Diel activity patterns in an arable collembolan community

Diel patterns of activity and abundance among soil-surface Collembola in a wheat crop in southern England were investigated in summer using pitfall trapping, suction sampling and sweep-net sampling. The multivariate technique principal response curves (PRC) analysis was used to investigate changes in the overall community composition within and between sampling dates. Catches of Collembola obtained using all three sampling methods were generally highest from 12.00 to 00.00 h and lowest from 00.00 to 06.00 h, but diel patterns varied among species and were more variable for pitfall than suction samples. Pitfall catches of Lepidocyrtus cyaneus and also of the total Collembola were correlated positively with soil-surface temperature. The above-ground abundance of Arthropleona estimated by suction sampling varied by ca. 870 m(-2) in a 24-h period, suggesting that availability of Collembola to predatory arthropods could change considerably in a short time. These findings have implications for arthropod sampling strategies. exposure of Collembola to agrochemicals and predation of Collembola in agroecosystems. (C) 2001 Elsevier Science B.V. All rights reserved.