DRAGOOTUES AND DAMSEI^I^UES IN PONDI^ISH CULTURE. 



Imago. — In these latitudes the winter is passed in the nymph stage, and toward 

 the close of the following spring the nymph, having passed through successive molts, 

 is ready for transformation. This is accomplished by crawling out of the water onto 

 some convenient object near at hand, to which it fastens with its claws. In a short 

 time the skin splits across the top of the head and then along the back and the imago 

 or perfect insect emerges, leaving the old nymph skin, called an exuvia, fastened to its 

 support. 



TenkraIv. — After emerging, the imago is of a uniform pale yellow or tinged with 

 blue, brown, or white, and it takes from a few hours to several days for it to acquire the 

 bright colors of the mature adult. During this time it is called a teneral, its body is soft 

 and flabby, its wings shine as if varnished, and its powers of flight are quite limited. 



longipennis; length, 0.90 mm. Fig. 5. — Nymph of Packydiplax longipennis after the first moult: length, i mm . 



PruinosE. — After becoming thoroughly hardened, some species, especially the 

 males, are gradually covered with a bluish or whitish powder which may hide entirely 

 the original bright colors; they are then said to be pruinose. 



In Plathemis lydia the old males are almost white on the dorsal surface; in Erythemis 

 and Pachydiplax they become blue; while in the damselfly, Argia putrida, the thorax 

 and the last two segments of the abdomen appear to be blue, but this color disappears 

 at once when they are put in alcohol. 



MOUTH PARTS OF ODONATE NYMPHSo 



Dragonfly Nymphs. — In dealing with the food of nymphs and adults we need to 

 know a little about the means which they possess for seizing, eating, and digesting their 

 prey ; let us begin with the mouth parts. 



