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Sometimes it is difficult understanding the language when describing butterflies, moths, host plants and nectar sources. Interchangeable use can be confusing. Here is a list of terms that you may come across. The first version of this paper was distributed at our Conference in Tauranga, Easter 2009.

Feel free to send suggestions to so we can improve this resource.

abdomen – The third region of the body of a butterfly (or other insect), consisting of ten segments containing the internal organs like digestive, nervous and excretory systems, as well as sexual organs.

aestivate – to pass the summer or dry season in a dormant condition.

amorphous – without a clearly defined shape or form.

anal claspers – hind-most leg-like structures on the caterpillar, used to attach to the silk pad the caterpillar spins at the beginning of the chrysalis stage.

anal prolapse - occurs with monarch caterpillars when the caterpillar's rectum protrudes from its anus leaving a bright green ball. It is fatal.

anal prolegs – an alternative term for the anal claspers.

anal valve – exposed claspers at the end of the abdomen with which the male holds on to the female.

androconium – a specialised microscopic scale on the wings of male butterflies which release pheronomes to attract females of the same species. Plural is androconia. Sometimes referred to as ‘sex glands’.

angiosperm – flowering plant which produces seeds enclosed in fruit. It is the dominant type of plant with over 250 thousand species. Angiosperms evolved 125 million years ago, becoming the dominant plant life around 100 million years ago. Butterflies and moths are important pollinators of these plants.

antennae – often called ‘feelers’, these are a pair of long appendages on the head of the adult butterfly or other insect used for balance and sensing smells. Butterflies have segmented antennae with club-like ends. Moths have feathery antennae. Singular is ‘antenna’.

anthophyta – the largest group of flowering plants, where flowers are used in reproduction.

apex – (plural: apices) outermost tip of the forewing, where the costa meets the termen.

apolysis – the process where the cuticle separates from the epidermis when a larva is moulting. Occurs before ecdysis, when the larva produces enzymes to digest the inner layer of the cuticle, thus separating the outer cuticle from the larva.

aposematic – describes the attention-getting, warning colouration of a distasteful or poisonous animal that makes it easier for predators to learn not to attack it.

areola – small subdivision at the base of the wing cell or a small ‘window’ on the upper side of a wing scale. Plural areolae.

army – group of caterpillars.

arthropod – the group of animals which have exoskeletons made of chitin, segmented bodies and jointed limbs. Insects, arachnids, crustaceans and others are arthropods.

Asclepias – the milkweeds, a genus of herbaceous perennial, dicotyledonous plants from the Americas, with over 140 known species. It previously belonged to the family Asclepiadaceae, but this is now classified as a subfamily Asclepiadoideae of the dogbane family Apocynaceae.

bagmoth – a moth, the larva of which makes tents of silk and bits of leaves. The larva pupates inside the bag. The female cannot fly as it has no wings (nor legs, antennae or eyes). The moths lay their eggs inside the bag.

base – (referring to the wing), that part where the wing is joined to the body of the animal.

basking – butterflies bask in the sun when their body temperature becomes so low that they cannot fly. They may sun themselves on flowers, rocks or warm surfaces (e.g. road) with outstretched wings in order to absorb as much heat as possible.

blues – butterflies belonging to the worldwide family Lycaenidae.

brood – single generation of butterflies living during the same time period.

brushfoot – a butterfly so-named because it has characteristically reduced forelegs giving the appearance of it having only four legs. The two shorter legs have been adapted to taste-test the host plant before laying eggs – if the plant does not ‘measure up’ the female will not leave eggs behind.

