NATURAL HISTORY SOCIETY OF GLASGOW. 147 



very few double brooded species. It seems, however, to be the 

 universal opinion that the larvae of Tenthredinidae and Cynipidae 

 are much more troublesome to rear than those of Lepidoptera ; 

 and it need scarcely be said that when their rearing is carried on 

 •in a large city, the difficulties of the investigation are enormously 

 increased. For instance, look how hard it is to get fresh food for 

 the larvae. 



Tree or bush-feeding larvae may be obtained by beating the 

 foliage ove;* an umbrella. For those feeding on ground plants a 

 sweeping net is requisite, but it must be handled cautiously, for 

 they do not bear much rough handling, and more success will be 

 had with larvae picked off the plants by the hand than with those 

 obtained by the net. Of course, before this can be done success- 

 fully, a knowledge must be gained, in the first place, of the food 

 plant; and in the second place, of the peculiar habits of the 

 larvae, which can only be acquired through observation and 

 experience. For example, some larvae, can only be found during 

 the night, never during the day time ; others have a peculiar 

 habit of resting curled up in a ring on the underside of the leaf, 

 scarcely visible at all from above; and whenever any thing comes 

 near, down they drop at once to the ground, where they are lost 

 among the herbage. With such species the only plan is to place 

 the open hand cautiously beneath the leaf and gently tap it, when 

 the creature will at once drop down. Searching by hand is not 

 always tedious work, for most larvae are more or less gregarious, 

 and wherever one is discovered more will without doubt be 

 found. 



Inter alia it may be noted that sawfly larvae devour the leaves 

 differently from those of Lepidoptera. They eat in a cleaner 

 manner, either making an oval or oblong cut in the edge, or in 

 the centre, and they cut through most of the nerves, while cater- 

 pillars eat the leaves in a ragged, irregular fashion, generally 

 leaving the nerves standing. By watching for these indications 

 of their presence, I have often been enabled to detect larvae 

 hitherto unknown to me. 



In attempting to rear larvae at home, the methods recommended 

 in such works as that of Knaggs, already referred to, will do. 

 The great secret is to keep the creatures in as natural conditions 

 as possible, but of course this is not always easy. Whether they 

 be kept in flower pots, jam pots, or bottles, they should not be 



