Abdomen - the last segment of an insect's body, located at the tail end. The heart, reproductive organs and much of the digestive systems are located in a butterfly's abdomen.
Abdominal Prolegs - the peg-like legs on the abdomen (hind region) of a caterpillar. These legs have crochets (small hooks) on them. These legs disappear in the adult butterfly.
Adult - the fully grown or fully developed stage of an animal. (A butterfly is the adult stage of a caterpillar.)
Aeropyles - microscopic holes that dot the surface of the egg. Aeropyles let oxygen into the egg.
Androconia - (also called scent scales) are modified wing scales on butterflies and moths that release pheronomes. Only males have these scent scales. The pheromones attract females of that species.
Antennae - (singular antenna) are sensory appendages attached to the head of some adult insects. Antennae are used for the sense of smell and balance. Butterflies have two segmented antennae with a small club at the end of each. Moths have antennae without the club. Larvae (caterpillars) have tiny sensory antennae.
Apical - means towards or at the apex (the uppermost point or top).
Aposematic Coloration - (or warning coloration) is the bright, attention-getting coloration that protects an organism from experienced predators (i.e., predators who have previously eaten a similar-looking animal and have gotten sick from it). Both poisonous organisms (like the Monarch butterfly) and its mimics (poisonous or not) are said to have aposematic coloration.
Army - the term for a group of caterpillars.
Arthropods - a group of animals with exoskeletons made of chitin, segmented bodies and jointed limbs. Insects, arachnids, trilobites, crustaceans, and others are arthropods.
Basking - the activity where a butterfly rests with outstretched wings in the sunshine in order to absorb as much heat as possible.
Batesian Mimicry - when a non-poisonous species has markings similar to a non-related poisonous species and gains protection from this similarity. Since many predators have become sick from eating a poisonous animal, they will avoid any similar looking animals in the future. An example is the non-poisonous Viceroy which mimics the poisonous Monarch (as it turns out, though, the Viceroy is also distasteful, so it is a Mullerian mimic). Henry Walter Bates defined this type of mimicry in 1861.
Brood - a single generation of butterflies that live during the same time period.
Camouflage - a protective coloring that enables a butterfly to blend in with its environment, thus hiding it from predators.
Cell - a closed area of an insect wing that is bounded by veins.
Chalaza - a raised sclerotized (hardened by scleroproteins) portion of the cuticle of a caterpillar that bears one to four setae (tactile hairs); each seta arises from a separate raised area.
Chitin - (Pronounced: Ki - tin) - a tough, colorless material that makes up the butterfly exoskeleton.
Chorion - the hard, protective, outer part of an insect egg.
Chrysalis - the third stage of the butterfly life cycle, also called a pupa.
Clade - a group of all the organisms that share a particular common ancestor (and therefore have similar features). The members of a clade are related to each other.
Claspers - appendages on the rear segment of the male butterfly or moth abdomen. Claspers hold onto the female's abdomen during mating.
Cocoon - the silken protective covering made by a moth larva before it becomes a pupa.
Cold Blooded - having a body temperature that is about the same as the surrounding air because of the animal's inability to regulate their own internal body heat. On the other hand, their bodies stay at a fairly constant temperature, regardless of their surroundings.
Club - the thickened end of a butterfly's antenna.
Clypeus - the hard plate on the top of an of insect's head (part of its exoskeleton). The butterfly's labrum (upper lip) is at the bottom edge of the clypeus.
Compound Eyes - insects (like butterflies and moths) have compound eyes. These eyes are made up of many hexagonal lens/corneas which focus light from each part of the insect's field of view onto a rhabdome (the equivalent of our retina). An optic nerve then carries this information to the insect's brain. They see very differently from us; they can see ultraviolet rays (which are invisible to us).
Costa - the front (anterior) margin of a butterfly or moth's wing - the leading edge of the wing.
Costal Fold - a fold on a male butterfly forewing's leading edge. This fold contains the male's scent scales (the scent scales are also called androconia).
