Caterpillar — it is a larva (child) of a butterfly and a moth. After about 2-3 weeks, the caterpillar becomes a cocoon, and turns into a chrysalis after another 2 weeks. Then a caterpillar with regrown wings appears. The caterpillar is well known as a pest, especially in the textile industry. One species of caterpillar destroys silk in the Far East, it is known as the silkworm.
Origin of the species and description
Photo: Caterpillar
There are over 20,000 species of caterpillars worldwide, and it is estimated that there are many others that have not been discovered as new species of butterflies and are regularly found in regions where there is little, if any, human presence. Generally, most caterpillar species are agricultural pests, as they can burrow through fields, often leaving huge holes that spoil plants.
Interesting fact: Some types of caterpillars are highly poisonous, especially those that live in tropical forests. Other species are venomous only in caterpillar form, meaning that when they turn into a butterfly or moth, they no longer have venom.
Video: Caterpillar
Butterflies and moths spend their youth in the form of caterpillars, called the larval stage. Caterpillars feed constantly. They outgrow their skin and shed it several times. After the last molt, the caterpillar attaches to the branch and enters the pupal stage.
Fun fact: Moth caterpillars use a silk thread from their silk glands to spin a protective cocoon. Inside the cocoon, the pupa goes through a process called metamorphosis. The six front paws of the caterpillar turn into paws of an adult insect, the other paws disappear, wings grow, and the insect appears in the form of a beautiful butterfly.
Caterpillars vary in size, color, and appearance depending on their species. Some caterpillars are brightly colored, while other species look rather dull in comparison. Some types of caterpillars are hairy while others are smooth. The main purpose of the — scare predators and keep them from being eaten.
Appearance and Features
Photo: What a caterpillar looks like
The most common caterpillars are:
- large white caterpillar (Pieris brassicae), adults of which are called cabbage white butterflies. Caterpillars accumulate high concentrations of mustard oil in their diet, and their bright, spotted body alerts would-be predators to their unpleasant taste;
- small tortoiseshell caterpillar (Aglais urticae). Living together benefits caterpillars because they can combine their bodies in unison, acting as one large organism, trying to scare off predators. Eventually, individual caterpillars crawl away separately to pupate. Turtle caterpillars can be seen from May to June, with adults potentially active throughout the year;
- caterpillar-comma (Polygonia c-album). Caterpillars change color quite extensively throughout their larval stage, but older caterpillars are most characteristic. Burnt orange-and-black cubs develop a white “saddle” mark, reminiscent of a dropping bird, which scares off predators;
- bloody bear caterpillar (Tyria jacobaeae). Growing to 28mm, these black and yellow caterpillars are very distinctive and easy to identify as they look like they are wearing a rugby shirt;
- silver hole caterpillar (Phalera bucephala). This black and yellow caterpillar reaches 70mm in length and has hairs that irritate humans and are good at defending themselves against predators;
- Pale tubercle moth caterpillar (Calliteara pudibunda). Caterpillars can grow up to 45mm and reach full size in about two months. The bristles on the caterpillar's body are known to cause skin irritation in humans. Adults are a beautiful gray moth with comb-like antennae;
- maple caterpillar (Acronicta aceris). This is an urban species, characterized by bright orange hair and black and white diamond patterns along the back;
- psi arrow caterpillar (Acronicta psi). After hatching from eggs that take only a week to hatch, the caterpillars grow up to 40 mm in about thirty days. Gray caterpillars can be found from July to early October. The whitish adults are active from mid-May to August. Their yellow stripe serves as camouflage on plant stems.
Now you know what a caterpillar looks like. Let's find out where this insect is found.
Where does the caterpillar live?
Photo: Caterpillar in nature
The large white caterpillar is only 45mm long and is fed on cabbage, lettuce and nasturtium for four weeks — therefore, farmers and gardeners consider them pests. The green eggs of the small tortoiseshell caterpillar are laid in groups on stinging nettles, and the spiny black and yellow caterpillars then live together, forming a common silken web and feeding on nearby leaves to grow up to 30mm in length. As they grow, they move on to new plants and build new webs, leaving behind old, skin-full sheds;
The comma caterpillar grows up to 35 mm and lives on hops and nettles. These caterpillars can be found from late April to mid-September, but the butterflies are active all year round. They experienced a notable decline in the 1800s, probably due to a reduction in the planting of their favorite food, hops, but have since experienced a resurgence. Bloody bear caterpillars pupate underground, not in a chrysalis in a tree like other caterpillars. Adults fly from May to early August. Population fluctuations «boom and bust» locally.
