In school there was a rumor that Chairman Mao convinced the population of China that everyone should participate in the Great Leap Forward and kill ten flies every day to help rid the country of a veritable plague of flies. One of our company representatives just returned from Beijing with photos aplenty. In all the pictures of the open-air markets, I spied nary a fly. Whaddaya know about it?
-- M. Faught, San Diego
After the revolution of 1949, the government of China launched campaigns against vermin to bring good hygiene to China's pestilent cities. In 1958 Mao decided birds were eating too much of the country's grain. All citizens were instructed to take to the streets, beating on pans to keep birds from roosting. Birds reportedly dropped out of the sky from exhaustion. Children were asked to bring two dead birds a day to school to prove their patriotism. Millions were killed, and China's bird population didn't recover for years. Nature, of course, gets the last laugh. It never occurred to anyone that once the birds were gone, the bugs would take over. A plague of caterpillars brought a pause in the war against birds.
Mao was notorious for these campaigns, which included battles against rats, mice, flies and dogs, as well as birds. I'm not sure that explains your friend's bugless photos, but with the anti-pest consciousness in Beijing, probably just out of camera range was a patriot with a fly swatter.