444 



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

 abdominal segments two to six nearly transparent; wings becoming 

 transparent ; stigma faint, hardly noticeable. 



10:35. N° 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. 



2:00 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 

 flying along the streams or about the lakes, ponds, or marshes in 

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

 near woodland marshes ; Hetaerina and Argia are most commonlv 

 encountered near rapid streams, while the remainder of the Illinois 

 representatives of the suborder may usually be found near small 

 lakes, ponds, or sluggish streams. 



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

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

 larity. The vibration of the wings is much 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- 



