Ohio’s Natural Enemies: Mantids

Order Mantodea, Family: Mantidae
ENT-67
Agriculture and Natural Resources
Date: 
01/14/2016
Mary Gardiner, Department of Entomology
Mary Griffith, Ohio State University Extension

How can one not be captivated watching a mantid stalk its prey? These charismatic garden predators are often called praying mantids because most species are sit-and-wait hunters that hold their front legs together as if in prayer while they survey their surroundings for a potential meal. Mantids have large eyes and are able to rotate their head to effectively monitor their surroundings for both prey and their own potential predators. When an unsuspecting insect does come within their reach, the mantid will use its raptorial front legs to grasp it. These legs are modified for this purpose, with spines that line the femur and tibia. Once they have captured a suitable prey, mantids consume their meal with strong chewing mandibles. 

Mantids can be found nearly anywhere in home landscapes including on trees, shrubs and garden annual and perennials as they are extreme generalists that will feed on just about anything they can catch. Their prey can include both pests and other beneficial arthropods such as bees and spiders. Although they are a large predatory insect, mantids do not bite humans.

Identification

One has to be looking closely at garden vegetation to notice a mantid. Although they are large insects (2 to 4½ inches) they often are well camouflaged to their surroundings, resembling leaves or sticks.

Mantids have a triangular head with large, compound eyes. They have long, slender bodies, and arms modified to tightly grasp prey. Adult mantids have wings.

Three species of mantids are found in Ohio. Both the European mantid (Mantis religiosa) and Chinese mantid (Tenodera sinensis) were introduced into the United States in the late 1800s and are now common in Ohio. The Carolina mantid (Stagmomantis carolina) is native to the United States and found from New York south to Florida and west to Utah, Arizona and Texas. Color is not a good character to distinguish species, as both green and brown color forms can be found for all three Ohio species. Mantids have a triangular head with large, compound eyes. They have long, slender bodies, and arms modified to tightly grasp prey. Adult mantids have wings.

 
European mantid
(Mantis religiosa)
Chinese mantid
(Tenodera sinensis)
Carolina mantid
(Stagmomantis carolina)

Photo courtesy of Joyce Gross.

Photo courtesy of Betsy Betros.

Photo courtesy of MaLisa Spring.
Adult size: 2¾ inches (7 cm) in length Adult size: 4½ inches (11.5 cm) in length Adult size: 2–2½ inches (5–6.5 cm) in length
Key character: Bull’s eye spot pattern located on the inside of the foreleg Key character: A green lateral strip is present along the edge of front wings Key character: Males and females have a dark spot on the forewing. In females, the abdomen is widened laterally and the wings only cover ¾ of the abdomen length.

Life Cycle

Female mantids have a bad reputation as man eaters. Females are known to kill and consume males after or during mating, although this mating behavior is not often observed in nature and may be exaggerated. It may be advantageous for the female to consume her mate to gain a necessary energy boost before laying eggs. Females are able to produce more eggs after this large meal and the males die soon after mating regardless. 

After mating, female mantids deposit their eggs in a mass of foam that hardens into an egg case, called an ootheca, that can contain up to 400 eggs. Mantids survive the winter as eggs in ootheca and hatch in the spring, emerging as wingless nymphs. Mantids develop via gradual metamorphosis meaning that they hatch from eggs into nymphs, or an immature stage, which closely resemble the adult stage of the insect. These nymphs lack wings and will molt several times to become a reproductive adult without going through a pupal stage. Mantids complete one generation per year, so watch for nymphs in spring to early summer and adults in mid-summer to fall. 

Adult male mantids are winged and can fly long distances. Females of species found in Ohio also have wings but often do not fly or fly infrequently. In Ohio, one generation of mantids develops each season.

Releasing Mantids for Biological Control

Mantid egg cases are marketed as a natural method of pest control and can be purchased for release in the garden. It is important to note that mantids are extreme generalists, and while they may feed on pests such as aphids, they will also feed on benign or even beneficial insects. Therefore, releasing these into your garden may not necessarily improve pest suppression. However, releasing mantids will not do any harm to the garden, and observing mantids can be a great way to introduce young people to entomology.

 

With fall colors comes the next generation of mantids. A female deposited her ootheca on this oak branch; it will hatch the following spring.
Photo courtesy of Dan Davison.

Inspect your plants closely for mantid nymphs. These wingless hunters camouflage well with garden vegetation.
Photo courtesy of MaLisa Spring.

 

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