencies of those 

 which pupate underground. These little difficulties, however, can 

 be overcome by placing the food plants in large pots or tubs of 

 soil, and tying the mouth of the ' sleeve ' round the outside of this 

 utensil. If this cannot be done, those insects that pupate under- 

 ground nuist be removed from the plant when their restless 

 disposition shows that the changing time has arrived, and then be 

 transferi-ed to a box of soil where tliey can find the seclusion they 

 seek. 



The larvie that hvbernate throughout the winter are rather 



