An adult cicada rests after shedding its nymphal skin, on the bark of an an oak tree early on May 5, 2021, on the University of Maryland campus in College Park, Maryland. Trillions of cicadas are about to emerge from 15 states in the U.S. East. Scientists say Brood X is one of the biggest for these bugs which come out only once every 17 years.
2021年5月5日清晨,馬里蘭州,在馬里蘭大學(xué)市分校校園里,一只脫落了若蟲皮膚的成年蟬在一棵橡樹上休息。美國東部15個(gè)州即將出現(xiàn)數(shù)以萬億計(jì)的蟬。科學(xué)家們說,孵卵X是這些蟲子中最大的一種,它們每17年才出現(xiàn)。