Flying Insect Populations Have Dramatically Declined, New Study Says

Flying insect populations in German nature reserves periodically declined over a 27-year study, new research, published Wednesday by Radboud University in the Netherlands and the Entomological Society Krefeld in Germany, revealed.

The insect population dropped by more than 75 percent during the duration of the study, which was published in the peer-reviewed journal PLOS One. According to the report, climate change, loss of insect habitats and possible pesticide use is behind the decreased numbers. This discovery is notable to scientists because it views flying insects as a whole group.

“This study lumps all flying insects together,” research teaching fellow in entomology at Sydney University’s School of Life and Environmental Studies, Tanya Latty, said to CNN Thursday. “If you see these sort of dramatic declines in protected areas it makes me worry that this could be everywhere. There’s no reason to think this isn’t happening everywhere.”

The study set Malaise traps, a specialized net that captures insects, up in 63 German nature protection areas for the 27-year long study. Researchers measured the weight, also known as the biomass, of the insect catch from every Malaise trap to draw conclusions about the drop in insect numbers. According to the results, there is a 76 percent decline and mid-summer 82 percent decline in flying insect biomass in the 27 years researchers conducted the study.

The is worrisome because the study took place in protected areas, indicating the decline of flying insect populations in other areas, such as agricultural or urban areas, could be more prominent, Latty noted. Insects make up about 70 percent of all animal species and pollinate crops, contribute to pest control and are important to waste control, the researcher added.

The decline is independent from habitat type and cannot be explained by changes in weather, land use or habitat characteristics. “All these areas are protected and most of them are managed nature reserves,” a co-author of the study from Radboud University, Casper Hallmann, said. “Yet, this dramatic decline has occurred.”

Hallmann also said he was “very surprised” by the results. Researchers said in order to try and neutralize the issue, there should be less pesticide usage and there should be an extension of protected nature reserves. Otherwise, the effects on ecosystems could be dangerous — since many are dependent on insects for food as pollinators.

“The flying insect community as a whole has been decimated over the last few decades,” the study reads. “Loss of insect diversity and abundance is expected to provoke cascading effects on food webs and to jeopardize ecosystem services.”