MARCH
1988

 

 

 

By
Tom Turpin
 
Professor of
Entomology
Purdue University

 

 

 

 

 

03-18-88

LADYBUG, LADYBUG, FLY AWAY HOME

Some people know them as ladybugs.  They're also known as ladybird beetles or lady beetles, which are more appropriate names because these insects are beetles.  Lady beetles are bright orange or red in color and frequently have black spots. 

There are about 370 species of lady beetles in North America.  Most lady beetles are beneficial because they feed on a group of pest insects called aphids.  Aphids feed on plants – our garden plants, our crop plants, even our decorator plants.  Because of their appetites, the lady beetles can “eat up” an aphid problem.  A larvae of a lady beetle will consume 200-300 aphids before it becomes an adult.  Some lady beetles will lunch on over 500 aphids before laying eggs.  That's 15 to 20 aphids per day.

Farmers in the Middle Ages recognized that aphids could destroy their crops.  To help with the aphid problem, the ancient farmers sometimes prayed to the Virgin Mary, who is also know as Our Lady.  The aphid-eating beetles frequently saved the crop and gained the name “Our Lady” bug.

Ancient reverence for the insect and the season ending practice of burning crop stubble led to the familiar nursery rhyme about the lady bug.       

“Lady bug, lady bug, fly away home,
Your house is on fire, your children will burn!”

 The lady bug is admonished to fly away home to save her wingless youngsters before they perish in the fire.  The rhyme probably also reflects that lady bugs migrate during the fall season.  They seek protected places to spend the winter and, at the time, could be found far from “home.”

We still recognize the beneficial aspect of lady beetles – a process called biological control – in our gardens and crops.  Some gardeners purchase lady beetles by the quart for release.  It is important for homeowners considering such a practice to make sure that aphids, which are the food source for the beetles, are present at the time of release.  If food is not present, a modern version of the nursery rhyme will occur, and the beetles will “fly away, fly away” to some other home!

 

Writer: Tom Turpin
Editor: Steve Cain