Stick Insect Anatomy 101

Zoologists are scientists that study the animal kingdom, and they classify stick insects within a group known as Phasmatodea. From stick insect anatomy, through to examining their living habits, zoologists cover it all. Phasma is the Latin for ghost, and the animals classified as Phasmatodea are insects with excellent camouflage skills.

Stick insects have the natural camouflage of looking like the branches that make up their natural habitat: green and brown varieties have evolved, and there are also some that can change their color. They are creatures of stealth and some come out only at night to avoid detection. Another trick to avoid being identified is the ability to move back and forth in a motion that mimics foliage blowing in the breeze, and the Indian Stick Insect even has the ability to fake death by falling with its legs folded in (a practice known as catalepsy).

In addition to camouflage these insect have other defenses against predators. Some are winged and able to fly away. In some species these wings are brightly colored and this gives off a flash of color as they launch their escape which predators take as a sign that they are poisonous and not a suitable snack. Some species ward off predators by mimicking scorpions when they are nymphs (baby stick insects) – this is something that is most common in the larger species which have a broad body suited to curling the abdomen over the torso in a scorpion-like fashion. These larger stick insects also often have spikes protruding from their bodies and legs. There are species that can use their legs, with protruding spikes, as pincers to stab predators. The Florida Stick Insect (Anisomorpha buprestoides) is a good example of chemical defense, something which is quite rare in this species, but which can be quite effective. Whilst the Florida Stick Insect can temporarily blind its predators (including humans), most chemical defenses are limited to unpleasant odors.

There are over 2,500 species of Phasmatodea, but only a fraction of these have been kept and studied by zoologists. If you start off by keeping stick insects, and the hobby grabs you, then you can move on to breed and keep rarer species, and make a genuine contribution to scientific study. What we know about these insects is based on the study of just a few hundred.

Zoologists have looked at stick insect anatomy  in some detail, and its body can be divided into three basic parts. The head has two distinctive antennae which provide sensory information, the thorax (which itself is made up of three parts) is the middle of the body, and the abdomen is the final part of the body and leads to genitalia (a genital opening to be precise). The thorax sections are:

• prothorax which has the first pair of legs attached to it
• mesothoracic segment, which has a pair of legs and sometimes wings
• metathorax, which has a pair of legs and sometimes wings

Sticks insects come in all shapes and sizes depending on the habitat they are imitating, so the study of insect anatomy is a broad one.