Female aphids are able to clone themselves without sex--producing up to 100 copies of herself that carry all of her DNA with them, instead of being muddled by some other pesky male's genes. Her offspring live up to 40 days and produce their own set of clones, so one single aphid can end up producing many billion clones by the end of the summer.
In colder climates, these aphids start producing male clones (which are identical to the mother except they lack a sex chromosome). The aphids do, however, take a lover every year or so to cleanse their bacterial palette by picking up a male's cohort of bacteria in the form of a sexually transmitted infection.
These bacteria are actually helpful for the aphid: They can protect them against parasites or enable them to eat different kinds of plants and withstand higher temperatures. The mothers can then pass these useful sexually transmitted diseases down to their clonal offspring.