Article Summary:
The insect population, including cabbage moths, corn borers, and dragonflies, in East Asia, has been drastically declining over the past two decades, according to a study from the Chinese Academy of Agricultural Sciences in Beijing. The team tracked the migration patterns of almost 100 species of insects, with overall insect levels in the migration corridor between China, the Korean Peninsula, and Japan decreasing by nearly 8%, and predator insect levels going down almost 20%. The reduction in plant-eating insects and their predator counterparts causes a ripple effect that weakens the whole food web, ultimately leading to an ecosystem’s collapse.
The lack of predators such as dragonflies, beetles, and other insects that consume plant-eating insects like aphids and caterpillars allows the latter to feed on crops like soybeans, corn, and cotton. The consequences can affect food production and economies. The scientists used radar and light traps to track insects flying over Beihuang Island in Bohai Bay between China and the Korean Peninsula from 2003 through 2020. The study aligns with other research on alarming rates of insect disappearance, such as beetles in Puerto Rico, flies in Germany’s swamps, and butterflies on the American prairie.
The vanishing of insects poses a problem as they play a critical role in ecosystems by pollinating plants and controlling pests that harm essential crops. A massive die-off could throw ecosystems out of balance, cause food chains to collapse, and lead to the extinction of some species and an overabundance of others. The reduction of predators from the top levels of the food chain allows lower levels, such as aphids and caterpillars, to overindulge in their food sources, throwing plants out of balance.
Roads, farmland, and invasive species are encroaching on insects’ habitats, and pesticides are polluting what remains. Climate change has led to irregular weather and seasonal patterns that benefit some insects while causing harm to others. Restoration projects that include reintroducing predator species can help reverse the die-off. Scientists can also use the research to develop new methods of pest control for food crops that reduce the need for pesticides by deploying predator insects instead. “Insects provide important services to humanity,” said Kris Wyckhuys, a co-author of the study.