Scientists from the United States and Mexico have found a noticeable decrease in the number of insects in the rainforest in the El Yunque National Reserve (Puerto Rico). In addition, many insectivores have disappeared. According to experts, this reflects a global trend that threatens food security around the world, as arthropods are needed to pollinate many crops. This is reported by Science Alert.
In 2014, an international team of researchers calculated that over the past 35 years, the number of invertebrates such as bees and beetles worldwide has fallen by 45 percent. Europe was hit hardest, but insects are now also disappearing on the American continents. In 2017, another team examined the fall in flying insects in Germany, suggesting pesticides and habitat destruction were the cause.
Scientists have been counting invertebrates in the 70s of the last century, as well as in 2013. It turned out that the biomass of arthropods over 40 years has decreased significantly, reaching one fourth or one eighth of the previous number. From January 1977 to January 2013, the number of caught insects decreased 60 times.
The number of insectivorous anole lizards has decreased by 30 percent, and some species have disappeared from the forest. The number of frogs and birds has decreased. For example, the capture of Arthropod-eating Puerto Rican Todi has been reduced by 90 percent.
Experts attribute this to global warming. Over 40 years, the average temperature in tropical forests has increased by 2.2 degrees Celsius. This disrupts the breeding cycle of insects that cannot lay eggs, and disrupts food chains, as arthropods provide food for many other animals.
