BLOWFLIES A dead body is a banquet to corpse-eating insects. Calliphora vicina, the blowfly seen hatching here from its pupa (above), is often the first to alight at the table of death, drawn by fresh flesh scented with acids and gases that signal the onset of decay. So sensitive are this insect’s eyes and antennae that it can spot a body when flying more than 115 feet above it. But breeding, not eating, is the adult blowfly’s aim: The female lays tiny eggs (below) in patches around orifices such as the nose, ears, and eyes and also on open, bloody wounds. The maggots into which they hatch burrow into flesh, exuding enzymes that can digest fats and collagen, a protein found in skin tendons and cartilage. Ugly though they may be, blowflies benefit humans by decomposing debris. They are also of serious interest to forensic scientists, who can estimate the time of death—and thus help solve crimes—by examining the insects that settle on a corpse. That’s because insects visit a body in discrete waves for months or years if a body is left unburied. For example, forensic entomologist Gail Anderson of Simon Fraser University in Burnaby British Columbia, helped solve a poaching case by examining fresh blowfly eggs laid on twin bear cubs that had been shot and gutted for their gallbladders, a prized ingredient in some Asian medicines. By watching the eggs until they hatched, she could pinpoint the time they had been laid—on an evening when two suspects had been seen near where the bears’ bodies had been dumped. Her evidence helped send the two men to jail. |
HONEYBEE Humans have been helping themselves to honey and beeswax for at least 3,000 years, when they first domesticated the bee. Apis mellifera—seen here above as it hatches from a honeycomb—provides other benefits: About one-third of the human diet is derived from bee-pollinated crops. Were bees to become extinct, we would most likely lose almonds, oranges, apples, blueberries, eggplants, tea, garlic, carrots, and onions, among many others. Humans have exploited bees for other reasons. Bee venom has long been known to soothe arthritis, probably because it contains melittin, a potent anti-inflammatory agent. Honey itself is active against bacteria. Microbiologist Rose Cooper at the University of Wales has found honey to be 10 times more effective than a sugar solution at killing antibiotic-resistant Staphylococcus aureas, a wound-infecting bacterium common in hospitals, perhaps because honey contains plant chemicals that inhibit microbial growth. |
