"Insect pests--Control." . . "Ladybugs--Ecology." . . . . . . "Juvenile works" . "Juvenile works"@en . . . . . . . . . . "A gardener upsets the natural balance in his garden by using poison and learns the value of another method of controlling pests." . . "A gardener upsets the natural balance in his garden by using poison and learns the value of another method of controlling pests."@en . . . "What about ladybugs?" . "What about ladybugs?"@en . . . . . . . . . "Garden pests--Biological control." . .