Science Snippet: A Complex Relationship between Living Things

When the body of a honeybee is pierced by the fangs of a spider, its internal fluids, sort of equivalent to our blood, oozes out through the wound. The stuff attracts Desmometopa flies, small insects that hurry up to the dying bee to feed on the gooey fluid. They love the stuff. In South Africa there are “parachute” plants (Ceropegia sandersonii) that produce cone-shaped flowers that depend on Desmometopa flies to cross-pollinate the species. The flowers release an odor that is identical to that associated with wounded honeybees. Foraging flies find the odor irresistible and dive into the flower looking for a wounded bee. Downward-directed hairs inside the flower cause flies to be trapped in a pile of pollen at the bottom of the cone, where they wallow around and become covered in pollen. When the flower finally begins to droop, the flies pop out and carry the pollen to other parachute plants, thus ensuring cross-pollination between plants. The entire sequence, from spiders to wounded honeybees to Desmometopa to parachute plants, illustrates the complex relationships that can exist between living things. (The Economist, 2016, Oct. 8 issue; Heiduk et al, 2016, in Current Biology, Oct. Issue)

Article Comments