Mantodea (Mantids)

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Mantodea

(Mantids)

Class Insecta

Order Mantodea

Number of families 15

Evolution and systematics

Praying mantids evolved during the early Cenozoic era (65 million years ago) from the cockroaches. Although it is widely accepted that mantids are related most closely to the cockroaches, the higher classification of mantids continues to be debated. Some entomologists contend that mantids should be grouped with the cockroaches in a single order, Dictyoptera, whereas others believe that the two groups should be placed in their own orders, Mantodea, the praying mantids, and Blattodea, the cockroaches. The latter approach is followed in this chapter.

The order Mantodea comprises 15 families that contain 434 genera and 2,300 species. The neotropical families Chaeteessidae and Mantoididae and the Old World family Metallyticidae all contain a single genus each and are considered by experts to be the most primitive mantid families. The Amorphoscelidae and Eremiaphilidae are two small families diversified throughout Africa and Asia. These five families generally have a thorax (pronotum) that is more or less square, as contrasted with the remaining families, whose pronotums are relatively elongated. The vast majority of mantids are grouped into these remaining families: Mantidae, Hymenopodidae, Acanthopidae, Liturgusidae, Tarachodidae, Thespidae, Iridopterygidae, Toxoderidae, Sibyllidae, and Empusidae. Many

of the latter families were once subfamilies grouped under the Mantidae, but they have been elevated to family status.

Physical characteristics

Mantids generally are large, ranging in size from just under 0.4 in (1 cm) to more than 6.7 in (17 cm). Females usually are larger than males, sometimes twice their size. Their coloration depends primarily on where they live. Mantids that are found in savannas and meadows are straw-colored or light green. Those that inhabit leaf litter tend to be dark brown. Mantids that frequent flowers in search of prey typically are yellow, white, pink or light green.

All mantids are perhaps best known for their raptorial forelegs, which they use to capture live prey. Two rows of spines on the femur and an opposing row on the tibia (except in the family Amorphoscelidae, which has only a single femoral spine) enable them to impale prey. The number and arrangement of foreleg spines are important characteristics used by entomologists to classify mantids.

Flexible neck muscles allow mantids to turn their heads a full 180 degrees. The head is triangular in shape, except in some species, such as Gongylus gongylodes, that have an elongated vertex between the eyes. All mantids have two large, compound eyes and three small, simple eyes (ocelli). The antennae of most mantids are narrow and long and have

many segments, but some species have antennae that are feathery, as in male G. gongylodes.

The thorax (pronotum) is longer than it is wide in most species and sometimes is expanded laterally, as in the subfamilies Deroplatyinae and Choeradodinae. Mantids generally have two pairs of wings, the forewings (tegmina) and the hind wings, but wing structure varies widely among mantid families from those having no wings (apterous) to those having two pairs of wings that are fully developed. The abdomen has 10 segments and terminates with the genitalia and a pair of multisegmented cerci.

Distribution

The majority of species are tropical and are concentrated in the rainforests of South America, Africa, and Southeast Asia. Mantid diversity decreases in temperate regions, and they are not found in boreal and tundra climates. Although most of these insects are limited in their distributions, a few species are widespread and found on more than one continent, such as the Chinese mantid, Tenodera aridifolia sinensis, and the European mantid, Mantis religiosa. These two species have become widespread since humans began transporting nursery stock with attached egg cases (ootheca) around the world.

Habitat

Mantids are entirely terrestrial and inhabit rainforests, dry forests, primary and secondary forests, grasslands, and deserts. In temperate regions, mantids complete one entire life cycle per season, whereas in the tropics, mantids can have overlapping generations.

Behavior

Numerous interesting types of behavior have been studied among the praying mantids. They are known to groom themselves frequently. Using their forelegs, they wipe their eyes and heads and then systematically clean their forelegs with their mouths. They do the same with their antennae and middle and hind legs.

Mantids have evolved certain means of defending themselves against potential predators. When faced with danger, most species attempt to run or fly away. If this does not deter the predator, the mantid may react with a startle display that includes thrusting out the forelegs, flashing out the wings, and opening the mouth. In many species the undersides of the forelegs and wings are brightly colored, so the sudden flash of these colors produces a startling effect. If these kinds of defensive behavior fail, mantids may resort to playing dead (thanatosis) or biting and pinching.

Feeding ecology and diet

Ecologically, mantids are considered top arthropod predators in the food chain. They are generalist feeders and can catch and consume arthropods primarily of equal or smaller size. Rarely, large mantids have been known to ensnare small mice, lizards, frogs, and birds. Hatchling mantids typically feed on aphids and other insects of similar size, whereas adults prey upon larger insects, including butterflies. Most mantids are opportunistic feeders and perch motionless, awaiting suitable prey; a few species actually chase down prey. Known for being cannibals, mantids consume each other if the opportunity arises. Large eyes and extraordinarily quick foreleg strikes enable these insects visually hunting predators to capture prey in 1/20 of a second.

