A mating tangle of milkweed assassin bugs, with the larger female feeding on a sweat bee, paired with a male, while a third male jockeys for position. Austin, Texas, USA.
The sex lives of aphids during most of the year are unusually dull: female aphids are parthenogenetic, cloning themselves without mating at all. This strategy allows aphids to build their numbers very quickly. Sexual reproduction occurs at the end of the season, after winged forms are produced. Tucson, Arizona, USA.
Two male mosquitoes attempt to mate with a female. Laboratory culture at Rockefeller University.