Cremaster - a support hook (or a cluster of small hooks) at the abdominal (hind) end of a pupa.
Crepuscular - active at twilight or just before dawn.
Cryptic Coloration - a type of coloration in which an organism matches its background, hiding (camouflaging) it from predators and/or prey (like the peppered moth.)
Diapause - a period of suspended growth or development in the life of some insects, mites, snails and crustaceans. Butterflies and moths enter diapause when the weather is too severe or food or water is unavailable.
Diurnal - most active during the daytime.
Dormancy - a period of no activity, when development is suspended, often occurring during unfavorable conditions.
Ecdysis - (Molting.) When an insect molts it loses its old exoskeleton and grows a larger one to replace it. Caterpillars molt four to five times during their development.
Ecdysone - the molting hormone of insects. It causes an insect to molt.
Egg - the first stage in a butterfly's life cycle. The larva or caterpillar hatches from a butterfly egg.
Eruciform - having a caterpillar-like shape (cylindrical with a well-developed head and legs). The larvae of butterflies and moths (caterpillars) are eruciform.
Exoskeleton - a tough, external covering made of chitin, which supports the body and protects the internal organs.
Eye spot - a circular, eye-like marking found on the wings of some butterflies or the body of some caterpillars. These eyespots make the insect look like the face of a much larger animal and may scare away some predators.
Filaments - (also known as tentacles). These fleshy appendages provide sensory information for the caterpillar. They are often mistaken for antennae. Monarch caterpillars have two pairs of filaments.
Forewings - the two upper wings of flying insects, like butterflies and moths.
Frass - caterpillar waste, which is pellet-like. Caterpillars produce a lot of frass.
Girdle - a silken thread that a caterpillar wraps around its body as a support, attaching the larva to a twig or leaf as it is about to enter the pupa stage.
Head - the front body segment of a butterfly. The mouth parts, eyes and antennae are located here.
Heart - butterflies and moths have simple, flexible, tube-like heart in the abdomen. It pumps blood through a tube that runs from the abdomen to the head, and eventually into the animal's tissues. Pressure gradients force the blood back to the heart and the process begins again. The blood carries nutrients, but not oxygen (which is carried through a series of spiracles)
Hemocoel - (also spelled haemocoel) is the cavity found in insects (including butterflies) that contains the hemolymph.
Hemocyte - (also spelled haemocyte) is an insect blood cell.
Hemolymph - (also spelled haemolymph) is the circulatory fluid (composed of blood and other fluids) found in invertebrates (including butterflies) that fills the hemocoel.
Herbivores - animals that eat plants. Most butterflies are herbivores.
Hibernation - also referred to as overwintering, the act of entering a time of dormancy or inactivity that lasts through a specific period of time (such as a season), enabling a butterfly to survive through a severe winter. Butterflies that hibernate in the winter may do so at any stage of development, depending on the species. Most often, however, hibernation occurs during during the pupal stage hibernation.
Hibernaculum - a leafy structure that is made by some caterpillars when they hibernate (become dormant for period of time during cold weather). The hibernaculum is often made by folding a leaf over and securing it with silk.
Hibernation - (also called overwintering) is a condition in which an animal is dormant for period of time. Some butterflies and moths hibernate during cold weather.
Hill Topping - a behavior seen in some butterflies (like swallowtails) in which butterflies gather at a hilltop (or other high point). This congregating probably helps the butterflies find mates.
Hindwings - the two lower wings of flying insects, like butterflies and moths.
Holometabolous - insects undergo a complete metamorphosis, having distinct larval and pupal stages in the life cycle. Butterflies and moths are holometabolous.
Holarctic - a zoogeographic region that extends from the North Pole to 30-45° latitude. Some holarctic lepidoptera (about 700 butterfly species) include the Monarch, the Zebra Swallowtail, the California Dogface, and the Great Purple Hairstreak, and many more moth species.
Honeydew - a sweet chemical solution that some caterpillars (and other insects, like aphids) secrete in order to attract and feed other insects (like ants).