Caterpillars of the silvery hole fully grow in 30 days and pupate underground during the winter. Cone-tipped moth caterpillars are found from July to early October. The adults are active from late May to July and their markings are designed to look like they have a broken wing. Pale tubercle moth caterpillars have been found on various broad-leaved trees and shrubs, including birch and hops. They can be seen from the end of June to the beginning of October, but in autumn they are more often seen when they crawl in search of a place to pupate. Adults fly from July to August.
The maple lancet caterpillar lives on sycamore, horse chestnut, as well as cultivated and field maples. Caterpillars are found from July to September. In winter, they pupate on the ground, in debris that looks like bark and fallen leaves. Adults are active from mid-June to early August.
What does a caterpillar eat?
Photo: Red Caterpillar
The caterpillar is a herbivore, but caterpillar and butterfly diets are different. Butterflies use straw-like tongues to drink nectar from flowers, which is an adaptation that occurs in the process when a caterpillar turns into a butterfly. Caterpillars feed primarily on leaves, plants, and flowering plants, and large holes can often be found in leaves, indicating the presence of a caterpillar.
Fun Fact: Caterpillar — this is a real food machine — cylindrical bag for plant digestion. During the few days or weeks it is active, the caterpillar will gobble up its own weight many times over, whatever the food it chooses.
For example, the comma caterpillar feeds on the underside of leaves when young, but as it grows, it begins to feed on the upper side. The feeding pattern of the bloody bear caterpillar is distinctive, giving a shredded appearance to the common slaughterhouse they feed on. These caterpillars feed in groups, mainly during the daytime, from July to early September. When the leaves of the plant disappear, they sometimes resort to cannibalism.
The caterpillar of the silver hole feeds on oak leaves. After hatching from the egg cluster, the larvae feed together, leaving alone when they grow to large sizes. Caterpillars of the maple shooter, whose length reaches 40 mm, sometimes fall from the trees on which they feed. Psi-shooter caterpillars feed on broad-leaved trees and shrubs such as hawthorn, apple and birch.
Many species of caterpillars are known to be carnivorous and feed on a variety of insects. Most caterpillars are herbivores and feed primarily on leaves, although some species feed on all parts of the plant, fungi, and dead animals, including other caterpillars.
Character and lifestyle features
Photo: Black Caterpillar
Caterpillars can be great transformers as they literally transform from wavy worms into beautiful butterflies, but that's not their only transformative trait. Caterpillars are often camouflaged among plants due to their coloration, and their fuzzy skin often looks like thorns on a branch. This camouflage ability helps caterpillars survive until they reach full maturity and begin metamorphosis from chrysalis to butterfly.
The pupation stage begins with an adult caterpillar that attaches itself to a tree bark or other hard object and then splits the skin to reveal a chrysalis. The transformation takes place inside the chrysalis when the caterpillar begins to disintegrate into liquid, and only a few remaining cells turn into an adult butterfly.
After the caterpillar has completed its metamorphosis into a butterfly, it will open and a butterfly will appear. It does not waste time mating and laying eggs, as most butterflies have a short lifespan — few weeks. Butterfly eggs hatch caterpillar larvae and the cycle begins again.
There are usually six metamorphic transformations in a butterfly's growth path, each stimulated by the release of the molting hormone ecdysone from the prethorax. The juvenile hormone secreted by the endocrine gland slows down progress in adulthood: although the level of the hormone is high, it keeps the caterpillar in the larva.
However, juvenile hormone secretion slows down over time. Only when it falls below a critical level does molting lead to pupa and pupation. During this time, there is a massive redistribution of nutrients, and adults may finally have features. When the level of juvenile hormone drops to almost zero, the last molt occurs in an adult.
Social structure and reproduction
Photo: Pair of caterpillars
Caterpillars are ready to become butterflies from birth. Even in the smallest caterpillar, freshly hatched from the smallest egg, the tufts of cells for organs such as antennae, wings, paws and genitals are already primed and destined to become adults. Called imaginal discs (being flat and round), they cannot grow and develop due to the constant washing out of juvenile hormone.
