Key to Australian Freshwater and Terrestrial Invertebrates
Phylum Arthropoda
Subphylum Hexapoda
Class Insecta
Order Mantodea
Common names: mantids, preying mantis
Overview
Mantodea, or praying mantids, are a small group of large predatory insects, commonly recognised by their characteristic posture � they hold their spiny (raptorial) forelegs together as if praying. Mantids typically have a slender, elongate body, ranging in length from 10�120 mm; a highly movable, triangular-shaped head with large compound eyes, short to medium length antennae and mandibulate (chewing) mouthparts; and two pairs of wings, the leathery forewings covering the membranous hindwings when at rest. Several species (particularly the female of a species) are wingless (apterous) or have reduced wings (brachypterous). Mantids typically display complex courtship, territoriality and defensive behaviours.
Distribution and diversity
Praying mantids are found across Australia in a wide variety of habitats from the arid interior to the wet tropics, with the greatest diversity found in the northern regions of the continent. The group reaches its greatest diversity in the tropics and worldwide there are about 2,300 described species in 430 genera. The Australian fauna comprises three families, 38 genera and 105 described species, about 65% of which are endemic. It has been estimated that at least an additional 30 to 40 species await description.
Life cycle
Sperm transfer from male to female in praying mantids is direct, and notoriously, in some species the female may attack and eat the male during or after mating. Depending on the species, females lay 10�400 eggs. The eggs are encased in a foamy substance that hardens into an egg case (ootheca), usually found attached to grass stems, branches, tree trunks, logs, fences and house walls or in the ground beneath a rock or wood. Some females guard the ootheca until the eggs hatch while others simply lay their eggs and leave. On hatching nymphs resemble small adults, but lack wings; they develop through a series of nymphal instars before adulthood. In cooler areas nymphs may take up to one year to reach maturity. In warmer regions there may be up to two generations per year.
Feeding
Adult and nymphal praying mantids are carnivorous, eating a wide variety of arthropods, mostly insects. Large species have even been recorded feeding on frogs, small lizards and small fledgling birds. Mantids wait in ambush on vegetation or slowly stalk their prey, which they seize and hold with their powerful raptorial forelegs.
Ecology
Mantids occur in most terrestrial habitats and can be found in trees and shrubs, grass or on the ground. Adults tend to be widely dispersed and solitary. They are often well camouflaged, blending in with the microhabitats where they hunt and live. In suburban gardens they can often be seen on vegetation and on the sides of buildings. Many are attracted to lights at night and hunt other insects that gather around light sources. Preying mantids are important predators of insects, including herbivorous pests, and cultural practices are often employed to encourage their presence in gardens, orchards and crops.
