1868.] 



15 



T know to the contrary, the school-boy's old romody of resuscitating drowned flies 

 by covering them up with salt and exposing them to the rays of the sun might 

 prove effective, only I have my doubts as to the effect of damp salt on larval 

 surfaces. 



Starvation. This may depend on defective supply of food, or the use of an 

 improper diet, or the presence of excess or deficiency of light, as the case may be, 

 may cause the subject of it to sulk and pine away. The treatment is, generally 

 speaking, obvious enough, but sometimes we find larvae feeding well enough for a 

 time on some particular kind of food, and then unaccountably falling off their 

 appetite ; under such circumstances change of diet should be tried, ventilation, &c., 

 should be attended to, light (and even in some cases, rays of the sun) should be. 

 admitted ; rinsing the food in fresh water, or exposing it to a shower of rain : and 

 as many larvas have a predilection for sweets, the food may be washed with syrup 

 and allowed to dry, or sugar or treacle may be added to the contents of the water 

 vessel Tvith a view to imparting a flavour to the food ; in the latter case, however, 

 we must be careful that the mixtm-e become not mouldy or acetous. 



Surfeit. Many larvae, especially such as are large and smooth, when per- 

 mitted to gorge themselves with too juicy food, have a tendency, particularly when 

 about three-quarters grown, to become dropsical and die. The remedy would 

 appear to be to feed them on dry mature leaves gathered from bleak exposed 

 situations, and moisture should be excluded from the cage. 



Cramp. A night passed on a cold surface is often sufficient to paralyse the 

 pro-legs of larvae, especially of such as are young and tender ; under these circum- 

 stances they are unable to retain their hold when placed upon their food : perhaps 

 the best plan is to put them on some such surface as a piece of blotting paper, in 

 a temperate situation, fresh leaves of the food-plant being strewn about within 

 reach of the sufferer. 



Low Fever. Undoubtedly larvae suffer from a contagious disease very 

 analogous to this. Some species are more liable to it than others, and it appears 

 to be very fatal among the members of any affected batch, though apparently not 

 communicable from one to another, and distinct, species. It is doubtless engen- 

 dered by bad feeding, ill ventilation, proximity of decaying vegetable or animal 

 matter, &c. ; the indications therefore are that these should be removed as early as 

 possible, and the healthy larvae should be kept separate from those which show the 

 slightest signs of the disease. The use of a small quantity of Condy's disinfecting 

 fluid in the water vessel, too, could do no possible harm, and might prove beneficial. 

 Somebody has suggested that immersion in cold water has a beneficial effect in this 

 disorder. 



Irritability. Some larvae are naturally of a waspish, irritable disposition, 

 biting and striking violently at anything or any other larvae which may cross their 

 path or come in contact with them ; others become ill-tempered during, and for a 

 short time after, their moults, when the skin appears to be very sensitive ; or this 

 irritable state may be due to the recent sting of ichneumons, the presence of 

 acari, &c., requiring our attention. Larvae thus affected should be kept as little 

 crowded as possible, and, indeed, if necessary, confined in separate cages. 



