Season and Soil Moisture Effect on Movement, Survival, and Distribution of Cyrtomenus bergi (Hemiptera: Cydnidae) within the Soil Profile

A field experiment was carried out to elucidate movement of the burrower bug, Cyrtomenus bergi Froeschner, and its distribution in soil profiles under dry and rainy season soil moisture conditions. By combinations of dispersal restrictions we demonstrated that flying, walking on the soil surface, and shallow burrowing were all equally important ways of dispersal for insect adults during the rainy season. During the dry season, however, burrowing was inhibited, but flying and walking on the soil surface were significant. Nymphs dispersed by walking on the soil surface while burrowing capacity was low. Damage caused by C bergi feeding did not vary between the 2 seasons, and the habitat of both adults and nymphs remained between the surface of the soil and 20 cm below. Interaction between vertical distribution and seasons was due to low survival at 0-10 cm during the dry season. The relatively higher abundance at 10-20 cm during the dry season was explained by low survival at 0-10 cm; this result contradicts previous suggestions that the higher abundance was due to downward movements.