Praying Mantis
Introduced Species Beneficial State Insect of Connecticut
An unusual pet with strange cannibalistic mating habits.
The Praying Mantis (Mantis religiosa) is native to Europe, but it was introduced into North America at the end of the nineteenth century. It can be found in the wild in most parts of eastern America, right up to Ontario. Mantis religiosa is the official state insect of Connecticut, where it is a protected species.
Pest Control
All of the world’s two thousand or so mantids are voracious predators, with each of the twenty native American species specialising in insects of different sizes – from aphids up to grasshoppers and beetles (and occasionally small birds etc.!).. This makes them very good agents of ‘natural pest control’, and many are released annually in America to perform this task. These native American species, along with the European Mantis (Mantis religiosa) and the Chinese Mantis (Tenodera aridifolia sinensis) are all considered to be beneficial insects.
Mantids as Pets
Many people keep mantids as pets, but in America it is only legal to keep the native species or the introduced ‘European’ and ‘Chinese’ ones. The concern here is that any 'exotic' escaped pet mantids might upset the ‘balance of nature’ and effectively wipe out some of the native species (in much the same way as the introduced Harlequin Ladybird is now doing with native ‘Ladybugs’). All mantids look a bit ‘alien’ and their movements are almost mechanical – they can be fascinating to watch (look at this YouTube Video).
Mating Habits
It is rather dangerous to be a male praying mantis when it comes to mating – the females have a nasty habit of eating their mates when copulation is over! It is thought that this strange behaviour might have evolved to favour cautious males, since these would be expected to produce more offspring carrying their genes. If you are not sufficiently careful then you die after mating just once, but if you are careful you can go on to mate several times. (See: Sex and Genetics). But this is not the only danger that amorous males face – in order to find a mate they need to fly around at night, just when hungry bats are looking for a meal.
Senses
At night female mantids give of an attractive scent (pheromone) when they are ready to mate. The males can detect this chemical (with their antennae) over long distances, and fly off to search out the females. When they are in the air there is a serious threat from bats, but the male mantids can ‘hear’ the bats’ echo-locating clicks and squeaks and respond with spectacular aerobatics as the bat gets too close for comfort. In addition to phenomenal hearing and sense of smell mantises have enormous compound eyes which they use to locate their prey during the daytime. (See also: ‘Animal Senses’ and 'eyespots')
Other articles by John Blatchford
