650 



FAMILY VIII. GRYLLIDJE. THE CRICKETS. 



They differ also in having the fore trochanters much longer, the 

 free portion equalling the tibial dactyls in length ; hind tibiae 

 always armed above on inner margin as well as at apex.; basal 

 joint of hind tarsi ending on each side with a sharp spine, the 

 inner one the longer; apical third only of the hind tarsal claws 

 naked ; anal cerci shorter than pronotnrn. 



The habits of these smaller mole crickets are much the same 

 as those of the larger ones, but in tropical countries, where they 

 are much more numerous, they often do extensive damage to 

 crops- Barrett (1902) prepared a special bulletin on the damage 

 done by S. didactylus (vicinus Scudd.) in Porto Rico, estimating 

 the annual damage on that island at more than $100,000. All the 

 species feed on the roots, steins and leaves of living plants, espe- 

 cially those of cane, tobacco, rice and vegetables, growing in moist 

 places. The species are all tropical or subtropical in range, three 

 being recognized as occurring in our southern states. 



Fig. 214. Structures of Scaf-tcriscus. a, Lateral outlines of dactyls of front tibiae of 

 female, X 4! d, dorsal view of pronotum, X - : 9< lateral outline of fore trochanter or 

 spatula, X 4> all f $" I'icinits; b, e, h, same of .?. abbrcviatus; c, i, dactyls and fore 

 trochanter of 5 1 . acletns', f, lateral outline of terminal joint of hind tarsus and claws of 

 abbreviatiis, X 3-5! / dorsal view of -S". vicinns. (After R. & II. and Barrett.) 



KEY TO EASTERN SPECIES OF SCAPTERISCUS. 



. Dactyls of front tibise almost or quite touching at base; pronotum 

 without definite spots or figure of a distinct pattern (Fig. 214, a. 

 (?) ; ocelli obovate. 310. VICINUS. 



aa. Dactyls of front tibiae separated by a distance at least equal to one- 

 half their basal width; pronotum either with distinct spots or fig 

 ure of a definite pattern (Fig. 214, &. e) ; ocelli rounded or elongate- 

 oval. 



1). Tegmina covering only one-third of abdomen; pronotum and ab- 

 domen mottled with numerous large rounded pale spots; ocelli 

 very small, subrotund. 311. ABBREVIATUS. 



6&. Tegmina covering three-fourths of abdomen; pronotum and abdo- 



