122 



Smith and Pritchard: Odonata 



basal plote 

 _ lateral plate 

 ovi positor 



genital valve 



Fig. 4:30. Ventral view of terminal abdominal segments of 

 female Aeshna. a, A. clepsydra; b, A. subarctica (Needham and 

 Westfall, 1955). 



the rest of their life. The eggs may be inserted in 

 the stem of an aquatic plant every two or three 

 seconds until the female is entirely submerged. 

 Rarely, an immersed log or even the sand or mud may 

 be used for egg deposition. 



Three years appear to represent the normal term of 

 life of an Aeshna naiad, representing seven immature 

 stages. Most naiads are found in fresh water that is 

 rather shallow and harboring aquatic vegetation. 

 However, A. californica has been recorded from 

 brackish water. Naiads of smaller dragonflies, water 

 beetles, mayflies, and aquatic bugs, as well as 

 leeches, tadpoles, and small fish, all serve as food 

 for the voracious naiads. 



Walker (1912) presented an excellent monograph of 

 • the genus Aeshna, but the later papers of Walker must 

 also be consulted. 



The California species fall into four distinct spe- 

 cies groups as far as the male terminalia are con- 

 cerned, but it is rather difficult to determine some 

 of the females with certainty. 



The following species are related to those recorded 

 from California, but they are not yet known from this 

 state: 



Fig. 4:32. Lateral views of male abdominal appendages in the 

 genus Aeshna. a, californica; b, interrupta; c, palmata; d, multi- 

 color (Celeste Green). 



Aeshna dugesii Calvert 1908, Baja California, Mexico, 

 and Texas (related to A. multicolor). 



Aeshna manni Williamson 1930, Baja California (related 

 to A. californica and misidentified by Calvert 1908, as 

 A. cornigera Brauer 1865). 



Aeshna arida Kennedy 1918, Arizona and New Mexico 

 (related to A. palmata). 



Key to California Species 



Males 



, Abdominal segment 1 with a ventral tubercle 2 



Abdominal segment 1 without a ventral tubercle .... 3 



. Superior appendage with a sharp ventral angulation or 

 spine near distal end (fig. 4:32<i) (British Columbia to 

 Wyoming, south to Texas and California and Panama) 



multicolor Hagen 1861 



Superior appendage without a ventral projection near 

 distal end (fig. 4:32a) (British Columbia and Idaho to 

 California and Arizona) californica Calvert 1895 



, Anal triangle with 2 cells; superior appendage without 



a distoventral tooth (fig. 4:326) 4 



Anal triangle with 3 cells; superior appendage with a 

 sharp, distoventral tooth (fig. 4:32c) 5 



, Mesothorax with dorsal pale stripes reduced to small, 

 isolated spots or narrow, incomplete lines (Canada, 



western U.S.) interrupta 1 Walker 1908 



Mesotkorax with dorsal pale stripes complete, expanded 

 at upper ends (U.S.) verticalis Hagen 1861 



Fig. 4:31. Types of lateral lobes of naiads in the genus 

 Aeshna. a, consiricta; b, canadensis; c, californica, multicolor 

 and verticalis; d, walkeri and interrupta; e, palmata and umbrosa 

 (Needham and Westfall, 1955). 



A. interrupta interna Walker 1908 (British Columbia, Oregon to 

 Colorado and New Mexico), a montane subspecies. 



A. interrupta nevadensis Walker 1908 (British Columbia, west- 

 ern Nevada, and California), a valley subspecies. 