Buddleja – often spelled Buddleia, a genus of easy-to-grow flowering plants named after the Rev Adam Buddle, English botanist. It can be referred to as ‘Butterfly Bush’ as it is very attractive to insects with its high nectar content. About 100 species, not all available in NZ, mostly shrubs but a few being trees. Native throughout the warmer parts of the New World from the southern United States south to Chile, and widely in the Old World in Africa and the warmer parts of Asia, but absent as natives from Europe and Australasia. Blossoms are similar to lilac with sweet nectar attracting many species of butterflies, moths and bees. Note: Buddleia davidii is a declared pest plant in some regions of New Zealand – but there are other varieties which are not. Check with your regional council.

butterfly – Lepidoptera species with clubbed antennae. The word butterfly comes from the Middle English word ‘boterflya’ and the Old English word ‘buttorfleoge’.

cardenolides – or cardiac glycoside, a naturally occurring organic compound (steroid) found in plants including Acokanthera, Adonis, Asclepias, Digitalis, Convallaria, Corchorus, Cryptostegia, Euonymus, Gerbera, Gomphocarpus, Nerium and Thevetia spp.

cell – a closed area of an insect wing bounded by veins.

chitin – a tough, colourless ingredient which is the major component of the hard exoskeleton of insects and other arthropods.

chorion – the hard, outer shell which protects the developing larva within the egg.

chrysalis – the pupal stage of a butterfly, when the caterpillar sheds its skin. Derived from the Greek word for ‘gold’.

clasper – appendage on the rear segment of the male butterfly/moth’s abdomen used to hold onto the female’s abdomen during mating.

classification – the grouping of plant and animal species according to their relationships.

cluster – group of monarchs, usually overwintering.

clypeus – the hard plate on the top of an insect’s head, part of its exoskeleton. The butterfly’s labrum or upper lip is at the bottom edge of the clypeus.

cocoon – protective covering made of silk which protects the pupa of a moth and some other insects. It is spun from the head of the caterpillar (spinneret) before pupation.

complete metamorphosis – the complete reorganisation of the tissues of an insect during its life cycle from larva to adult, usually involving the development of legs and wings from tiny clusters of cells previously present in the larva.

compound eye – eyes made up of many hexagonal lens or corneas which focus light from each part of the insect’s field of view.

coremata – organs at the end of the abdomen of male moths which can be everted to emit pheromones.

costa or costal area or costal margin – leading edge of the forewing (the part of the wing closest to the antennae)

cremaster – the stem by which a pupa or chrysalis hangs, at the abdominal or hind end of a pupa. It replaces the anal claspers in attaching the chrysalis to the branch or stem (or wherever the caterpillar chooses to make its chrysalis).

crochet – small hardened hooklike structure on the end of the abdominal prolegs.

cubitus – the fifth major vein in a wing.

cuticle – the exoskeleton of an insect (or other arthropod), consisting largely of chitin, a polymer similar to cellulose but containing nitrogen.

cryptic – (of colour or markings) serving to camouflage an animal in its natural environment.

Danaidae – group of butterflies also called the ‘milkweed butterflies’ (because milkweed such as swan plant is their larval host plant). The monarch is one such Danaidae butterfly.

deadheading – horticultural practice of removing spent flowers from ornamental plants, a widespread form of pruning. Instead of directing energy into seed development the plant will flower much longer in the season.

diapause – period of suspended growth or development at a particular stage in the life cycle of some insects, usually in anticipation of seasonally adverse conditions such as cold. Onset of diapause is stimulated by a change in day length. In the small white butterfly, diapause occurs in the pupal stage. The adults are sexually mature but will not breed. Should not be confused with quiescence and hibernation. Hibernation is exclusively characterised by low body temperatures while diapause features no such characteristic – butterflies are cold-blooded throughout their life.

discal – cell in the middle of a wing that is relatively free of veins. It is bounded by the radial, the cubital and the discocellular veins.

diurnal – most active during the day. Opposite of nocturnal.

dorsal – of, toward, on, in or near the back or upper surface of an organism.

ecdysis –shedding of the cuticle during growth of an insect (or other arthropod) which has become too small. Sometimes called ‘moulting’.

eclose – to emerge from the pupal stage.

egg – caterpillars hatch from eggs.

endemic – found naturally exclusively in the one geographical place.

entomologist – a scientist who studies insects or entomology.

eruciform – having a caterpillar-like shape, i.e. cylindrical with a well-developed head and legs.

exoskeleton – an external skeleton, a tough structural body armour made of chitin. Arthropods such as insects, arachnids and crustaceans have segmented exoskeletons.

exuvia – the name for the caterpillar cuticle after it has been shed during ecdysis.

filament – a tentacle or antenna-like extension on the body, usually on larvae. Monarch caterpillars have two pairs on their body – one pair on either end.

flier – butterfly in flight.

forewings – the two upper wings of flying insects.

frass – caterpillar faeces, on a healthy caterpillar comes in pellet(s).

generalist – a species that can live in many different types of environments, and has a varied diet.

