title: Obtaining valid population indices from pitfall trapping data.
mesh_terms: D000818:Animals; D001070:Appetitive Behavior; D001517:Coleoptera / Q000502:physiology*; D007915:Lepidoptera / Q000502:physiology*; D009036:Moths / Q000502:physiology*; D011156:Population Density; D011235:Predatory Behavior; D012107:Research Design; D012621:Seasons