Collecting Insects. 5 



kind of larva from which any given adult comes. There are many 

 adult insects whose larval stage is unknown, or little understood. 



When a caterpillar or other larva is taken, the collector should 

 note on what it is feeding, and it should be supplied with the 

 same, or very similar, food, as long as it continues to eat. If 

 the larva is not on any plant, but is crawling over a walk or on a 

 fence, it may be because it was shaken off the plant on which if 

 was feeding ; very often, however, the larva, when thus found, has 

 done eating and is seeking a convenient place to go into the pupa 

 stage. If so, it will not need food. It is safe to offer food in any 

 case. 



Larvae should be kept in roomy cages. And, since many larvae 

 go into the soil to pass their pupa stage, it is best to provide soil 

 for any larva whose habits are not known. A convenient breeding 

 cage may be made of a starch box by sawing off about one third 

 of the length of the wooden cover and sliding it into the farthest 

 end of the top. Then set the box on end, with this covered part? 

 down, and fill with soil as far as the wooden cover extends. Cut 

 a glass cover to slide in and fill the rest of the opening ; make 

 a hole for ventilation and cover it with wire screen. If a larva 

 that does not pupate underground is reared in such a box, no 

 harm will result. It is well to have several such boxes in readi- 

 ness for the work. A jelly tumbler serves very well as a breeding 

 cage for small insects. A lamp chimney may be used as a breed- 

 ing cage ; tie netting over the top. 



PRESERVATION OF INSECTS. 



Pinning. Most insects are mounted upon a pin passed 

 through the center of the thorax. One third of the pin should 

 project above the back. Beetles are usually pinned through the 

 right wing cover, at such distance from the base of the wing that 

 the pin emerges between the second and third pairs of legs. It is 

 better to get regular insect pins, which are to be obtained from 

 dealers in naturalists' supplies. Common pins may be used, but 

 they are likely to rust. Medium-sized insect pins are best for 