Host Plant - a plant upon which an insect lays its eggs. Butterflies and moths have very specific host plants. A few species can vary their host plant with season and geography. The host plant of the Monarch butterfly is milkweed (genus Asclepius). When the larvae hatch, they eat the leaves of the host plant.
Imaginal Discs - clusters of cells carried with a larva. Different clusters of these cells will develop into different adult body parts. For example, one cluster will develop into the adult's compound eyes, another cluster will become the antennae.
Imago - adult stage of an insect (like a butterfly or moth) during which the insect reproduces.
Insects - (meaning "segmented" in Latin) have exoskeletons and six legs. They evolved during the Silurian Period, 438 to 408 mya, long before dinosaurs existed. Butterflies and moths are insects
Instinct - a way of behavior that is natural to a butterfly from birth. The behavior is known without having been taught.
instar - an insect between two molts. A newly-hatched insect is called a first-instar or larva. An adult is a final instar. Most caterpillars (butterfly and moth larva) have five or six instars.
Integument - an insect's hard outer coat.
Invertebrates - animals that do not have a backbone. Some invertebrates include insects (like butterflies and moths), crustaceans, sponges, arachnids, jellyfish, etc.
Johnston's Organ - an organ at the base of a butterfly's antennae. This organ is responsible for maintaining the butterfly's sense of balance and orientation, especially during flight.
Kingdom - the highest grouping of similar organisms. A kingdom contains one or more phyla (plural of phylum). Life on Earth is divided into five kingdoms: Animalia (animals), Plantae (plants), Fungi, Protista (protozoans and eucaryotic algae), and Monera (blue-green algae)
Labial Palps - the mustache-like scaly mouthparts of adult butterflies that are on each side of the proboscis. These palps are covered with sensory hairs and scales, and test whether something is food or not.
Labium - the lower "lip" of insects (like butterflies and moths). It is below the butterfly's proboscis.
Labrum - the upper "lip" of insects (like butterflies and moths). It is above the butterfly's proboscis.
Larva - the worm - like second stage of the butterfly life cycle, also called a caterpillar.
Legs - butterflies and moth, like other insects, have six jointed legs in their adult stage. These three pairs of legs are attached to the thorax, one pair in each segment of the thorax.
Lek - a lek is an aggregation of males gathered to engage in competitive displays and courtship rituals, known as lekking, to entice visiting females which are surveying prospective partners to mate with. A lekking species is characterized by male displays, strong female mate choice, and the conferring of indirect benefits to males and reduced costs to females.
Lepidoptera - (meaning "scale wing") is an order of insects that is characterized by having four large, scaly wings and a spiral proboscis. Butterflies and moths belong to the order Lepidoptera. There are about 150,000 named species of butterflies and moth (over 87% are moths).
Lepidopterist - a scientist who studies butterflies and moths.
Life Cycle - the phases or changes that a butterfly goes through from the egg stage until its death as an adult.
Linnean System - a method of classifying organisms based on a simple hierarchical structure. Organisms are divided into groups using the following system: Kingdom, Phylum, Class, Order, Family, Genus and Species.
Lycaenidae - the gossamar-winged butterflies (family Lycaenidae) include the hairstreaks, coppers, blues, and harvesters. They are small butterflies - some have a tail-like projection on the bottom of the hind wings (hence their name - hairstreak). Males have reduced forelegs. The undersides of the wings are speckled. The caterpillars are slug-like.
Malpighian Tubules - clean an insect's blood and deposit the waste into the hindgut for eventual excretion.
Mandibles - tooth like jaws present in insects with chewing mouth parts. (Caterpillars have mandibles, butterflies do not.)
Mating - the pairing of a female and a male in order to breed and produce offspring.
Maxillae - the caterpillar's mouthparts that grasp the food. The maxillae also have taste cells; these chemical detectors tell the caterpillar to eat when the food is appropriate, and not to eat when the food is not appropriate. Caterpillars are very limited in their diet; many species will only eat the leaves of a single type of plant. In the adult stage (butterflies and moths), the maxillae are long, forming the proboscis.
