18-8-2015 MONTE CORONA, VALENCIA - EUROPEAN MANTIS (MALE) (Mantis religiosa)

The European mantis (Mantis religiosa) is a large hemimetabolic insect in the family of the Mantidae ('mantids'), which is the largest family of the order Mantodea (mantises). Their common name praying mantis is derived from the distinctive posture of the first pair of legs that can be observed in animals in repose. It resembles a praying attitude. Both males and females have elongated bodies with two pairs of wings. The most striking features that all Mantodea share are a very mobile, triangular head with large compound eyes and their first pair of legs (the 'raptorial legs'), which is highly modified for the efficient capture and restraint of fast-moving or flying prey.

In Germany, M. religiosa is listed as Gefährdet [endangered] on the German Red List on the basis of an assessment from 1998. It is not supposed to be caught or held as a pet. At a global level, it is assessed by the IUCN as least concern.

Though females of M. religiosa are usually larger and heavier than males (7–9 cm versus 6–7 cm), the antennae and the eyes of male animals outsize those of the females. Along with the forward-directed, compound eyes, simple eyes also are found on the head. These three dorsal ocelli are also more pronounced in males than in females.

Males are often found to be more active and agile, whereas females are physically more powerful. Adult females are generally too large and heavy for their wings to enable a take-off.

Mantids show strong deimatic display from very early life stages on. This behavior can be observed throughout different groups of animals and is used to scare or startle potential predators to give the attacked animals a chance to escape. The deimatic display in M. religiosa involves wing spreading and bending of the raptorial legs to reveal two matched black eyespots with a yellow or white center at the base of the coxae (legs). It makes the animal appear much larger and more of a threat to the attacker. The black eyespots are also a distinct feature for species discrimination of the European mantis. Another unique feature of M. religiosa is its midline metathoracic ear (see Ultrasound avoidance). This “tympanal auditory organ” is an unpaired structure found on the ventral side of the animal on the metathorax between the third pair of legs. Unlike other sound-processing organs found among different groups of insects, the metathoracic ear has a high sensitivity across high and low frequencies and even ultrasound. Therefore, the authors call it a ‘true ear’.

The great variation in the coloration of M. religiosa from different shades of yellow, brown, green, and sometimes black has been the cause of numerous hypotheses and studies for over 100 years. However, no generally accepted answer about reason, benefit, or mechanism of the coloration or the change of coloration has been found.

Di Cesnola observed in 1904 that green mantids were found on fresh green grass, whereas brown individuals seemed to prefer brown grass burned by the sun. When forced to change the location as to no longer match their coloration, almost all the ‘not matching’ animals were killed by predators such as birds. This indicates a camouflaging purpose of the coloration.

Przibram also observed in 1907 that a change in temperature can trigger a change in coloration: animals that hatched in a cold environment turned green after moulting when heat and sunlight were provided. Without the change in temperature and only a change in the color of the background, no change in coloration occurred. This finding contradicts with Di Cesnola, who claims to have observed the animals within the same time and location (and therefore the same temperature).