LEPIDOPTERA AND HYMENOPTERA. 25 



them at work. For anybody who takes a lively interest in natural 

 history, there can scarcely be a more fascinating pursuit than 

 watching from night to night the life-history of these insects. 

 You increase your acquaintance every day by fresh discoveries. 

 Old friends drop off and new ones take their place. You know 

 at any time where you are sure to find specimens of a certain 

 species ; you miss each of them regularly for a day or two each 

 week or ten days when they are changing their heads and skins, 

 and hardly recognise them at first when they return in their new 

 attire. 



I have been speaking only of flowering plants, but every tree 

 and shrub has hundreds of larvce if we will only have the patience 

 and can spare the time to find them out, and each of them has a 

 life-history of its own full of marvels. Much may be done in this 

 way by a systematic investigation at night with a lantern, but if 

 there are many trees and bushes to be examined, and that con- 

 tinually— ■a.'?, larvfe of fresh species hatch out weekly, daily, or even 

 hourly — it is very desirable to have some indicator by which, 

 without even taking the trouble to find the larvse themselves, you 

 may know they are there, and can watch their growth from day to 

 day. My method for gaining this end is a simple and inexpen- 

 sive one. Instead of throwing the newspaper away after being 

 read, it is placed under a shrub or tree, wherever there is a chance 

 of larv«. This is repeated every day until you have a newspaper 

 spread out under all those plants, shrubs, and trees you care to in- 

 vestigate. On going your rounds in the morning you find on most 

 of these papers hundreds of small black pellets, the excrementa 

 or frass of the larvs feeding on the shrub in question. It is not 

 difficult to find many of the larvae at once, but there is no need 

 of that, as they are very small. It is sufficient to watch the 

 pellets as they increase in size day by day, and, with a little prac- 

 tice, it is often easy, without ever having seen the larvse, to deter- 

 mine their species from the time of year and the food-plant : — As 

 soon as the pellets become large, or they have been observed for 

 about a month, it is time to find the larvae and remove them to a 

 breeding cage, in which a spray of the food-plant is kept fresh in 

 a bottle of water, if you wish to continue your investigation to the 

 pupa and imago stage. By this means many thousands of larvse 



