CYDNIDAE OF THE WESTERN HEMISPHERE — FROESCHNER 357 



to have extended its range into this hemisphere, where it is represented 

 by the single species treated below. 



In habits the members of this genus are quite different from other 

 cydnids. The species of Sehirus are not burrowers and root-feeders, 

 the common trait that suggested the popular name of "burrower 

 bugs" for these insects. Instead, nymphs as well as adults of Sehirus 

 feed on plant parts above the ground. This has exposed their 

 activities to observation and enabled students to report more ecological 

 data for them. Although the life history of the single New World 

 species has not been worked out, the reported fragments of it agree 

 well with the biological studies on European species by Boselli (1932), 

 Southwood (1949) and Southwood and Hine (1950). A generalized 

 life cycle has been extracted from the latter paper and incorporated 

 in the family discussion (p. 351) of the present study. 



Sehirus cinctus (Palisot de Beauvois) 



Plate figures 19, 86, 130, 138, 188 

 Pentatoma cincta Palisot de Beauvois, 1805, p. 114, pi. 8, fig. 7. 



Diagnosis. — This is the only species of the genus known to occur 

 in the Western Hemisphere. The narrow, creamy white margins 

 of pronotum, corium, and abdomen suggested as a ready means of 

 identification of the genus in the New World will serve also to deter- 

 mine this species. 



Description. — Color: Brownish black, black, or bluish black, coria 

 usually slightly lighter, narrow side margins of pronotum, costae, 

 edges of sternite II to V, edge of subgenital plate of male, last tergite 

 of female, and elongate dash on dorsal face of each tibia creamy 

 white; antennal II, rostrum, and tarsi yellowish brown. 



Male : Oval, broader to posterior of midlength. 



Head: Longer than wide; juga reaching or surpassing apex of 

 clypeus, latter slightly narrowed toward apex; margins of juga 

 variously reflexed; surface, except vertex, with numerous close-set, 

 coarse punctures, these more or less confluent into radiating lines 

 toward margins of head; juga ventrally polished, impunctate; 

 maxillary plate distinctly punctured; antennal and labial lengths as 

 given in subspecies descriptions; bucculae reaching nearly to base 

 of head, evanescent posteriorly. 



Pronotum: Length less than half of width; transverse impression 

 weak to moderately impressed, marked by a broad band of numerous, 

 distinct punctures continuing finer and sparser over posterior lobe; 

 anterior lobe distinctly and abundantly punctured except on calH; 

 both lobes with minute punctures interspersed between coarser ones. 



Scutellum: Longer than wide; surface mostly punctured, more 

 finely so at apex. 