Gomphocarpus – a genus of milkweed, a herbaceous perennial, dicotyledonous plant from the African continent, with over 168 known species. It previously belonged to the family Asclepiadaceae, but this is now classified as a subfamily Asclepiadoideae of the dogbane family Apocynaceae. In NZ we have G. fruticosus (swan plant) and G. physocarpus (giant swan plant).

gravid – a gravid female is carrying many mature eggs in her ovaries, ready for fertilisation and oviposition.

grounder – dead and/or alive butterflies on the ground – must have all body parts present to be included in a count.

habitat – the place where an organism lives.

haemolymph – the circulatory fluid of arthropods, often referred to as the ‘blood’ of insects.

hatch – when the larva (or caterpillar) comes out of the egg.

haustellum – a type of tongue on the adults of some butterfly and moth families used for sucking up liquids, otherwise kept coiled under the head, proboscis.

head – first body region of an insect, bearing the eyes, antennae and proboscis.

hemimetabolous – having incomplete metamorphosis. Metamorphosis has three distinct stages: egg, nymph, and the adult stage, or imago. Hemimetabolous insects go through gradual changes; there is no pupal stage. Also called paurometabolism.

hibernaculum – (plural hibernacula) is a place in which an insect (and other animal life) overwinter – often made from dead leaves and silk, until the animal emerges in the spring.

hibernation – hibernation and diapause are both animal adaptations in response to a harsh environment or climate. However, diapause is usually observed in insects and also during the development stage of an organism (such as an embryo). Hibernation is exclusively characterised by low body temperatures while diapause features no such characteristic.

hindwings – the two wings of flying insects furthest from the head.

holometabolous – having complete metamorphosis. The immature stages (larvae) are markedly different from the adults. Transformation of the larvae into the adult takes place during the resting stage called the pupa.

host plant – a plant or plants on which eggs are laid and on which the caterpillars feed.

imago – fourth and adult stage of an insect, during which it reproduces. Plural is imagines.

indigenous – (or native) species whose presence is the result of only natural phenomena. May be found naturally in more than one geographical region, e.g. yellow admiral butterfly is also found in Australia. An indigenous species is not necessarily endemic.

inner margin – the trailing edge of the hindwing, at the bottom of the insect, i.e. that part nearest the abdomen.

insects – an arthropod class which has six legs. They evolved during the Silurian Period, 438 to 408 million years ago, long before dinosaurs existed. ‘Insect’ means ‘segmented’ in Latin.

instar – a young insect between two ecdyses or moults. A newly-hatched insect is called a first-instar caterpillar. Caterpillars of most butterflies have five or six instars.

introduced – species that is either inadvertently or deliberately brought to NZ by human transport, and has become established here, e.g. cabbage white butterfly, cinnabar moth.

invertebrate – animal that lacks a backbone.

jaws – referred to as mandibles, which in a caterpillar bites off plant material and tears it into small, easily digestible pieces.

joints – located between the butterfly’s leg segments. Joints help the butterfly bend and move its body.

kingdom – life on earth is divided into kingdoms, such as animals (Animalia), plants (Plantae) and fungi. ‘Kingdom’ is the largest grouping of similar organisms; ‘species’ is the smallest.

labial palps – the moustache-like scaly mouthparts of adult butterflies on each side of the proboscis, covered with sensory hairs and scales with which the butterfly tests whether something is good to eat or not.

labium – the lower ‘lip’ of butterflies and moths, below the proboscis.

labrum – the upper ‘lip’ of butterflies and moths, above the proboscis.

larva – caterpillar. The stage before the pupa in the life cycle of an insect. The caterpillar feeds almost constantly, and moults several times as it outgrows its cuticle. Plural is larvae.

