Abstract: Caragana korshinskii is a major sandfixating plant species in arid and semiarid regions of China, while Kytorhinus immixtus, Etiella zinckenella, and Bruchophagus neocaraganae are the dominant seed pests of C.korshinskii. Selecting the C.korshinskii shrubberies in three habitat types of manually fixed sandy land, mobile sandy land, and sandy loam hilly land in desert steppe of Ningxia as test objects, an investigation was made on the spatial distribution characteristics of the three dominant seed pests of C.korshinskii in the patches of different areas, with the relationships between the seed pests spatial niches and the patch area analyzed. In the habitat of sandy loam hilly land, the vertical distribution of the pests in C.korshinskii shrubbery was in the order of canopy layer (38.9%) > middle layer (33.9%) > bottom layer (27.2%), and the horizontal distribution was in the sequence of western sector (31.0%) > northern sector (29.3%) > southern sector (21.7%) > eastern sector (18.1%) of the shrubbery. K. immixtus and B. neocaraganae mainly distributed in the canopy layer, while E. zinckenella mainly distributed in the middle layer. In most cases, one pod was only occupied by K. immixtus, B. neocaraganae, or E. zinckenella. It was quite rare that two or three species of the seed pests lived in the same pods. In these cases, one individual occupied a bean. E. zinckenella had the highest vertical and horizontal niche breadths (0.977 and 0.917), followed by B. neocaraganae (0.959 and 0.829), and by K. immixtus (0.773 and 0.690, respectively). No significant differences in the niche breadths of the three seed pests were observed among the three habitats, and there was no significant correlation between the niche breadth and patch area.

Key words: Amorphophallus xiei, energy partitioning, fluorescence characteristics, light intensity, photosynthetic characteristics.