Meconium - the red fluid that butterflies and moths eject after they leave the chrysalis. Meconium is a metabolic waste product from the pupal stage that is expelled through the anal opening of the adult butterfly. (Note: meconium is not blood.)
Metamorphosis - the marked changes in appearance and habitat occur during development, from the growing stage (s) to the mature adult stage. Butterflies undergo "complete metamorphosis" and their appearance changes completely from the larval to the adult stage. (Insects which go through a "simple metamorphosis", such as a grasshopper, change only gradually in appearance during these stages.
Micropyle - the large depression at the top of a butterfly's egg. This small pit marks where the sperm entered the egg. While the egg is developing, air and water enter the egg through the micropyle.
Migration - the mass movement of an animal species across many miles in order to escape unfavorable conditions. Some butterflies such as the Monarch, may migrate thousands of miles in order to avoid winter conditions. Other types of butterflies may only migrate a relatively short distance.
Milkweed Butterflies - members of the family Danaidae. As larva, they eat the milkweed plant. Milkweed butterflies include the Monarch (Danaus plexippus), the Queen (Danaus gilippus), and others.
Mimetic Group or ring - a group of unrelated species that have similar markings which benefits all in the group as they gain protection from predators. Many predators may have gotten sick from eating one of the poisonous species and will avoid all similar looking animals in the future. An example of a mimetic group is the pipe-vine swallowtail, the red-spotted purple, and a few other swallowtails.
Mimicry - when two unrelated species have similar markings. Batesian mimicry is when a non-poisonous species has markings similar to a poisonous species and gains protection from this similarity. Since many predators have become sick from eating a poisonous animal, they will avoid any similar looking animals in the future. An example is the Viceroy which mimics the poisonous Monarch. Müllerian mimicry is when two poisonous species have similar markings; fewer insects need to be sacrificed in order to teach the predators not to eat these unpalatable animals. An example is the poisonous Queen butterfly which mimics the poisonous Monarch.
Molt - to lose the old skin or exoskeleton. The butterfly grows a larger one to replace the one that is shed.
Morph - a variety of a species that is easily distinguished For example, there may be two color morphs of a species of butterfly, one of color A and one of color B.
Müllerian Mimicry - when two unrelated poisonous species have similar markings. Since many predators have become sick from eating a poisonous animal, they will avoid any similar looking animals in the future. Fewer insects need to be sacrificed in order to teach the predators not to eat these unpalatable animals. The Queen Butterfly (Danaus gilippus) is a Müllerian mimic; it is a poisonous butterfly that mimics the poisonous Monarch.
Natural Selection - the process in which some organisms live and reproduce and others die before reproducing. Some life forms survive and reproduce because they are better suited to environmental pressures, ensuring that their genes are perpetuated in the gene pool.
Nectar - the sugary, sweet liquid produced by many flowers.
Nymphalidae - a huge family of butterflies, containing over 5,000 species divided into many subfamilies (including Satyridae, Danaidae, Heliconiidae, and Libytheidae). Butterflies in this family have an under-developed pair of front legs. In the males, there is often a tufted scale sac on these front legs, giving these butterflies the nickname "brush-footed butterflies." This family includes emperors, monarchs, admirals, fritillaries, morphos, and others.
Obtect Pupa - a pupa whose legs are held closely to the body and are unable to move. A butterfly chrysalis is an obtect pupa.
Ommatidia - the parts of an insect's compound eye which receive light from a small part of the insect's field of vision. Each ommatidium is a cylindrical unit composed of a hexagonal lens-cornea and crystalline cone (which receive the light and focus it) plus a rhabdome (which is stimulated by light and sends signals to the optic nerve to the brain).
Order - In classification, an order is a group of related or similar organisms. An order contains one or more families. A group of similar orders forms a class. Butterflies and moths belong to the Order Lepidoptera.
Osmeterium - an orange, y-shaped gland on the neck of some caterpillars. This gland gives off a strong, unpleasant odor when the caterpillar is threatened, keeping away dangerous wasps and flies that try to lay eggs in the caterpillar. Many swallowtails have an osmeterium.
