How to Identify a Caterpillar

Do you know how a caterpillar transforms into a beautiful butterfly? Well, the life cycle of butterflies starts with the laying of eggs. In the second stage, these eggs hatch into larvae. Caterpillars are larval form of butterflies, moths and some insects. It is in the third stage of the life cycle of butterflies that the caterpillar changes into pupa. The fourth stage ends with the pupa metamorphosing into an adult butterfly. In this article, we will try to gain an insight into the types of caterpillars and how to identify them.

Physical Characteristics of Caterpillars

As mentioned earlier, the larval stage is commonly referred to as caterpillars. Once the eggs hatch and these worm-like larvae are out, most of their time is spent in feeding themselves and shedding their skin. The stages during which they change their skin is referred to as 'instars'. They have segmented bodies, with three pairs of true legs and five pairs of false legs (prolegs) present on their abdomen. The first three segments that are located behind the head are known as the thoracic segment. The remaining segments, also known as the abdominal segments, contain five pairs of prolegs. The prolegs are a defining feature of a caterpillar.

The number of prolegs and their positioning might vary depending on the types of butterfly or moths. The breathing mechanism of caterpillars is associated with their movement. The exchange of air is facilitated by the compression and extension of the segments of their body. They use various protective mechanisms to protect themselves from predators. Some of them can detect the presence of predators through vibrations and camouflage themselves when they feel threatened. They produce silk strands and use these strands to attach themselves to leaves. Some use the silk strands to drop off from leaves when they sense any danger. Some of them are poisonous and sting. Now that you have some idea about the features of caterpillars, let's find out how to identify a caterpillar.

Caterpillar Identification

Geometrid, skippers, hornworm, prominents, false unicorn, regal moths, silk moths, swallowtails are some of the common types of caterpillars. One can identify caterpillars if one has some idea about the distinct features of various caterpillars. You must have an idea about their body color and patterns for identifying caterpillars. The presence of hair, spikes, horn or tail could also help in identification of caterpillars. For instance, the hornworm caterpillars are about 3-5 inches in length. Their main body color is green and the white striped pattern at the sides makes them quite distinct. The presence of a horn at the rear is a defining feature of this caterpillar.

Since some of the caterpillars might have the same body color, identification can become difficult. For instance, if you wish to gain an insight into green caterpillar identification, you cannot identify by looking at the main body color. You need to look for patterns and other features. The luna moth, imperial moth and American dagger moth larvae are green in color, but the presence of yellow to magenta colored dots along the back side can be used for identifying a luna moth. American dagger moth is about 2-3 inches long and has black spines, whereas imperial moth is about 4 inches long and is very fuzzy.

Tent caterpillars make tent-like structures and use these structures for housing and protecting several caterpillars. They produce silk strands from their glands and these tough strands of silk are used for creating these nests in the trees. These can be seen on apple, cherry and other fruit-laden trees. These caterpillars are about two inches long and are covered with hair. A white stripe can also be seen along their back. These are voracious eaters and can cause a lot of damage to the foliage.

Saddleback caterpillars are larvae of brown moth. Less than an inch in length, they are brown in color. The middle part of their body is green in color. The presence of a white dot in the head and at the rear end and prominent horns are the defining features of this poisonous caterpillar. The presence of poisonous spines on its body helps in protecting it from predators. Have you ever seen the larval form of tiger moths? Well, these caterpillars belong to Archiidae family are called woolly bears due to their dense coat of hair. Monkey slug or hag moth larva is one such caterpillar which has a very strange shape. Unpredictable body plans and stinging mechanism is used by such caterpillars to protect themselves from predators.

The larval stage of swallowtail butterflies have fine hair on their bodies and have vibrant colored bodies. Morning glory prominent or false unicorn can be identified due to the presence of a hump in its fifth segment. While its main body color is light brown, you can see green coloration on its second and third segments. Geometrids can be identified with the way they move. These caterpillars use their initial segment and false legs on the last segment and form loops while moving, therefore these are also referred to as loopers.

The best way to identify caterpillars is to look for distinct features. There are various types of caterpillars, therefore, it is not possible to describe all. Those who wish to learn more about caterpillars can go through the caterpillar identification chart and learn about different types of caterpillars and their features.