BULLETIN 39, UNITED STATES NATIONAL MUSEUM. [112] 



i _J . 



THE HEARING OF INSECTS. 



General .Directions. The importance, even to the mere collector, of 

 rearing insects to obtain specimens for the cabinet has been referred 

 to from time to time in these pages. The philosophic' study of ento- 

 mology, however, requires much more than the mere collecting of 

 specimens, and one of the most profitable and, at the same time, most 

 fascinating phases of the study relates to the life-history and lial>its. 

 In no branch of natural history are biologic studies more easily carried 

 on, or the biologic; facts more remarkable or interesting. The syste- 

 matist by such study will be saved from the narrow and hair-splitting 

 tendencies which study of slight difference of characters tends to, 

 while to the economic entomologist it is most essential. 



In the rearing of insects success will be attained in proportion to the 

 extent to which the conditions of nature in the matters of temperature, 

 moisture, food- supply, and conditions for pupation, are observed. 



" In the hands of the careful breeder an insect may be secured against 

 its numerous natural enemies and against vicissitudes of climate, and 

 will, consequently, be more apt to mature than in a state of nature. 

 The breeding of aquatic insects requires aquaria, and is always at- 

 tended with the difficulty of furnishing a proper supply of food. The 

 transformations of many others, both aquatic; and terrestrial, can be 

 studied only by close and careful outdoor observation. But the great 

 majority of insect larvae may be reared to the perfect state indoors, 

 where their maneuveriugs may be constantly and conveniently watched. 

 For the feeding of small species, glass jars and wide-mouthed bottles 

 will be found useful. The mouths should be covered with gauze or 

 old linen, fastened either by thread or rubber, and a few inches of 

 moist earth at the bottom will furnish a retreat for those whieli enter 

 it to transform and keep the atmosphere in a moist and fit condition. 



The Breeding Cage or Vivarium. "For larger insects I use a breeding- 

 cage or vivarium which answers the purpose admirably. It is repre- 

 sented in figure 123, and comprises three distinct parts: First, the bot- 

 tom board , consisting of a square piece of inch thick walnut with a 

 rectangular zinc pan ff^ 4 inches deep, fastened to it above, and with 

 two cross pieces ## below, to prevent cracking or warping, facilitate 

 lifting, and allow the air to pass underneath the cage. Second, a box 

 b witlrthree glass sides and a glass door in front, to tit over the /inc 

 pan. Third, a cap c, which fits closely on to the box, and has a top 

 of fine wire gauze. To the center of the zinc pan is soldi-red a xine 

 tube rZ just large enough to contain an ordinary quinine bottle. The 

 zinc pan is filled with clean sifted earth or sand c, and the quinine 

 bottle is for the reception of the food plant. The cage admits of abun- 

 dant light and air, and also of the easy removal of excrement or truss 

 which tails to the ground; while the insects in transforming enter the 

 ground or attach themselves to the sides or the cap, according to their 



