We are mainly interested in the study of aphids (Hemiptera: Aphididae), insects that are important agricultural pests and have complex and fascinating life cycles. In spring and summer, aphid populations are solely made up of viviparous parthenogenetic females, i.e. mothers give birth to nymphs without an egg stage and without a father. During autumn, females sense that the days are getting shorter, heralding the arrival of winter, and this triggers a response within them, leading to the production of a single generation of sexual males and females. Sexual females, after mating, lay frost-resistant eggs that enter a programmed diapause. Thus, the overwintering egg will survive the harsh winter conditions and hatch in spring, giving rise to new viviparous parthenogenetic females.