59 



growing before they curl up into pupae. Insects are rarely active in 

 the pupa stage. The mosquito is one of the very few exceptions. 

 From these lively pupae the full-grown mosquitoes emerge. Figure 20 

 shows a small glass tumbler in which the three aquatic stages of the 

 mosquito's life are seen and an adult just leaving the pupa skin. 

 Nothing is easier than to watch the entire de- 

 velopment of the mosquito, and the charhges 

 must be seen to be fully enjoyed and appreciated. 

 It would be interesting to note the differences 

 between the mosquitoes that come out of the 

 small aquaria. A supply of wigglers should be 

 kept in the permanent aquarium as food for 

 the other insects. 



Every child knows the dragon-fly or darning- 

 needle, and none but the bravest of them dare 

 venture near one, without covering ears or eyes 

 or mouth for fear of being sewed. There is 

 no more wide-spread superstition concerning 

 any insect than this one, and it is difficult to 

 bring children to believe that this creature, be- 

 sides being a thing of beauty, is not only harm- ^ ^^ ^ ^ 



00 J •> J viG.zo.- 1 emporary aqtiari- 



less but actually beneficial. If they knew how nm, containing eggs, lar- 



^11 . n ^ . viE, and piipte of mosquito. 



many mosquitoes the darning- needle eats in a t t j ■/ 



day they would welcome him, instead of fearing the gay creature. 



The young of the dragon-fly live a groveling existence as different 

 as can be from that of their sun-loving parents. Their food consists of 

 mosquito larvae, water-fleas and the like, and their method of catching 

 their prey is as novel as it is effective. Pupils and teacher can get 

 plenty of good, healthy entertainment out of the behavior of these 

 awkward and voracious little mask-wearers. The first dip of the net 

 usually brings up a supply of dragon-fly nymphs and of their more 

 slender cousins the damsel-fly nymphs. The latter have expanded 

 plate-like appendages at the hind end of the body which distinguish 

 them from the dragon-fly nymphs. 



The transformation of one of these young insects into an adult is one 

 of the most interesting observation lessons that can be imagined for a 

 warm spring morning. If a dragon-fly nymph should signify its inten- 

 sion of changing its form in my school room, I should certainly suspend 