Lepidoptera – an order of insects that is characterised by having four large, scaly wings and a spiral proboscis. Both butterflies and moths belong to this order. There are about 150,000 named species of butterflies and moths, but over 87% are moths. NZ has had identified about 1,500 species of moths, but there are more which have not yet been identified.

lepidopterist – a scientist who studies butterflies and moths.

life cycle – butterflies and moths go through four different life stages called the life cycle.

loner – two butterflies adjacent each other, or fewer, with closed wings, not associated with a cluster.

looper – larva (caterpillar) with 3 pairs of thoracic legs and 2 pairs of prolegs on 6th and 10th abdominal segments. See also 'semi-looper'.

Lycaenidae – gossamer winged butterflies, small and some with a tail-like projection at the bottom of the hindwings. Undersides of wings are speckled, caterpillars are slug-like and male butterflies have reduced forelegs. In NZ we have coppers and blues in this family.

mandibles – jaws of the caterpillar with which it bites off plant materials and tears it into small, easily digestible pieces.

margin – edge of a wing the most distant from the body, usually ‘outer margin’.

maxillae – caterpillar’s mouthparts which grasp the food. They have taste cells, which are chemical detectors helping the caterpillar when to eat and not to eat (if the food is not appropriate). In the adult the maxillae are long, forming the proboscis.

meconium – a metabolic waste product from the pupal stage that is expelled through the anal opening of the adult butterfly shortly after emergence. It is red, but is not blood.

media – the fourth major vein in a wing.

metamorphosis – the transformation of an insect during its life cycle. Butterflies undergo ‘complete’ metamorphosis, as averse to incomplete metamorphosis which is where the young develop gradually, appearing similar to the adults and do not undergo a pupal stage.

micropyle – the large depression at the top of a butterfly’s egg. The small pit marks where the sperm entered the egg. While the egg is developing, oxygen enters the egg through the micropyle.

migration – movement of a large group of one species of animal across many miles to avoid adverse conditions.

milkweed – a family of perennial herbs of which there are more than 100 species, native to the American and African continents, containing varying concentrations of toxic chemicals (glycosides). Monarch caterpillars eat milkweed leaves to incorporate the toxins into their bodies in order to poison their predators. Swan plant (Gomphocarpus physocarpus and G. fruticosus) which originate in Africa, are examples of milkweed.

mimicry – when a palatable species resembles an unpalatable or poisonous species, thus gaining protection from predators. In America both the viceroy and the queen butterflies mimic the poisonous monarch.

monophagous – eats only the one plant. Used when describing biocontrol agents (as against oligophagous, eating a small number of related plants).

moth – Lepidoptera with feathered antennae (not clubbed, as butterflies have) and generally dull in colour. Most moths are nocturnal, flying at night, although there are some exceptions.

moult – the process of losing skin or exoskeleton, and growing a larger one to replace it. The final moult is when a caterpillar turns into a pupa, i.e. pupation.

native – (or indigenous) species whose presence is the result of only natural phenomena. May be found naturally in more than one geographical region, e.g. yellow admiral butterfly is also found in Australia. An indigenous species is not necessarily endemic.

nectar – the sweet liquid produced by many flowers. An adult butterfly sips nectar through its proboscis.

nectar plant – A plant on which adult butterflies, moths, bees, etc feed, taking nectar from the flowers.

nettle – flowering plant in the family Urticaceae with stinging hairs. Host plants of admiral butterflies.

nocturnal – most active at night. Opposite of diurnal.

Nymphalidae – huge family of butterflies, containing over 5,000 species divided into many subfamilies. 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'. Monarchs and admirals are members of this family.

Oe – short for Ophryocystis elektroskirrha, see below.

ocelli – small simple eyes of insects. Singular is ocellus.

oligophagous – eats a variety of related plants. Used when describing biocontrol agents (as against monophagous, eating only the target plant.

