Praying Mantis Egg Sac, Case, Ootheca, Nest, Hatching

The egg-laying process begins in the adult female and ends with the first frost. The sac measures 1 inch (3cm) in diameter. The sac is about 1 inch (3 cm) in length, rectangular with rounded corners and tan-to-white. How are praying mantis egg capsules made? When do the egg sacs hatch and what do they look like? Find out how to care and maintain these fascinating insects eggs.

Information about Praying Mantis Egg Sac, Case, Ootheca

Praying mantis in your garden provides a safe and biological way to fight the summer’s flurry of insects. They are omnivorous and will eat any kind of food. However, they provide a natural pest control solution for mosquitoes, crickets moths, flies, and moths.

They go through a complicated life cycle that includes cannibalistic breeding, overwintering eggs and adulthood. You can find prayer mantis egg sacs across North America. However, in colder regions you may need to purchase them for your garden.

Start by looking up information about the praying mantis egg Sacs. When do mantis sacs hatch? When spring temperatures warm up, these predatory bugs begin to emerge out of their casings. This means that you should begin looking for cases in the late fall or early spring.

Females lay their eggs on stems, twigs, and walls. While the sacs may be difficult to spot, they will become more evident when trees lose their leaves. How many praying mantises lay eggs? Even though it is a small insect, the praying mantis can lay up to 300 eggs per sac. About one-fifth (or less) of these nymphs will live to adulthood. Therefore, it is vital to protect egg sacs in order to protect future generations of predators.

What does a Praying Mantis Egg Sac look like?

The eggs come surrounded by a foamy substance that hardens into their casing. The foam is called ootheca. If you are lucky enough to find one, you can observe the sac hatch in a glass or plastic container that has air holes. If the insect is immature, they will hatch within four to six week if brought indoors. However, they can be hatched immediately if found late in winter. The nymphs are miniature adults who will have voracious appetites and look just like adults. Let them go outside to get started in their work. The babies will die if you encourage hatching and release when the temperatures outside are below freezing.

How to Encourage Praying Mantis Gardening?

To encourage praying mantis, it is a simple thing to stop pesticide use. These insects are vulnerable to many kinds of chemical preparations. Prayer mantises are very susceptible to chemical preparations. If they don’t appear, then the population might have died. Egg sacs can be purchased and used to hatch new groups of insects in your garden. If you want to care for newly hatched baby nymphs, separate them into individual vials. They will either eat each other or be separated.

In each container, place a moist cottonball and give them fruit flies or other aphids. The task of keeping mantis babies in check until spring can be tedious so order your casings in the winter. Hatch them for spring release. You can also refrigerate eggs casings for a month in order to prevent hatching. Then, warm the sac slowly for a warm-season release.

Can you have Praying Mantis Eggs in your Garden?

You may have seen, or even beenfriended by praying mantises within your garden in this growing season. Although most adult mantises die in late fall and early Winter, there are likely some garden ornaments that they left behind.

All alien-looking mantises possess a pair feisty grasping legs which allow them catch their prey. They also have long, straight legs that allow them stomp and a triangular, twisting head that allows them to see around them. Praying mantise is the only insect capable of looking over its shoulder. They are able to wait motionless, and then use camouflage in order to capture unsuspecting insects. Some tropical species mimic orchid flowers, leaves and twigs. They can alter their color over time to match their surroundings.

The Chinese mantis and the Carolina one are the most common in Central Illinois. The Chinese mantis grows up to five feet longer than the Carolina one. They are typically tan to light brown, with some green and yellow stripes. Carolina mantises grow up to 2 1/2″ in length and can come in a variety colors (green, brown, and gray).

The Chinese mantis adult female will lay her egg case (known as an ootheca) on twigs. She only requires that the area holds her body weight, and is slightly vertical. This makes brick siding perfect.

After laying the egg, the ootheca rapidly hardens to allow for a winter sleep. Mothers will eventually die shortly after. These egg cases, which you will find in fall or winter, are light brown and approximately 1.5 inches in width. They look almost like foam insulation. Each foamy insulation case houses hundreds of mantis egg shells that are strong enough to withstand winter’s storms.

Carolina praying mantis teethecas are smaller and flatter than trilobites, and they are more common on flat vertical surfaces.

If the eggs must be removed from a wall they can be transferred to a shelter. Don’t leave an egg container on the ground. The eggs will be eaten by ants quickly.

Next spring will see the Nymphs emerge like an erupting from foam appendages. Then they will begin their journey to discover insects. This may include their brothers or sisters. The majority (or all) of the mantises born from an egg case will die due to starvation or cannibalism. They are territorial so by the end the summer there is usually only one remaining adult.

