The Big Idea
Throughout your gardening, you will encounter a number of ‘bugs’. While your instinct may be to get rid of all of them, some insects are actually beneficial to your garden and it is a good idea to be able to discern between the two groups. Ladybugs are part of the helpful group as they eat several types of plant pests and can even be introduced on purpose as a biological pest control. Ladybugs are also a great teaching tool for studying food chains, insect anatomy, and natural defense mechanisms.
- Observe and describe major stages in the life cycle of plants and animals
- Classify animals into major groups according to their physical characteristics and behaviors
- Learn about ladybugs and how they are beneficial to the garden
About the Ladybug
The family name Coccinellidae includes all the beetles known as ‘ladybugs’. They also are commonly referred to as ‘lady beetle’ or ‘ladybird’, depending on where you are in the world. Ladybugs are actually not ‘bugs’ at all; they are insects meaning that they have 6 legs, antennae, and a 3 segmented body. Ladybugs come in different colors, typically in the range of dark red to orange to yellow and come with or without spots depending on age and species. They generally have black legs, head and antennae. Ladybugs are small, ranging in length from .04 to .4 of an inch. Worldwide, there are over 5,000 species with more than 400 in the United States alone.
Biological Pest Control
With only a few exceptions, most species of ladybugs are extremely beneficial to gardeners and farmers as a form of pest control. It is important to be able to identify the ladybug at all stages of life so it is not accidentally killed with pesticide. Ladybugs are a natural predator of mites, whiteflies, mealybugs, armored scale insects, scale insects, and, are, perhaps, best known for their use in the control of aphids. Ladybugs have ravenous appetites; a single ladybug may eat up to 5,000 aphids during its lifetime. There are several different methods of biological control, but generally speaking it refers to the use of natural predator-prey relationships to control pests. The classical method of biological control involves releasing ladybugs to control plant pests into an area where the beetle was not previously found. [Source]
Ladybug Life Cycle
The ladybug life cycle from egg to adult takes about 3-4 weeks, 4-6 in cool weather. The cycle begins when a cluster of 10 to 50 tiny, light yellow eggs are laid in a colony of aphids or other insect eaten by the ladybug. The eggs hatch in 3 to 5 days producing larva or juvenile forms. The larva looks like a long, spiny grub with 6 legs. They are usually black with some coloring but many brightly colored variations exist. Although it may look so, the larva is not poisonous. They are pretty ugly, but don’t kill them! The larvae go through 4 growth stages known as instars. After about 3 weeks, the larva pupates which is a transition stage. A week later, the pupa will hatch into an adult ladybug! If you would like to see more ladybugs in your garden, plant some of the following: cosmos, dandelion, dill, marigold, statice, mustard. Ladybugs do give off a foul smell when under stress and possess a color scheme that tends to scare away would-be predators. If a predator, typically stinkbugs or assassin bugs, don’t heed these warnings, ladybugs have been known to ‘play dead’. [Source]
Ladybugs in Pop-Culture
The ladybird beetle came to be named after farmers in the middle ages prayed to the Virgin Mary for their crops to be rescued from the pests devouring them. Soon after, the red and black spotted beetles showed up and they were called Lady Beetles after the Virgin Mary. There are countless sayings about ladybugs around the world. In many places the ladybug is considered good luck. If a ladybug lands on you, the spots should be counted and these can symbolize anything from marriage to crop success to how much money you will be receiving in the near future! Look up some ladybug sayings with your class and see which one you like the best!
Aphids, also known as plant lice, are among the most destructive insect pests of cultivated crops in temperate regions. Aphids are very small, varying in length from 1 to 10 millimeters. There are about 4,400 species of aphids spanning 10 families all belonging to the superfamily Aphidoidea. [Source]