Ophryocystis elektroskirrhaa parasite which infects monarch butterflies. It was first discovered infecting monarch and queen butterflies in Florida in the late 1960s and has since been found in all other monarch populations worldwide, so is believed to be naturally occurring. Dormant spores occur on the exterior of the cuticles of infected butterflies, sandwiched in between the butterfly’s scales. Through a microscope, they appear as small, brown or black lemon-shaped objects about 1/100th the size of a butterfly scale. Females transfer the parasite to the plant when laying eggs, caterpillars then eat the parasite. Severely infected adults have difficulty emerging from their pupal cases, and can be too weak to cling to their pupal case to fully expand their wings. They either fail to eclose fully or fall to the ground, leading to severe wing deformities and relatively rapid death. More information about it here.

osmeterium (plural: osmeteria) – defensive organ in the first thoracic segment of larvae of Papilionid butterflies (e.g. swallowtail) which secretes  foul-smelling substances, usually forked and everted typically from behind the head.

outer margin – the edge of the wings furthest away from the body of the butterfly. Sometimes referred to as the termen.

overwintering – sometimes referred to as hibernation (although it is not strictly that), a condition in which an animal remains inactive during the winter or is dormant for a period of time.

oviposit – to lay an egg.

oviposition – the act of laying eggs.

ovipositor – an organ at the end of the female’s abdomen through which she deposits her eggs.

ovum – an egg before it has been fertilised (and in insects, before it has been laid).

palp and palpus (plural: palps or palpi) – a jointed sense organ attached in pairs to the mouthparts of butterflies. Covered with sensory hairs and scales. The butterfly uses them to test whether something is food or not.

parasite – an organism (plant or animal) which lives on or inside another organism (the host), obtaining food from it but without usually killing it.

parasitism – a relationship between two organisms in which one (the parasite) obtains food from the other (the host) without normally killing it.

parasitoid – an insect (usually a tiny wasp) that lays its eggs in or on another animal. When the eggs hatch they feed on the tissues of the host, eventually killing it (unlike parasites, which usually do not kill their host). Parasitoids play a key role in the biological control of insect pests.

peristalis – involuntary constriction and relaxation of muscles creating wave-like movements that push contents in a certain direction.

pheromone – chemicals secreted by some animals that cause specific reactions in others of the same species, e.g. to attract a mate.

photoperiod – the period of daylight in every 24 hours, especially in relation to its effects on plants and animals.

Pieridae – a family of butterflies which includes the whites. Over 1,000 species worldwide.

pinaculum – dark, flattened plates on a caterpillar’s body which bear the setae (tactile hairs).

predator – an organism which attacks, kills and eats its host. Many birds are predators of insects.

prepupa – the last larval instar of an insect, after it stops eating. The insect is preparing to pupate and may look shriveled up or dead. Often referred to as a ‘J’ with monarch larvae because of the shape.

prey – an animal is prey when another animal hunts and kills it for food.

proboscis – a tube-like, flexible ‘tongue’ which butterflies and moths use to sip nectar. It coils up when not in use, and uncoils to sip food. When the butterfly emerges from the pupa, the proboscis is at first in two parts.

prolegs (false legs) – stumpy, peg-like structures on the abdomen (hind region) of a caterpillar, and which are not present in the adult butterfly. They have ‘crochets’ or small hooks on them.

prothoracic shield – dorsal portion or plate of the first thoracic segment.

puddling – when a butterfly on the ground sips water rich in nutrients, such as sodium, from mud puddles or drains.

pupa – the third life stage of many insects in which it changes from a larva (caterpillar) to a imago (adult butterfly). This stage is well hidden to avoid predators and the worst of the weather. Different species of butterflies and moths use different methods for pupae placement. Plural ‘pupae’.

pupate – the act of changing from a larva into a pupa.

quiescence – slowing down of activity in cold weather.

rabble – group of butterflies, sometimes referred to as a swarm.

radius – third major vein in a wing.

sap – a fluid found inside a plant containing variable amounts of food and waste materials, inorganic salts, and nitrogenous compounds.

scales – tiny overlapping pieces of chitin on a butterfly or moth’s wing. The scales are outgrowths of the body wall and are modified setae or hairs.

semi-looper – larva (caterpillar) with 3 pairs of thoracic legs and 3 pairs of prolegs on 5th, 6th and 10th abdominal segments. See also 'looper'.

setae – long, stiff hairs or bristles found on some caterpillars, used to sense taste.

sexual dimorphism – the externally visible physical differences between males and females of a species. Frequently, male and female butterflies are distinguished by vein width and other characteristics.

specialist – animals that require very unique resources, such as a very limited diet or need a specific habitat condition to survive.

