Michal Knapp has recently published a study in the journal Biological Conservation showing that the data (species lists) produced by pitfall traps are seriously biased. Pitfall traps record approximately 50% less ground beetle species than the hand searching technique (https://doi.org/10.1016/j.biocon.2020.108545). Species with specific characteristics (small, phytophagous, well-flying species) remained undetected. Pitfall traps typically ignore species with higher conservation value, which limits the direct negative impacts on their populations but can pose fatal indirect consequences (for example, biological surveys that do not reveal red-listed species can result in the approval of building construction leading to complete habitat destruction). The most efficient way to record complete insect communities in the field is to employ simultaneously multiple complementary sampling techniques.
