Field crickets were collected from 1980 to 1981 at five localities of Korea and classified into spccies of the family Gryllidae. Five genera and 11 species including 5841 specimens were recorded. Ceographic variation of the adult size(head width and body length) increases from north (Gangneung city) to southward(Jeju Island) in Teleogryllus emma. Mean developmental day of eggs collected from five localities was positively correlated with the original latitudr. The time from egg to nymphal emergence was 89.6 days at southern latitude of Jeiu Island, while it averaged was about 62 days at northern latitude of Seoul, Donghae and Gangneung. The nymphal emergence time of eggs in the species of T. emma was controlled by photo-period. In odor to elucidate the correlation between photoperiodic response and developmental time, the eggs laid on rotten wool plug were stored in refrigerator at 6$^{circ}C$, and the eggs were transferred to 26$^{circ}C$ after 20 days. Photoperiodic tests were carried out in five separate series. The eggs emerged in about 32 days at 16L : 8D, l4L : 10D and 12L : 12D. On the other hand, the eggs reared at the constant light(24LL) and constant dark(24DD) environments emerged in 45 and 55 days.