If you spend time in the garden, chances are you’ve encountered an aphid before. Actually, you likely discovered dozens, if not hundreds, since these insects are infamous for their ability to reproduce.
While not all aphids follow the rather unique and complicated reproductive path we’re about to describe, for most species living in regions that experience cold winters, it sounds something like this.
The aphids survive winter in the egg stage and emerge with the return of warmer weather. Surprisingly, all of the hatching eggs produce females. So, with no males in the population, the ladies employ a different reproductive strategy.
Throughout the summer, the aphids continue to build their all-female ranks through parthenogenesis (or asexual reproduction), producing only more females. If that were not unique enough, instead of laying eggs, like most other insects, the females produce living young, skipping the egg stage all together.
But that shortcut is not enough to account for how quickly aphid populations can expand. They take asexual reproduction to an even higher level.
Since the eggs inside a female aphid begin to develop immediately after ovulation, adult female aphids are filled with unborn female nymphs that already have developing eggs inside of them. This phenomenon is called “telescoping of generations”. In essence, the female nymphs are born already pregnant, allowing the population to boom.
As fall approaches, the change in temperature and daylength causes a dramatic change in the female aphid nation. Instead of producing only females, males will enter the population.
After mating with the males, the female aphids will lay eggs that will survive the winter and start their aphid sisterhood all over again in the spring.