According to legend, during the middle ages in Europe, the crops of the fields were attacked by swarms of insects, prompting the farmers to pray to the Virgin Mary for help. Soon after the prayers were lifted to the heavens, thousands of ladybugs descended and began to devour the insects that were destroying the crops. The farmers soon began referring to them as the "Beetles of Our Lady" which later evolved to lady beetles and eventually to the affectionate terms ladybirds and ladybugs.
The popular nursery rhyme may have origins in agriculture. It is said that farmers set their fields afire after the harvest to control insect pests and recited this rhyme to assure the ladybugs would survive.
"Ladybug (ladybird), Ladybug, Fly away home.
Your house is on fire and your children are gone."