ORTHOPTERA. 



121 



easily recognized by the accompanying figure, which represents the 

 insect natural size. They make burrows in moist places from six to 

 eight inches below the surface of the ground, and 

 feed upon the tender roots of various plants. 

 In Europe, where mole-crickets arc more abun- 

 dant, they are frequently serious pests in culti- 

 vated fields ; and in the West Indies there is a 

 species which is very destructive to sugar-cane. 

 The species of Triddctylus resemble Gryllotalpa 

 somewhat in form, but are very much smaller; 

 our species are all less than 10 mm. (0.4 inch) in 

 length. They also resemble the large mole- 

 crickets in habits, burrowing in similar places. 

 But they differ in having their hind legs formed 

 for leaping, and are able to jump as well as the 

 true crickets. At Ithaca we find Tridactylus 

 very local in its distribution. A large number 

 of specimens have been taken from a small FlG - Io8 ; — C'-yihtaipa 



1 borealis. 



spot on the margin of one of our streams, but 



a most careful search has failed to reveal its presence elsewhere in 



our region. 



The True Crickets. — The true crickets abound everywhere, in 

 pastures, meadows, and gardens; and certain species enter our 

 dwellings. They are chiefly solitary, nocturnal insects ; yet many 

 can be seen in the fields in the daytime. They usually feed upon 

 plants, but arc sometimes predaceous. The eggs are laid in the 

 autumn, usually in the ground, and are hatched in the following 

 summer. The greater part of the old crickets die on the approach 

 of winter ; but a few survive the cold season. The greater part 

 of the species of our true crickets are included in the two genera 

 Gryllus and Nenwbius. To the former genus belongs our larger 



species. The two larger of our 

 species are Gryllus luctuosus and 

 Gryllus abbreviates (Fig. \o%d). The 

 species of the genus Nemobius are 

 much smaller than Gryllus. and are 

 characterized by the greater length 

 of the last segment of the maxillary 

 palpi. The most common species, 

 and one that is very abundant in our fields during the latter part 

 of summer and autumn, is Nemobius vittatus. 



Fig. ioSrt. — Gryllus abbreviatus. 



