Abstract: Two sampling plots of the same area(22 m×22 m)with the alike stand were respectively selected within the samiliar pine stands in Jinsishan (JSS), Daigongshan (DGS), Jiulianshan (JLS) and Magushan (MGS) Forest Farms alone the south shore of Yangtse River in Anhui Province. Orthopterous insects in tree layer, shrub and herb layer, litter layer and soil layer were investigated in every month from Aug. 1998 to Jul. 1999. The results showed that: ①Catantops pinguis (Stal)was dominant in the 4 forest farms, and Locusta migratoria manilensis(Meyen), Atractomorpha sinensis I. Bolivar, Holochlora japonica Brunner-Wattenwyl and Gryllus testaceus Walker were common ; ② the number of species and of individuals,and the diversity index in DGS, JSS, MGS and JLS Forest Farms were 27, 159, 1.28 ; 26,70,1.32 ; 35,171,1.42 and 20,90,1.33, respectively; ③ all the insect species found and 80 % of individuals were in the shrub and herb layer; ④ plenty of herbs and streams in MGS Forest Farm provided good habitat for the orthopterans and the intensive spray of insecticides for many years favoured their development.It is suggested that heavy depression of their natural enemies by the application of the chemicals resulted in greater diversity and recovery stability of the orthopteran community in this forest farm than in the other ones.

Key words: massion pine forest, Orthoptera, temporal and spatial patterns, diversity, stability