Stick insects ( Phasmatodea )
The Phasmatodea (also known as Phasmida or Phasmatoptera) are an order of insects, whose members are variously known as stick insects in Europe and Australasia; stick-bugs, walking sticks or bug sticks in the United States and Canada; or as phasmids, ghost insects or leaf insects. The group’s name is derived from the Ancient Greek phasma, meaning an apparition or phantom, referring to the resemblance of many species to sticks or leaves.
Their natural camouflage makes them difficult for predators to detect, but many species have a secondary line of defence in the form of startle displays, spines or toxic secretions. The genus Phobaeticus includes the world’s longest insects.
- Kingdom: Animalia
- Clade: Euarthropoda
- Class: Insecta
- Superorder: Exopterygota
- Order: Phasmatodea
- Suborders: Agathemerodea
Stick insects belong to the Order of Phasmatodea. Like any insect, an stick insect has 6 legs and 2 antennae. Some species have wings when adult, most species do not. The shape and size of their body differs a lot between species; some are long and thin, others bulky and covered in strange shapes that mimic thorns, leaves or moss. Only very few species do not trust on their camouflage, but invented other means of protection from predators.
Stick insect species, often called walking stick, is a North American small, semi-inch-long Time Cristina size series, Borneo’s 13-inch-long Phobtikis Kirby. This huge foot extends beyond its feet by more than 21 inches, making it the world’s longest insects. Female are usually larger than males.
Stick insects make rhythmic, repetitive side-to-side movements. This is like vegetation moving in the wind.
Also, the swaying movements may help the insects see objects against the background. Rocking movements by these sedentary (sitting) insects may replace flying or running as way to define objects in the visual field.
Some species of phasmid are able to produce a defensive spray when threatened. The spray contains pungent-smelling volatile molecules which the insect gets from its food plant. The spray from one species, Megacrania nigrosulfurea, is even used as a treatment for skin infections by a tribe in Papua New Guinea by virtue of its antibacterial constituents.
Because stick insects make a very nutritious and filling meal for many birds, reptiles, spiders, and primates, they are mostly nocturnal so as not to be found so easily. Even though stick insects can sometimes avoid diurnal predators, they are not safe from bats.
Echolocation used by bats can help them hone in on the tiny noises made by stick insects for a tasty meal. The stick insects’ elaborate camouflage doesn’t help them in the dark. It’s a good thing bats are not fooled by stick insect camouflage; without bats to eat them, we could find ourselves living a little too close for comfort with millions of stick insects!
The life cycle of the stick insect begins when the female deposits her eggs through one of these methods of oviposition: she will either flick her egg to the ground by a movement of the ovipositor or her entire abdomen, carefully place the eggs in the axils of the host plant, bury them in small pits in the soil, or stick the eggs to a substrate, usually a stem or leaf of the food plant. A single female lays from 100 to 1,200 eggs after mating, depending on the species.
Many species of phasmids are parthenogenic, meaning the females lay eggs without needing to mate with males to produce offspring. Eggs from virgin mothers are entirely female and hatch into nymphs that are exact copies of their mothers.
Stick insect species that are the product of hybridisation are usually obligate parthenogens, but non-hybrids are facultative parthenogens, meaning they retain the ability to mate and their sexual behavior depends on the presence and abundance of males.
Phasmids generally mimic their surroundings in color, normally green or brown, although some species are brilliantly colored and others conspicuously striped. Many stick insects have wings, some spectacularly beautiful, while others resemble little more than a stump. A number of species have spines and tubercles on their bodies.
Stick insects ( Phasmatodea ) images