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 has the spinning apparatus or silk glands of the caterpillar. Silk is made in the salivary glands from a tube in the spinneret, which dries when exposed to air. Caterpillars use this silk to support themselves and to make webs.

spiracle – breathing holes; the openings to an insect’s respiratory system, located on the sides of the thorax and abdomen,  usually one pair per segment. Spiracles are also on the chrysalis and butterfly.

stinging nettle – flowering plant in the family Urticaceae with stinging hairs. Host plants of admiral butterflies.

stridulation – the noise that some butterflies and moths make by rubbing rasp-like abdominal appendages together. The purpose of this noise is unknown.

submarginal and subterminal – parallel to and somewhat inward from the termen or outer margin.

sunner – used to describe a butterfly which is ‘sunning’; the wings are open and the temperature will be in excess of 55 degrees Celsius.

swarm – a group of butterflies, sometimes referred to as a ‘rabble’.

symbiosis – a situation in which two dissimilar organisms live together. There are various types of symbiosis, including mutualism (both organisms benefit), commensalism (one benefits and the other is not affected) and parasitism. Symbiosis is Greek for ‘living together’.

synanthropic – found in the company of humans.

tachinid fly - tachinid flies will lay eggs inside of larvae. They may look much like houseflies but have very stout bristles at the tips of their abdomens. Instead of a healthy butterfly/moth emerging from the pupa, one or more tachinid flies will emerge.

tactile setae – long hairs that butterflies and moths use to sense touch. They are attached to nerve cells and relay information about touch to the insect’s brain. Setae grow through holes in the chitinous exoskeleton.

tagging – a process in which an animal is fitted with a small label bearing a serial number on it, noting where and when the animal was found, and other appropriate information. Scientists later retrieve the animal and can interpret the information obtained, determining where, when, how fast, and how far the animal travelled. This can provide insight as to how fast they travel, how animals navigate during migrations, how they cope with weather variations, how different groups of a species differ, etc.

tarsus – the last part of a leg of a butterfly or moth. Has gripping claws and taste organs so that the insect can grip a flower and determine if it contains nectar. Plural: tarsi.

tentacles – also known as filaments. Flesh appendages provide sensory information for the caterpillar. Often mistaken for antennae.

termen – the edge of the wings furtherest away from the body of the butterfly. Sometimes referred to as the outer margin.

thanatosis – feigning death, which serves as an anti-predator adaptation in many species of butterfly/moth, such as the monarch larva.

thoracic legs – three pairs of jointed legs on the thorax or mid-region of a caterpillar, with a grasping hook at the end.

thorax – the second body region of an insect, and which bears the wings and legs, between the head and the abdomen.

tornus – the corner of a wing where the outer margin meets the inner margin.

tracheae – tiny tubes that carry air through the body of an insect.

true legs – the legs on the thoracic segments of an insect.

tubercle – small, knob-like protuberance that sometimes bears a spine or stores and can release a chemical.

univoltine – producing one brood in a season, and especially a single brood of eggs capable of hibernating.

Urticae – flowering plants in the family Urticaceae. Many species have stinging hairs and may be called nettles or stinging nettles. Urticae are host plants of the admiral butterflies.

veins – rib-like tubes in the wings that provide the framework and bring nourishment to the wings.

ventral – underneath or the underside, the ‘belly’ of an adult or larva. The lower part of the abdomen.

wingspan – the distance between the outer tip (or apex) of the left and right wings on a butterfly or moth.

woolly bear – the hairy caterpillar of any of the Arctiidae species of moths.

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