{"content":[{"text":"Caterpillars are the larval stage of butterflies and moths. They are voracious eaters , usually \n feeding on fresh fruits and vegetables. For this reason, caterpillars are considered major \n agricultural pests, though some species actually help control overgrowth by feeding on pest \n plants. Caterpillars come in many colors, shapes, and sizes. Some caterpillars are quite hairy, \n while others are smooth. Despite differences between species, though, all caterpillars share \n certain morphological features. These parts are labeled in the diagram above. The first section \n of the cate rpillar body is the head. It includes six eyes called stemmata , the mouthparts, the \n small antennae, and the spinnerets, from which the caterpillar produces silk. Antennae are \n present on either side of the labrum but are small and relatively inconspicuous. The labrum is \n like an upper lip. It is used to hold food in place while the mandibles do their chewing. It \n consists of three segments, known as T1, T2, and T3. The thorax contains three pairs of true \n legs with hooks and a dorsal plate called the prothoracic shield. The prothoracic shield is \n located on T1, the first segment. The color pattern of this shield is valuable for identifying \n different species of caterpillars. It is 10 segments long, classified as A1 through A10, and \n includes the prolegs false legs , most of the spiracles breathing holes used for respiration , and \n the anus the final stop along the digestive tract. A segment is a body section of the thorax or \n abdomen. A caterpillar has three thoracic segments and 10 abdominal segments. The horn is a \n dorsal projection present on some caterpillars such as hornworms. It may also be used to \n frighten away predators. Prolegs are fleshy, false, unsegmented legs, usually found in pairs on \n the third through sixth abdominal segments. Experts sometimes use the arrangement and the \n length of these hooks to identify caterpillars at the family level. The number and size of the \n prolegs can also be identifying characteristics. The caterpillar contracts muscles to open and \n close the spiracles. There are three pairs of segmented legs, also known as thoracic legs or true \n legs, located in pairs on each of the three thoracic segments. These are distinct from the fleshy, \n false prolegs found along the abdominal cavity. Located in the head section, the mandibles are \n jaws that are used for chewing leaves. The anal prolegs are a pair of unsegmented, false legs \n that are located on the last abdominal segment. The prolegs on A10 are usually well developed. \n Share Flipboard Email. Debbie Hadley. Entomology Expert. Debbie Hadley is a science educator \n with 25 years of experience who has written on science topics for over a decade. Updated \n December 11, Cite this Article Format. Hadley, Debbie. Insect Anatomy: The Parts of a \n Caterpillar. The diagram highlights the basic common anatomy of an adult butterfly or moth. \n The sections, divided according to butterfly or moth parts, provide more specific descriptions of \n the various appendages of these beautiful insects. The parts are indicated by numbers, which \n correspond to the sections. The forewings are the anterior wings , which are attached to the \n mesothorax the middle segment of the thorax. Scent scalesâ€”modified wing scales on the \n forewing of male butterflies and mothsâ€”release pheromones which are chemicals that attract \n females of the same species. The posterior wings, attached to the metathorax the last segment \n of the thorax , are called the hindwings. Indeed, moths and butterflies can still fly, even if their \n hindwings are cut off, they note. The antennae also help with balance and orientation. \n Interestingly, the antennae of a butterfly have rounded clubs on the ends, whereas, in moths, \n they are often thin, or even feathery. The second section of the butterfly or moth body, the \n thorax consists of three segments, fused together. Each segment has a pair of legs. Both pairs \n of wings also attach to the thorax. All three parts of the body are covered in very small scales, \n which give the butterfly its color. The third section is the abdomen, which consists of 10 \n segments. The final three to four segments are modified to form the external genitalia. \n Ommatidia work together to enable the butterfly to see what's around it. Some insects may have \n just a few ommatidia in each eye, while butterflies and moths, as noted, have thousands. The \n first pair of legs, attached to the prothorax, is called the forelegs. The legs of a butterfly have \n chemoreceptors on its tarsal segments. This helps them to smell and taste. The middle pair of \n legs, attached to the mesothorax, are the midlegs. Butterflies can locate food sources by simply \n using their chemoreceptors on their legs. Female butterflies, for example, can identify if a plant \n is a good location on which to lay eggs. The plant releases a chemical after the female butterfly \n drums its legs on a leaf, which the female butterfly picks up with its chemoreceptors. The last \n pair of legs, attached to the metathorax, are the hind legs. The middle and hind legs are the \n pairs that are made for walking. The muscles of the thorax control the wings and legs. Jantzen, \n Benjamin, and Thomas Eisner. Smart, Paul Chartwell Books. Share Flipboard Email. Debbie \n Hadley. Entomology Expert. Debbie Hadley is a science educator with 25 years of experience \n who has written on science topics for over a decade. Updated December 26, View Article \n Sources. Cite this Article Format. Hadley, Debbie. The Parts of a Butterfly. Switch Level. Kids \n Students Scholars. Articles Featured Article. All Categories. Arts and Literature. Earth and \n Geography. Life Processes. Living Things Other. Philosophy and Religion. Science and \n Mathematics. Sports and Recreation. Featured Media. Subscriber features. Email Subscriber","bbox":{"left":0.050964,"top":0.031288,"width":0.8978240000000001,"height":0.894159}}],"images_bbox":[],"images_bbox_not_text_overlap":[]}