 Several studies seemed to indicate that some insect populations are in decline in the late 20th and early 21st centuries, and has also been popularized as the windshield phenomenon.For many studies, factors such as abundance, biomass, and species richness are often found to be declining for some, but not all locations in many studies; some species are in decline while others are not.Every species is affected in different ways by changes in the environment, and it cannot be inferred that there is a consistent decrease across different insect groups.