Is it possible for the Praying Mantis Sac to be relocated?

You can move the egg case to another location in your garden. Cut the stem with the eggcase attached, then move to another stem or crotch in an shrub about a foot off the ground. This will provide cover for the 100-200 tiny mantises hatching from the sac. To make sure the stem/case remains in place, you might use twine or wire to attach it. You should not place the egg sacs on the ground, as they will be eaten by ants.

Amazingly, there is over 2,400 different species of mantises worldwide. These are both in temperate and tropical environments. By blending into their surroundings, Mantises can camouflage themselves. Mantises have excellent vision and are good at eating insects. Although they don’t eat only certain insects, I love to have them in my yard!

Egg case (ootheca) of a Chinese mantis. Dendroica cerulean / Flickr (CC license)

How Long does it take for the Praying Mantis Eggs to Hatch?

Hatching needs at least 10-15 days of continuous warm temperatures (75-80degF, >50% RH ) to occur. This can take up to 6 week to complete. Once hatching is completed, the young mantids begin to look for food. The hatching process takes only a few hours once the egg sack has begun. For continued activity, Mantids will prefer temperatures over 60F.

How Many Praying Mantids Can You Find in One Egg Case?

Each egg case containing 50-200 eggs of the praying mantis is called an “ootheca” and it is collected from nature.

How Many Egg Cases Do I Need?

We recommend using three cases per 5,000 sq. 10 to 100 cases per acre. You need to space out every egg case in order to reduce the chance of mantid cannibalism.

How to Look After praying mantis eggs in your garden?

Did you ever find a brown, polystyrene mass on a shrub or tree in your garden? Many people find these odd-looking forms on their garden plants in autumn when the leaves start to turn brown. Many people believe it to be a cocoon. Although it is a sign insect activity, this is not a cocoon. This foamy structure can be identified as the egg case of a praying Mantis (an invertebrate family Manidae).

A praying mantis female deposits many eggs shortly after her mating. The eggs she lays may only be a handful or hundreds. The mother mantis covers her eggs with a thick substance that hardens rapidly to a consistency comparable to polystyrene. This egg case, also known as an “ootheca”, is also called a ootheca. After mating once, several oothecae may be produced by a single female mantis.

Praying mantises often lay their eggs in autumn or late summer. The young then develop within the ootheca throughout the winter. The egg case’s foamy structure protects offspring from cold and predators. Tiny mantis-nymphs hatch while their eggs are still in the eggcase.

Depending on their species and environmental factors, it may take between three and six months for the nymphs to emerge from the mouth of the ootheca. The young praying mantises are ready to hunt other small insects and will emerge from the protective foam cover in the spring or early the summer. They start to disperse immediately in search of food.

You might be tempted bring your ootheca inside if it is in fall or winter. Warning! The warmth of your house will feel like spring to the baby ants waiting to emerge. You don’t want to have 400 praying mantises crawling up your walls.

If you have collected an ootheca for the purpose of watching it hatch in the spring, place it in your refrigerator. For spring, you can keep the ootheca inside a terrarium. You shouldn’t keep young mantises in their cages. They are in hunting mode and will eat all of their siblings. Let them roam around your garden and help you with pest control.

It is possible to identify the particular species of mantid by its egg cases. allows you to identify the egg case that you find. This online community of naturalists shares photos of spiders, insects, and other related creatures. These are photos of some of the most common mantids found in North America.

The egg case at the top of this article is a Chinese-mantis (Tenodera sensis sinensis). This species is a native of China, Asia and North America. Chinese mantis eggs can be purchased from commercial biocontrol suppliers for gardeners and nurseries looking to use the mantis species to control pests.

Praying Mantis Egg Sac – Video

References & Further Reading

“Carolina Mantid Ootheca.” North Carolina Museum of Natural Sciences, Accessed 15 Sept. 2014.

Cranshaw, Whitney and Richard Redak. Bugs Rule! An Introduction to the World of Insects. Princeton University Press, 2013.

Eiseman, Charley and Noah Charney. Tracks & Sign of Insects and Other Invertebrates. Stackpole Books, 2010.

“Ootheca.” Amateur Entomologists’ Society, Accessed 15 Sept. 2014.

“Ootheca.” Museums Victoria. Accessed 15 Sept. 2014.

“Praying Mantid Care Sheet.” Amateur Entomologists’ Society, Accessed 15 Sept. 2014.

“Subspecies Tenodera sinensis – Chinese Mantis.” Accessed 15 Sept. 2014.


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