Overwintering - (also called hibernation) is a condition in which an animal is dormant for period of time. Some butterflies and moths overwinter during cold weather.
Oviparous - animals hatch from eggs. Butterflies and moths are oviparous. Butterflies usually lay their eggs on leaves of the plant that the larva (caterpillar) will eat.
Ovipositor - a an organ at the end of the female's abdomen through which she deposits her eggs.
Ovum - egg.
Palps - the mustache-like scaly mouthparts of adult butterflies that are on each side of the proboscis. These jointed palps are covered with sensory hairs and scales. The palps test whether something is food or not.
Patrolling - flying over a specific area in search of a mate.
Perching - landing on a tall plant or other object for the purpose of searching out a mate.
Pharynx - the front part of the foregut between the mouth and the esophagus.
Pheromone - a chemical given off by an animal and meant to cause a specific reaction in another of the same species. (Butterflies give off pheromones in order to attract a mate.)
Phylum - a group of related or similar organisms. A phylum contains one or more classes. A group of similar phyla (the plural of phylum) forms a Kingdom.
Pieridae - a family of butterflies. This family includes the sulphurs and whites. There are over 1,000 species worldwide.
Pinaculum - are dark, flattened plates on a caterpillar's body that bear the setae (tactile hairs).
Predator - an animal that attacks and eats other animals. Birds are predators; many eat butterflies and moths.
Prepupa - the last larval instar of an insect after it stops eating. During this period, the insect is resting and looks shriveled up and may even appear to be dead.
Prey - an animal is prey when another animal hunts and kills it for food.
Proboscis - a straw like, flexible tongue that uncoils when the butterfly sips liquid food and then coils up again into a spiral when the butterfly is not feeding.
Proleg - a fleshy leg or "false leg" attached to the abdomen of certain insect larvae.
Puddling - sipping nutrient - rich water from puddles. Generally more males than females puddle and it is believed that the salts and nutrients in the puddles are needed for successful mating.
Pupa - the stage in a butterfly's (or moth's) life when it is encased in a chrysalis and undergoing metamorphosis. It does not eat during this stage. It is outwardly inactive, but a lot is going on inside; the caterpillar is changing into a butterfly. The pupa stage lasts from a few days to many months (some butterflies overwinter in the pupa stage, and the adult emerges in the spring).
Pupate - To turn into and exist as a pupa.
Rabble - a group of butterflies. Another name for a group of butterflies is a swarm.
Rainforests - very dense, relatively warm, wet forests. They are havens for millions of plants and animals, including many butterflies and moths.
Rhabdomes - the photoreceptors of an insect's compound eye. The rhabdome contains light-sensitive cells; when light is focused on the rhabdome (by the lens-cornea), these cells are stimulated and send nerve impulses to the brain.
Riodinidae - (Metalmarks) are butterflies that have small metallic-colored spots and lines on their wings. Tropical species are more brightly colored than species from cooler areas. Metalmarks have long antennae. The forelegs are normal in females, but reduced in the males. Most metalmarks have some type of relationship with ants. Caterpillars are slug-like, short, and often have tubercles with bristles.
Scales - tiny modified hairs which overlap on a butterfly wing. The scales give the butterfly wings their color and beauty.
Scape - the base of an insect's antenna.
Scent Scales - modified wing scales on butterflies and moths that release pheromones. Only males have scent scales. The pheromones attract females of that species. Scent scales are also called androconia.
Sclerites - the individual chitinous plates which make up the exoskeleton of insects (including butterflies and moths).
Segments - the natural sections that insects' bodies are divided into. The abdomen of butterflies and moths have eleven segments (the terminal 2 or 3 segments are fused together).
Setae - tactile setae are long hairs that butterflies and moths use to sense touch. These hairs are attached to nerve cells, and relay information about touch to the insect's brain. Setae grow through holes in the pinaculum of the exoskeleton.