Reproductive biology

Perhaps the best-known myth that pertains to mantids is that females always decapitate males during copulation. Although this does occur occasionally, it is not commonplace. It is true, however, that if the female cannibalizes the male during copulation, he continues to mate with her even without his head. Once the male has inserted the sperm packet into the female's abdomen, she uses his sperm to fertilize her eggs. One to several egg cases containing 10–200 eggs (depending on species) are laid over the next several weeks. Eggs are encased in a frothy liquid that hardens and protects the eggs until they hatch.

Conservation status

Although there are perhaps a few rare extant mantid species (one species is known only from a few islands in the Galapagos archipelago), there are little data regarding the overall status of mantid populations. Global warming, habitat destruction, and misuse of pesticides, however, have a detrimental effect on species. One species is listed in the IUCN Red Book: Apteromantis aptera, found in localized areas of Spain and categorized as Lower Risk/Near Threatened.

Significance to humans

Humans have both feared and revered praying mantids for more than a thousand years. Mantids have been frequent subjects of art and literature. Their prayerful pose was once thought to help travelers find a way home. The Chinese used mantids in fighting games. Indeed, there is a style of kung fu that mimics the movements of mantids.

In more practical terms, the Chinese mantid, T. a. sinensis, has been used extensively as a means of biological control for plant pests. People purchase egg cases in the winter and place them in their gardens for hatching the following spring, the goal being to have mantids consume plant pests, such as aphids. Most people do not realize, however, that mantids are generalist predators; they consume plant pests in addition to any arthropod, including other mantids and beneficial insects.

Praying mantids have become common in the pet trade. Such species as Deroplatys lobata, Hymenopus coronatus, and T.a. sinensis are especially popular among hobbyists.

Species accounts

List of Species

Wandering violin mantid
Orchid mantid
Liturgusa charpentieri
Choeradodis rhomboidea
Dead-leaf mantid
European mantid
Chinese mantid
Boxer mantid

Wandering violin mantid

Gongylus gongylodes

family

Empusidae

taxonomy

Gongylus gongylodes Linnaeus, 1758, India.

other common names

English: Rose mantid.

physical characteristics

Varies from light to dark brown in color. The head has a conical extension at the vertex. The anterior portion of the extremely thin thorax is expanded laterally in a diamond shape. All legs have leaflike extensions. Males are 2.8–3.1 in (7–8 cm) long; females, 3.1–3.5 in (8–9 cm). Male antennae are feathery, whereas female antennae are threadlike.

distribution

Southern India, Sri Lanka, Thailand, and eastern Java.

habitat

Primary and secondary rainforests.

behavior

Physical characteristics allow them to blend in well in leaf litter and shrubbery.

feeding ecology and diet

Preys chiefly upon flying insects that it can catch.

reproductive biology

Oothecae containing 50–100 eggs are deposited on woody stems and hatch after several weeks.

conservation status

Not listed by the IUCN, but is probably threatened by habitat destruction due to overpopulation.

significance to humans

None known.

Orchid mantid

Hymenopus coronatus

family

Hymenopodidae

taxonomy

Hymenopus coronatus Olivier, 1792, Java.

other common names

English: Flower mantid.

physical characteristics

Adults are white with pink patches on the head, the anterior and middle portions of the forewings, and the legs. Females are twice as long as males, averaging 2 in (5 cm) and 1 in (2.5 cm), respectively). The eyes are conical and rise above the dorsal edge of the head. Legs have leaflike projections.

distribution

Southeast Asia.

habitat

Primary and secondary rainforests.

behavior

Commonly found in or near flowers, awaiting prey. During courtship males tap their antennae and forelegs against the wings of the females, presumably to signal a willingness to mate.

feeding ecology and diet

Predators of small arthropods.

reproductive biology

Long, narrow oothecae (2 in, or 5 cm) are laid on stems and branches of plants and shrubs. The first-stage larvae have red bodies and black heads, resembling ants. This ant mimicry is thought to protect them from predators.

conservation status

Not threatened.

significance to humans

This is a popular species among hobbyists.

No common name

Liturgusa charpentieri

family

Liturgusidae

taxonomy

Liturgusa charpentieri Giglio-Tos, 1927, Brazil.

other common names

None known.

physical characteristics

Mottled, lichen-colored elytra and legs camouflage this mantid well against tree trunks. The body is dorsoventrally flattened. The head is held with the mouthparts facing forward (prognathous). Adult females are 2.5 in (6 cm) long; males, 1.6 in (4 cm).

distribution

Yucatán peninsula south through the Amazon basin.

habitat

Primary and secondary rainforests.

behavior

Often found facing upside down on large tree trunks. When startled, they scamper around to the opposite side of the tree very quickly and then remain motionless to avoid detection.

feeding ecology and diet

Opportunistic carnivores of smaller arthropods.

reproductive biology

Females attach oothecae inside bark fissures or under leaves. The exterior shell of the egg case is amber colored and opaque, allowing the eggs to be seen inside the case.

conservation status

Not threatened.

significance to humans

None known.

