444 



10:30. Wings 16 mm., abdomen 24 mm. Thorax grayish green; 

 abdominal segments two to six nearly transparent; wings becoming 

 transparent ; stigma faint, hardh' noticeable. 



10:35. No increase in length of the abdomen or wings; abdomi- 

 nal segments becoming dark near the sutures ; stigma of the wings 

 darker, now plainly noticeable; thorax olive-green; pronotum black. 



10:40. First two segments of the abdomen dark green ; segments 

 three to six pale green, the apical segments the same as the proximal 

 ones; thorax becoming steadily darker; first trial of the wings; the 

 insect is nearly ready to fly. 



10 :45. Fully able to fly, but still delicate and without full adult 

 coloration; no further increase in size of the abdomen or wings, but 

 growing steadily darker in color and indications of permanent adult 

 coloration becoming evident. 



10:55. Stripes of the thorax very distinct, though no blue or 

 other bright color has appeared ; very active and using its wings fre- 

 quently. 



12:00 M. Not yet fully colored, the two apical segments of the 

 abdomen beginning to show blue; the thoracic stripes of green not 

 fully developed. 



2 :oo P. M. Postocular spots distinct ; dorsum of abdominal seg- 

 ments eight and nine showing signs of the blue coloration. 



3 :oo. Insect fully colored and perfectly developed in every way. 



ADULT 



Habitat. — The adult Zygoptera are most frequently encountered 

 flving along tlie streams or about the lakes, ponds, or marshes in 

 which the nymphs aliound. Lestes is a frequenter of the thick woods 

 near woodkuid marshes; Hetaerina and Argia are most commonly 

 encountered near rapid streams, while the remainder of the Illinois 

 representatives of the suborder may usu;dly be found near small 

 lakes, ponds, or sluggish streams. 



Flight. — The flight is slow and uncertain, though frequently rapid 

 enough to enable the insect to avoid the collector with surprising regu- 

 larity. The vibration of the wings is mucli slower than that of the 

 Anisoptera, and is more like that of a butterfly. 



Mating Habits. — In summer, pairs of Zygoptera may be fre- 

 quentlv found flying together. The male grasps the female just be- 

 hind the prothorax by means of the anal appendages. The female 

 then doubles the body beneath the body of the male bringing the ovi- 

 positor in contact with the accessory genitalia of the second abdomi- 



