Overview & Lesson Sequence

Focus on Standards & Assessment

Materials Needed, Preparation & Planning, Management Strategies

Background Info

Intro Activity
Why Study Predator - Prey interactions?

Activity 1
Observation of a predator-prey interaction

Activity 2
What makes a predator successful?

Research Project
Designing a predator - prey experiment

Optional Activity
Biological Control vs. Pesticides

Case Study
Rabbits in Australia

References

Glossary

Suppliers

Resource Sheets
-Plant Propogation
-Rearing Aphids
-Eyelash Brush
-Petri Dish Habitat
-Sampling Methods
-Observation Check Sheet
-Sample Rubric for Group Presentation
-One Gallon Cage
-Predators in the Environment Data Sheet
-Predation Inquiry
-Green lacewing Larval Mouthparts
-Chewing Mouthparts
-Hemipteran Mouthparts

Rearing
-Green lacewing
-Ladybird Beetle
-Big eyed Bug
-Praying Mantid
-Aphids
-Fruit Fly

Anatomy
-Green lacewing
-Ladybird Beetle
-Praying Mantid
-Big eyed Bug

Enforcers Home

CISEO Home

Ladybird Beetle Rearing

The Convergent Lady Beetle (Hypodamia convergens) is a native of North America and adults are about 4-7 mm long.  They have orange wing covers that typically have six small black spots on each wing cover. However, the number of spots can vary, and some adults have no spots on their wing covers. The section of the body behind the head is black with white margins and two converging white lines, hence the common name, “Convergent Lady Beetle” . Females lay clusters of 10-50 yellow eggs on plants infested with aphids. The larvae grow and molt through four stages and there are one or two generations each year depending on the weather.

The Sevenspotted Lady Beetle (Coccinella septempunctata) was introduced into North America from Europe. Adults are large (about 10mm), have red wing covers with seven black spots. Females lay clusters of 15 to 70 yellow eggs on plants that are infested with aphids. Adult beetles overwinter in small groups in hedges, or in leaf litter on the ground near the base of plants.

The larval stages of lady bird beetles are not as easily recognized as the adults, but are voracious predators of pest insects. The size and coloration of the larval stages vary among species, but generally the larvae are soft bodied and shaped like a miniature alligator. Newly hatched larvae are gray or black and less than 4 mm long. Later stage larvae can be gray, black, or blue with bright yellow or orange markings on the body.

Lady bird beetles are common in most agricultural and garden habitats. Their beneficial predatory behaviors should be recognized and their presence indicates that natural biological control is occurring. Lady bird beetle activity can be encouraged through the reduced use of insecticides or the use of selective insecticides. Also, the planting of a variety of crops or creating habitats for beneficial insects may provide lady beetle species with several types of prey and possible nectar and pollen sources.

Rearing
Ladybird beetles can be collected as larvae and adults from the wild during the spring and summer months.  A good place to look for them is on plants infested with aphids, such as Sowthistle or in your vegetable garden (provided you haven't been spraying insecticides!).  Adult beetles and the larvae of the Pink Spotted Lady Beetle can also be purchased from suppliers (see Suppliers).  Most purchased beetles (except the Pink Spotted Lady Beetle) are collected from overwintering sites and then held in a refrigerator until shipped to nurseries around the country.  For an account of how they are collected see Hubbell listed in the References.  Note that when beetles are purchased in the fall, they often will not feed since they are preparing for their migration and winter diapause.

Whether purchased or collected in the wild, adult beetles can be housed in a jar or aquarium with plenty of ventilation and a tight fitting lid.  It is best to provide them with plenty of their favorite prey (e.g. aphids), but it is often difficult to provide enough aphids to satisfy their voracious appetites.  As an alternative, you can provide them with moist cotton and cut grapes or raisins that have been soaked in water until swollen.  With the moisture and a sugar source, they will survive for several days in captivity, however, they will not usually lay eggs until they have acquired some protein in their diet.  You may also store the beetles in the refrigerator for several weeks as long as you take them out, warm them, and provide fresh water and grapes every few days.  In addition, some species will feed on frozen aphids or on an artificial diet (see Majerus in References).

Larvae can be housed similarly and fed live aphids or insect eggs (purchased), frozen aphids, or artificial diet.

Adults can be handled with a pair of soft forceps or with your fingers, especially if you have long fingernails.  Often they will produce a pungent yellow secretion when stressed.  Larvae should be handled with a small, soft brush.