No common name

Choeradodis rhomboidea

family

Mantidae

taxonomy

Choeradodis rhomboidea Stoll, 1813, Surinam.

other common names

None known.

physical characteristics

Their uniformly leafy green color makes them difficult to find in the forest. The pronotum, or shield, is laterally flattened and leaflike. Males and females attain lengths up to 3 in (7.5 cm)

distribution

Amazon basin of South America.

habitat

Primary and secondary rainforests.

behavior

Perch on leaves and remain motionless, completely blending into their verdant environment as they await passing prey.

feeding ecology and diet

Opportunistic feeders of smaller arthropods.

reproductive biology

After mating, females deposit 50–100 eggs inside an ootheca attached to the underside of a leaf or branch.

conservation status

Not threatened.

significance to humans

None known.

Dead-leaf mantid

Deroplatys lobata

family

Mantidae

taxonomy

Deroplatys lobata Guérin-Méneville, 1838, type locality not known.

other common names

None known.

physical characteristics

These mantids are extraordinary mimics of dry, dead leaves. Their coloration is mottled light gray to dark brown. The leaflike pronotum is expanded laterally. Middle and hind legs have leaflike expansions, further adding to their camouflage. Adult males, at 2.5 in (6 cm) are approximately two-thirds the length of adult females, at 2.8 (7 cm).

distribution

Southeast Asia.

habitat

Primary and secondary rainforests.

behavior

Dwells in leaf litter and shrubs. When threatened, these insects assume a startle posture by exposing their brightly colored forelegs as well as eyespots on the ventral sides of their forewings.

feeding ecology and diet

Carnivores of small arthropods.

reproductive biology

Females lay oothecae on twigs. Hatchling mantids (50–100) emerge 30–50 days later.

conservation status

Widespread, but habitat destruction threatens them. Not listed by the IUCN.

significance to humans

None known.

European mantid

Mantis religiosa

family

Mantidae

taxonomy

Mantis religiosa Linnaeus, 1758, Africa.

other common names

None known.

physical characteristics

Varies from light green to brown in coloration, blending in with surrounding vegetation. Has a distinguishing bull's-eye spot on the inner forelegs. Adult males vary in length from 2–2.5 in (5–6 cm); females, from 2.5–3.2 in (6–8 cm).

distribution

Widely distributed in southern Europe, Africa, temperate Asia, Australia, the northeastern United States, and Canada.

habitat

Open fields and meadows.

behavior

These mantids fly well; then fly toward bright lights at night.

feeding ecology and diet

Predators of small arthropods.

reproductive biology

Egg cases (50–100 eggs each) are laid in autumn, primarily on low grass stems; they also can be found on rocks or buildings. Larvae hatch in spring.

conservation status

Very widespread. Introductions into the United States have expanded its range. Not listed by the IUCN.

significance to humans

None known.

Chinese mantid

Tenodera aridifolia sinensis

family

Mantidae

taxonomy

Tenodera aridifolia sinensis Saussure, 1871, type locality not known.

other common names

None known.

physical characteristics

One of the largest mantids, females can attain lengths of 4 in (10 cm) or more. Chinese mantids are marbled green, brown, and gray, with a distinct pale green border on the anterior edge of the first pair of wings.

distribution

Found in temperate eastern Asia, the eastern United States, and California. Deliberately introduced to the United States in 1896.

habitat

Meadows and open fields.

behavior

Seen on herbaceous plants and woody shrubs. Sometimes found adjacent to flowers, awaiting potential prey.

feeding ecology and diet

Carnivores. Devours any arthropod it can ensnare.

reproductive biology

Females produce 100–200 eggs inside a spongy ootheca and attach it almost anywhere, including leaves, branches, buildings, and vehicles. Eggs overwinter in the ootheca, and the larvae hatch in spring.

conservation status

Widespread in its range. Global warming eventually may restrict this species to a more limited temperate range. Not listed by the IUCN.

significance to humans

Often kept as pets.

Boxer mantid

Theopropus elegans

family

Mantidae

taxonomy

Theopropus elegans Westwood, 1832, type locality not known.

other common names

English: Banded mantid.

physical characteristics

Hatchling larvae are red-and-black ant mimics until their first molt, after which they become green and white. Adult females are 1.6–2 in (4–5 cm) long, and males are 0.8–1.2 in (2–3 cm). Both sexes are spotted green and white with a large white transverse strip on the forewings. Hind wings are bright orange.

distribution

Southeast Asia.

habitat

Primary and secondary rainforests.

behavior

Hides among flowers to catch prey. When encountering another mantid of the same species, they thrust out their forelegs in an apparent boxing motion—hence their common name.