Sexual Dimorphism - is the physical differences between the males and females of a species. Frequently, the male and female butterflies are distinguished by vein width and other characteristics.
Silk Girdle - a silken thread that a caterpillar wraps around its body as a support, attaching the larva to a twig or leaf as it is about to enter the pupa stage.
Simple Eye - an ocellus. Butterfly and moth larvae have simple eyes only; adults have simple eyes plus compound eyes.
Sperm - male reproductive cells (gametes). The sperm can fertilize a female's eggs. In butterflies and moths, sperm are transferred to the female in packets called spermatophores.
Spermatophore - a packet containing sperm that male butterflies and moths transfer to the female during mating.
Spinneret - a tube-like structure on a larva's lower lip (labium) that contains the spinning apparatus (the silk glands) of the larva. The caterpillar draws silk (which is made in the salivary glands) from a tube in the spinaret. The silk dries when exposed to the air. Caterpillars use this silk to support themselves and to make webs and cocoons.
Spiracle - one of an insect's breathing pores. They are usually located on the thorax and abdomen. Caterpillars, butterflies and moths breathe using spiracles.
Stage - one of the distinct periods in a butterfly's life. (Butterflies have four stages: egg, larva, pupa and adult.
Stemma - is a simple eye that only detects light; it does not focus images. It is also called a lateral ocellus. Caterpillars have two pairs of six ocelli on their head.
Stridulation - the noise that some butterflies and moths make by rubbing rasp-like abdominal appendages together. The purpose of this noise is unknown.
Swarm - a group of butterflies. Another name for a group of butterflies is a rabble.
Tactile Setae - long hairs that butterflies and moths use to sense touch. These hairs are attached to nerve cells, and relay information about touch to the insect's brain. Setae grow through holes in the hard, chitinous exoskeleton.
Tarsus - the last segment of a butterfly's (or a moth's) leg. The tarsus has gripping claws and has taste organs, so the insect can grip a flower and determine if it contains a sweet nectar to drink.
Tentacles - some caterpillars have tentacles (also known as filaments) on their bodies. These fleshy appendages provide sensory information for the caterpillar. They are often mistaken for antennae. Monarch caterpillars have two pairs of tentacles.
Thoracic Legs - the three pairs of jointed legs on the thorax (mid region) of a caterpillar. Each of these legs has a grasping hook at the end.
Thorax - the second segment in a butterfly's body, located in the mid - section. Butterfly wings and legs are attached to the thorax.
Toxin - a poison. Some butterflies eat plants that contain toxins in order to poison their predators. Monarchs eat milkweed for its toxic glycosides.
Trachea - tiny tubes that carry air through a butterfly (or moth) body.
Trap Lining - a butterfly behavior in which a butterfly hunts for nectar sources (usually flowers) on a set route every day.
Tubercle - a small, knob-like or rounded protuberance (a short, fat tentacle) that sometimes bears a spine or stores and can release a chemical (like everscible tubercles). Many caterpillars have tubercles. For example, the caterpillars of the Cecropia and Cynthia moths have many tubercles along the body.
Uncus - the hook-shaped, downward-pointing end of the vein on the wing of male butterflies and moths.
Vein - the rib - like tubes that give support to the butterfly wings. (The veins are tubes, mostly filled with air.)
Warning Coloration - the bright, attention-getting coloration that protects an organism from experienced predators (i.e., predators who have previously eaten a similar-looking animal and have gotten sick from it). Both poisonous organisms (like the Monarch butterfly) and its mimics (poisonous or not) are said to have aposematic coloration.
Wings - butterflies and moths have four wings. The wings are made of two chitonous layers (membranes) that are nourished and supported by tubular veins.
Wingspan - the distance measured across a butterfly's (or moth's) wings.
Generic Epithet – The first word of a scientific name, which describes the genus the organism belongs to.
Specific Epithet – The second word of a scientific name in binomial nomenclature, describing the species.
Systematics – The evolutionary classification of organisms, which uses binomial nomenclature as its base.
Taxon – A category of biological organization, for example, a genus or phylum.
