{"id":404,"date":"2020-08-16T15:49:44","date_gmt":"2020-08-16T15:49:44","guid":{"rendered":"https:\/\/keepingbugs.com\/?page_id=404"},"modified":"2021-08-01T10:39:04","modified_gmt":"2021-08-01T10:39:04","slug":"basic-phasmids-info","status":"publish","type":"page","link":"https:\/\/keepingbugs.com\/basic-phasmids-info\/","title":{"rendered":"An introduction on the biology of phasmids"},"content":{"rendered":"\n

On this page, we’ll dive in the wondrous world of phasmids – better known as stick insects, walking sticks of leaf insects. This bug is a favourite to keep as an exotic pet. Their strange shapes and interesting behaviour makes them very intriguing to keep. Generally speaking, they are relatively easy to take care of. <\/p>\n\n\n\n

There are over 3000 species of phasmids described, and there are many different species kept in captivity. The Indian stick insect, also known as the ‘common’ stick insect, is as its name suggest one of the most known and popular stick insects. But there is more to discover than its extraordinary shapes only. We will give you more information about their morphology, their life cycle and natural behaviour. <\/p>\n\n\n\n

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Phasmid, Phasmida, Phasmatoptera or Spectra<\/span><\/div><\/div><\/div>\n\n\n\n
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Phasmatodea<\/em><\/span><\/div><\/div><\/div>\n\n\n\n
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1.5cm (0.6″) – 56.7cm (12″) <\/span><\/div><\/div><\/div>\n\n\n\n
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1gr – 65gr<\/span><\/div><\/div><\/div>\n\n\n\n
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4 months – 3 years<\/span><\/div><\/div><\/div>\n<\/div><\/div>\n<\/div>\n\n\n\n
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Morphology<\/h2>\n\n\n\n

Like many other insects, phasmids have six legs, an exoskeleton and its body exist of 3 bodyparts- the head, thorax and the abdomen. Some have wings and can do some controlled of uncontrolled flights, but many species are wingless or have underdeveloped wings. So they mostly rely on the often very long and adapted legs. Although many phasmid species have long or strange shaped legs, they can move quite quickly, with every part of legs have its own function. Their hind legs are most functional as power. Their middle legs are responsible for steering. Their front legs probe the surface and the environment.<\/p>\n\n\n\n

Phasmids, better known as walking sticks, do give credits to their name. They are among the largest of all insects with often very slim bodies. Where some just as tiny as 1.5 cm (0.6″) there are species tot grow to over 30 cm (12″). The longest stick insect even measures up to 56.7 cm (22.3″). Despite being relatively long, their weight is almost nothing but a couple of grams. <\/p>\n\n\n\n

Phasmids have exaggerated sexual dimorphism, which means that the males and females look very different and can be determined by how they look. Females are almost always larger than males. Sometimes even two or three times bigger. Also, males are often thinner than females. <\/p>\n\n\n\n

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The giant prickly stick insect (Extatosoma tiaratum<\/em>) have a body covered with thorn-like spikes primarily as camouflage. It is a beautiful species to keep. <\/figcaption><\/figure>\n\n\n\n

Camouflage, colouration and predator avoidance <\/h3>\n\n\n\n

Almost everyone knows phasmids of their camouflage. Their body, often including legs, are designed to mimic the form of a stick or leaf. They rely on this camouflage to evade predators and can remain absolutely stationary so that predators do not see them. Phasmids are true masters of mimicry, and some species will take it even a step further. Some make rocking motions to mimic the movement of leaves and twigs in the wind. Some species use catalepsy (feigning death) as a strategy to avoid predation. The nymphs of the spiny leaf insects have been known to mimic ants by moving their abdomen upwards. <\/p>\n\n\n\n

Besides, some species use active defence beside their camouflage. For example, some species have large spines on their leg and when at danger from a predator will move their spiny legs rapidly to inflict painful wounds. Some species are even venomous and use poison to attack predators. These phasmids often don’t use camouflage anymore and have bright colours. <\/p>\n\n\n\n

Many phasmids have another, more extreme, defence mechanism that is known as autotomy. It means that a stick insect can break off a leg at a weak point using a special muscle. Phasmids can regenerate missing limbs every time they moult. It can take several moults to regenerate a limb fully. When at the adult stage a stick insect or leaf insect won’t moult anymore, and so can’t regrow a limb anymore (however, there are some cases an adult can force themselves to moult in order to regrow a lost leg). <\/p>\n\n\n\n

Life cycle<\/h2>\n\n\n\n

Phasmids belong to the group of hemimetabolous insects – which means they develop through a series of several nymphal stages called instars – and not undergo a complete metamorphosis as butterflies and beetles do. Newborn phasmids moult around 4 to 9 times. With every mould, the nymph will grow until it reaches the adult size. They cannot grow between moults because of their exoskeleton.<\/p>\n\n\n\n

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    There are many different shapes and structures between all phasmids (left: photo by Dr\u00e4g\u00fcs). However, every phasmid egg is pretty small like you can see on the right. <\/figcaption><\/figure>\n\n\n\n

    Eggs<\/h3>\n\n\n\n

    Most phasmid females randomly drop their eggs where they fall on the ground. Some females have other strategies, like bury their eggs in the soil, glue their eggs to a suitable surface, or pierce them into a leaf or shooting eggs far away. A single female will “lay” 100 to 1000 eggs in her life. <\/p>\n\n\n\n

    Hatching times can diverse immensely, like a few weeks to a couple of months. It also depends on the condition of the environment of the eggs. <\/p>\n\n\n\n

    Even eggs have camouflage. Eggs look like seeds in shape, size, and even feel like seeds. Just like seeds have, these eggs have a lid-like structure from where the nymph will emerge. Some eggs attract ants, and they will take them to the ant nest, where it will have the defence of the ant colony. <\/p>\n\n\n\n

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