We saved the scariest and most disturbing bug news to share today, in honor of all the little vampires and ghouls out there. This strange but true news comes from Discover Magazine's blog, in an article here. Apparently, scientists have discovered a new tendency in bugs: they crave blood! For mosquitos and bed bugs, this is not unusual. But these are insects that generally have been attracted by sweet substances, and are now looking for salt.
According to the article, research teams studying insects in Peru became puzzled when they were attacked by swarms of tiny bees. The bees were trying to get a taste of their sweat! Animals, and apparently even insects, need salt to maintain water balance in their cells.
Armed with new evidence and theories to test, the scientists baited ants on the Peruvian forest floor with vials of both sugary and salty water, then counted the ant species they baited. Ants living close to the ocean, and thereby near a source of salt, preferred the sugar. Inland ants preferred salt. Further, the scientists found the salt cravings were only seen in vegetarian ants, as carnivorous ants got enough salt from the bodies of their prey. Their report was published in the Proceedings of the National Academy of Sciences.
Which brings us to vampire moths. In another study, entomologists researched a population of fruit-feeding moths (Calyptra thalictri) which evolved the habit of feeding on blood. These moths, native to Russia, use their long, sharp tongues to pierce human skin now instead of peaches and pears. They have been observed sucking blood from the scientists' hands for more than 20 minutes at a time. According to the Discover article, only male moths engage in blood-feeding. The scientists suspect they are offering the salt from the blood as a gift to females during copulation. Happy Hallowe'en!