The Odonata or Drayonjiies of South Africa. 269 



Eeceut observations by Dr. Wesenberg-Lund give us a good iusight 

 iuto the reasons why species of Lestes may be particularly fit to exist 

 under conditions not otherwise favourable for dragonfly life. The 

 European species observed by tliat author hibernate as eggs (which 

 are concealed and protected in plant tissues, where they are inserted 

 by the female) ; when hatched at the beginning of the warm season 

 they develop with astonishing rapidity, reaching the imagiual state in 

 a few weeks. Thus they do not strictly need perraaueut water, and 

 may exist in regions where great drought prevails and suitable water 

 is only available for a comparatively short period of the year. Lestes 

 larvae are exceedingly slender, half transparent creatures, jerky aud 

 swift in their movements, voracious feeders ou Crustacea and small 

 larvae of Ephemeridae and Diptera, as may be expected from their 

 rapid growth and development. Our Plate XII, fig. 1, photographed 

 from the European Lestes virens, will give an idea of their general 

 appearance. 



1. Thoracic dorsum yellowish, olivaceous or reddish brown. No metallic 



green or black stripes. Superior ajipendages of male forcipate . 2. 



Tlioracic dorsum greenish, olivaceous or reddish brown with dark or 

 metallic green stripes . . . . .3. 



Tlioracic dorsum black, with tluee (one medial, two humeral) reddish 

 brown lines ; ventral siu-face of thorax black. Pterostigma rectangular, 

 narrow, reddish brown, yellowish in the distal third. Superior appendages 

 of male forcipate. Small species. (Female unknown.) . Wahlbenji. 



2. Venation mostly ochre yellow. Pterostigma very light yellowish. No 



dark markings on thorax, not even on ventral surface . . ictericus. 

 Venation dark. Pterostigma reddish brown. On ventral surface of 

 thorax a very distinct black point each side near the ventral and 

 anterior angle of metepimeron. Somewhat variable other daik markings 

 on thorax; four (or six) dark brown points on dorsum, a narrow brown 

 stripe on mesepimeron ........ nchracens. 



3. Thoracic dorsum greenish or olivaceous with a broad median black or 



slightly bronzy band, joined laterally to three rectangular spots. Wings 

 hyaline or very slightly tinged with yellow. Pterostigma very dark 

 brown, slightly dilated in the middle. Superior appendages of male 

 very long, whitish with black tips, their distal third strongly curved 

 downward ........... uncifer. 



Dark or light markings of thoracic dorsum straight lines ... 4. 



4. Thoracic dorsxuu ferrugineous, with two lines of brilliant metallic green in 



males and immature females, darkei-, bronzy or coppery in mature 



females. 



Wings strongly tinged with yellow ; pterostigma dilated in the middle. 



Superior appendages of male forcipate ...... 5. 



Thoracic dorsum as in (5) in females and immature males, black with a 

 narrow median line and broad humeral bands greenish in adult males. 