As the larva feeds, its intestines, muscles, and some other internal organs grow and develop, but the imaginal discs are temporarily suppressed and remain dormant. The caterpillar behaves like a free-living, feeding, growing, but repressed embryo.
When it reaches a critical size, the molting hormone, ecdysone, is released. She sheds her skin several times in response to ecdysone, each time forming a new instar (stage), but juvenile hormone keeps it in the caterpillar, preventing further development until its concentration approaches full size, and the concentration of the latter decreases.
At the fifth and last age of the caterpillar, the imaginal discs are already beginning to emerge from their forced dormancy and grow. The juvenile hormone now falls below the threshold and the next burst of ecdysone stimulates chrysalis. Flattened imaginal discs begin to develop unhindered. Each folds into a concave dome, then takes the shape of a sock. The center of each disk is meant to be the end of the — the tip of a paw or the tip of a wing.
Most of the plump mass of the caterpillar is processed into adult features that merge into the inner shell of the pupa. At this stage, the interior consists mainly of a nourishing soup, nourishing the embryonic imaginal discs as they complete their delayed development. The latest surge of ecdysone comes in the midst of near-zero juvenile hormone — and stimulates the emergence of an adult butterfly to mate, disperse and lay eggs.
Caterpillars' natural enemies
Photo: What a caterpillar looks like
Because of their small size and worm-like shape, caterpillars are preyed upon by many animal species, but the caterpillar's main enemies are birds and insects. Caterpillars are also often preyed upon by small mammals and reptiles.
Caterpillars cannot easily escape from predators because they move slowly and do not yet have wings. This means that they either have to rely on camouflage to keep predators from noticing them (which gives us caterpillars that look like leaves, plant stems, etc.) or they have evolved to be bright and sharp, so whatever, who might want to eat them know it would be a bad idea.
Caterpillars are found in almost all climates around the world, making their predators abundant.
In addition to birds, caterpillars feed on:
- people – caterpillars are a delicacy for people in parts of the world such as Botswana in southern Africa, as well as in East Asian countries such as China. In fact, caterpillars are harvested daily in these areas due to their high nutritional value. Compared to beef, lentils and fish, caterpillars are higher in protein and fat;
- Wasps are known for carrying caterpillars to their nests as food for their babies. Wasps are useful to the garden as they often catch caterpillars of almost any size, thus keeping them under control. However, wasps feed on caterpillars mainly in spring and early summer. As the season grows, their population becomes acidic and their diets change to more sugary ones;
- ladybugs — small, rather round, brightly colored and spotted beetles that feed mainly on aphids. Ladybugs may eat other insects, especially caterpillars. Since aphids and caterpillars are harmful to plants, gardeners use ladybugs to biologically control them. Caterpillars have rather soft bodies and ladybugs find them very tasty, especially small ones.
Population and Species Status
Photo: Caterpillar
Approximately every 10 years there is an outbreak of the population of caterpillars in forests. The caterpillars, which emerge in late June and early July, eat a surprising amount of foliage as they grow. Forest caterpillar species prefer hardwood leaves, especially sugar maple. The current outbreak began last summer, when hordes of hungry caterpillars chewed through many forests. Following previous trends, this outbreak should be over in a year or two, but not before it gets bigger.
Caterpillars in the forest are preyed upon by a species of fly colloquially referred to as the “friendly fly” and the population grows in response to caterpillar growth bursts after a short delay. The forest caterpillar population is also controlled by virus and fungus. These viruses come in the form of protein crystals that occur naturally in the ground and on leaf surfaces. They only affect caterpillars and can cause a high mortality rate during an outbreak.
The removal of leaves by caterpillars is one of nature's regular cycles. There is even evidence that the sheer amount of fecal pellets produced by caterpillars gives trees such a boost of nitrogen fertilizer that they grow more luxuriantly in a post-defoliation year compared to years without defoliation. Although there is no scientific evidence or long-term data from annual sampling, it appears that the caterpillar population is smaller today than it was a few years ago.
A caterpillar is a small, worm-like animal that will build a cocoon and eventually will turn into a butterfly or a moth. Caterpillars have thirteen body segments, with three pairs of short legs on the thorax and several pairs on the abdomen, six eyes on each side of the head, and short antennae. Caterpillars feed mainly on foliage and are usually brightly colored.
