378 FOREST ENTOMOLOGY. 



from one tree together in a specially prepared cage, and then finally 

 arrange the perfect insects according to the respective trees from 

 which they have been hatched ; but, on the other hand, the special 

 portion of damage should be most carefully kept by itself, and the 

 perfect insects arranged together with the actual damaged portions in 

 entomological order. 



As time advances and the student makes progress, it will be ad- 

 visable to become more specific and less general. In fact, the correct 

 method of study would probably be to take a few special insects and 

 work them thoroughly out by means of study and observation. Having 

 regard to the shortness of human life, and the desire, or necessity, for 

 other subjects, the student of forest entomology must carry on simul- 

 taneously a number of observations with special insects and their 

 damage. Hence it is necessary to have separate hatching-boxes for 

 each species, but with regard to what is the best plan, individuals will 

 naturally differ from one another. The simplest plan, of course, is to 

 collect the larv?e just as they are about to change to pupse, for then 

 they require little or no attention. However, this is in many cases 

 practically impossible, and it must therefore be remembered that 

 ■moisture is invariably the most important essential in insect life. 

 This may be obtained either from a bed of damp sand placed in the 

 hatching - case, or from the food - plant itself. Hence two simple 

 methods may be given. The first is, simply to collect as many old 

 glass jam-jars, from a pint to a quart capacity, as may be required, 

 place a little damp sand in the bottom, insert a fresh potato in the 

 sand, stick the stalk of the food-plant into the buried potato, change 

 the food from time to time, lieep doion tJie mould, and patiently await 

 the results. Where moisture is not so absolutely important, as, for 

 example, in bark - beetles, the following plan Avill often suffice — viz., 

 get an empty negative or lantern-slide box, cut out a hole in the top, 

 leaving a little over half an inch of rim all round, get a spoiled 

 negative or lantern-slide (a by no means rare article in the hands of 

 an amateur), glue the cleaned glass to the rim left in the top, and you 

 then have a glass-covered box wherein you can place your specimen 

 and watch the results, noting daily all important points of develop- 

 ment, and tabulating the same in a note- and sketch - book kept 

 specially for the purpose. It may be well to remark that the 

 hatching referred to should, if possible, be kept in a shed or 

 outhouse. 



