Japan is bracing for a swarm of stink bugs that can attack tree fruits, with an unusually large number of prefectures already issuing alerts. Of Japan’s 47 prefectures, 30 from west to east, including Tokyo, had issued stink bug alerts as of Friday, according to Ministry of Agriculture, Forestry and Fisheries data. The tally is in contrast to the previous 10 years, when the number of prefectures issuing stink bug alerts between January and May averaged around five but never topped 15. The number of insects has already been rising and is expected to surge further following the summer breeding s…