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

Praying Mantid Rearing

Natural History
Mantids belong to the insect order Mantodea and are closely related to the stick insects, grasshoppers, and cockroaches.  Their name comes from the Greek “mantis” which denotes one who sees the future (presumably because they have such large eyes and appear so “intelligent”).  There are more than 1800 species of mantids worldwide most of which are tropical.  Africa and Asia have the largest mantid diversity with 880 and 530 species respectively.  The United States and Canada have about 20 species all belonging to the family Mantidae.  All mantids are predators and usually lie in wait for their prey.  They have incomplete metamorphosis and overwinter in the egg stage; eggs are laid in a styrofoam-like ootheca or egg case attached to a twig or plant stem.  Each egg case can carry 200 or more eggs depending on the species.  On average a mantid's lifespan is 12 months.

Contrary to popular belief, females rarely eat their mates.  In fact females of some species produce a strong chemical pheromone to attract the males.  And in other species, males approach females very cautiously and often do a species-specific dance to determine that the female is indeed receptive.  For a good review of the “mate-eating” controversy in mantids see Alcock in References.  Another myth is that mantids are endangered and thus illegal to collect.  This is not true although there has been some concern that the imported species will displace our many beautiful native species.

Rearing
Mantid egg cases are often sold at local garden stores in the spring or can be purchased from various beneficial insect dealers (see Suppliers.)  Oothecae can also be collected from the wild but be sure not to collect one that has already hatched or has been parasitized (look for the tiny open holes where wasps or hatchling mantids may have already emerged.)  Carefully suspend the egg case from the top of a large jar using a thread or piece of wire.  Place a piece of paper towel in the bottom to help hold the humidity and mist the inside of the jar daily with water.  Mantids should hatch in early spring depending on the species, and temperature.  Some species will all hatch within hours, other species will hatch a few at a time for several days.  Once they hatch, place small sticks or twigs (preferably with dried leaves on them) in the jar for the nymphs to climb on.  Feed the hatchling mantids daily approximately 3-4 fruit flies per nymph and continue your daily misting of the jar. After a few days to a week you may want to separate the nymphs by putting 2-3 each in smaller containers.  Hatchling mantids have a tendency to eat each other and you can increase the numbers that survive to adulthood by separating them early. Initially a small container will make a suitable cage, but as the mantids grow, larger cages will be needed. Daily misting and live prey will provide moisture, but if your classroom is dry, you may need to provide additional moisture with a Petri dish filled with wet cotton or a wet sponge in each cage. High humidity is important for molting, but too much humidity can promote mold growth.

Hatchling mantids can be fed on "flightless" fruit flies (Drosophila sp.), aphids or other small insects such as newly hatched crickets (called pinheads). They do well if supplied with as much food as they can eat although they can survive a couple of days without food.   Always match the prey size to the size of the mantid’s grasping legs; they will simply run away from prey that are too large and can actually be harmed by large prey.  Adults will eat almost any living prey smaller than themselves.  Crickets and house flies are readily available and make excellent food items.  Flies are an invaluable food source for the intermediate stages. You may even want to supplement with moths captured at your porch light during the warmer months of the year.

Newly hatched mantids are small and fragile and need to be handled with a small soft paint brush.  You can also let them crawl on your hand or a small stick and then gently shake them off into another container if you need to clean their cage.  Large mantids may strike at your finger if you try to capture them and sometimes they hold on to your finger.  This can startle you, but don't be too alarmed as this usually doesn’t hurt and they don’t have venom.  They will let go once they realize that your finger isn't a cricket or other tasty meal.