Detailed explanations of technical terms relating to the study of Lepidoptera.

abdomenThe segmented part of the body behind the thorax, containing the respiratory, digestive and reproductive organs.
aberrationAn individual with abnormal appearance, usually caused by climatic extremes, pathogens, or genetic mutation.
aestivationA state of diapause during periods of heat or drought, such as the dry season in tropical regions. The opposite of hibernation.
anatomyThe study of the internal and external structure of animals.
androconiaSpecialised wing scales in male butterflies, from which pheromones are disseminated to attract or convey chemical messages to females.
antennaeThe pair of segmented sensory organs arising from the heads of insects, used to detect pheromones. Also known as “feelers”.
apexThe tip of the forewing, where the costa and outer margin meet.
aposematicWarning coloration e.g. bright yellow, orange or red, often in association with a black ground colour. Examples include the yellow and black bands on the abdomen of wasps & hornets, and the fiery orange colour of toxic butterflies such as the Monarch Danaus plexippus.
aphytophagousCarnivorous on homopterans – as with some Lycaenidae caterpillars that feed on aphids, coccids, psyllids or membracids.
basalThe area of the wings that is closest to the thorax.
bivoltineHaving 2 generations per year.
broodA single generation of a population. Hence double-brooded refers to a species having 2 generations per year.
calcareousAlkaline soils and rocks, e.g. chalk, limestone.
camouflageA form of concealment in which the subject is similar in colour and pattern to the surface on which it rests, e.g. the Green Hairstreak Callophrys rubi which is similar in colour and texture to living foliage.
cellThe areas of the wings that are enclosed between veins.
chitinThe tough matter which forms the outer casing of the head, thorax, abdomen, legs, antennae etc of an insect.
chrysalisThe third stage of the lifecycle of a butterfly, in which the metamorphosis from caterpillar to adult butterfly takes place.
cladisticsA diagrammatic system of taxonomy based on quantitative analysis of comparative morphological and behavioural data, hostplant usage, DNA analysis etc. This is used to construct tree diagrams ( cladograms ) that deduce and illustrate relationships between taxa.
clineA progressive change in visible characteristics apparent over the range of a species. The 2 extremes of appearance are linked by a series of intermediates.
colonyA locally isolated population of any given subspecies, the result of fragmented distribution in species with critical habitat requirements.
coppicingA method of woodland management whereby trees are cut every 5-15 years just above the base of the trunk. This stimulates the growth of a number of narrow trunks called poles. These are used to manufacture fence posts, or burnt to produce charcoal. Coppicing exposes the ground to sunlight, thereby stimulating the germination of herbaceous plants that are favoured by butterflies as larval foodplants or nectar sources.
costaThe leading edge of the forewing or hindwing.
costal foldA fold in the leading edge of the forewing, which contains androconia. Found in the males of certain Pyrgines e.g. Erynnis tages.
cremasterTiny hooks at the tip of the abdomen of a pupa, used to secure the pupa to a silk pad spun by the caterpillar.
crepuscularThe habit of becoming active in the half light of dusk or dawn, and being quiescent during bright daylight and total darkness.
crypticColoration and patterning which conceals an insect from predators. Examples include camouflage, disguise and disruptive patterning.
desertificationThe gradual conversion of forested land into arid grassland and finally into desert, as a result of climate change and / or destructive use of land.
desiccationExcessive loss of water from plant or animal tissues.
diematicPatterning or posture that simulates the appearance of a predatory or harmful creature, e.g. the “snake-head” marking on the forewing of an Attacus Atlas moth or the “owl-eyes” on the wings of Automeris moths.
diapauseSuspension of activity and development, usually as the result of climatic influence. Examples include hibernation and aestivation.
dimorphismThe occurrence of 2 distinct forms of a species in a given population. Examples include sexual dimorphism ( male and female being markedly different ) and seasonal dimorphism ( dry season and wet season forms being markedly different ).
discalThe central area of the forewing or hindwing.
disguiseA form of concealment in which the subject strongly resembles a naturally occurring object. Examples include the Comma Polygonia c-album which when it’s wings are closed, resembles a dead leaf, and the Buff-tip moth Phalera bucephala which resembles a broken twig.
dispersalExtension of the range of a butterfly beyond it’s local breeding area, caused when females stray away from existing colonies.
disruptive colorationThe breaking up of wing outlines by mottling, marbling or bands of contrasting colours. Birds tend to target butterflies by shape, so any pattern that breaks up the shape into irregular sections will assist the butterfly in evading attention.
diurnalThe habit of becoming active during daylight hours.
DNADeoxyribonucleic acid – the molecules from which chromosomes and genes are constructed.
dorsalThe back of the body, or the upper ( recto ) surface of the wings.
ecologyThe study of relationships and dependencies of animals and plants with each other and the environment.
endemicThe restriction of a taxa to within a limited and well defined area such as an island, mountain range or country beyond which it is absent.
evolutionThe theoretical ability, as postulated by Darwin and others, of a species developing by degrees into a genetically and physically different organism, by a process known as natural selection.
falcateHooked, as in the apex of a Brimstone butterfly’s forewing.
familyAn assemblage of closely related genera.
faunaThe entire range of animal species within a geographical region.
floraThe entire range of plant species within a geographical region.
formAn ecological, seasonal or sexually dimorphic variety of a species or subspecies, e.g. the form valesina is an ecological variety of the female of the Silver-washed Fritillary – Argynnis paphia f. valesina.
genitaliaThe sexual organs. The male equivalent of a penis is called an aedeagus, the female organ is called a bursa copulatrix.
genus ( pl. genera )An assemblage of species that are more closely related to each other than to species in any other genus. In the case of butterflies and moths, all the species within a given genus will share identical wing venation and various other characteristics.
girdleA silk thread around the “waist” of a chrysalis, supporting it’s weight.
gynandromorphA sterile individual which possesses both male and female characteristics. Only obvious in sexually dimorphic species.
habitatA type of environment or life-zone with particular characteristics that have a limiting effect on the biodiversity of the fauna. Examples include calcareous grassland, sub-alpine meadows, and tropical dry forest.
hair pencilA tuft of androconial scales found at the tip of the abdomen of male Danaines and certain moth families.
hibernaculumA “nest” made by larvae, within which they overwinter. Comprised of a tent of leaves held together with strands of silk, or of a more substantial communal web within which a brood of larvae shelter in the early instars.
hibernationThe dormant stage of the lifecycle in which a species passes the winter months. Depending on the species, hibernation can occur in the egg, caterpillar, chrysalis or adult stage of the lifecycle.
honey dewA sugary by-product expelled by the oak aphid Phylloxera quercus, as it sucks protein-rich fluids from oak leaves. Vast quantities of this substance coat the upper surface of oak leaves in mid-summer, and are used as an adult food source by many butterfly species, and also by ants.
honey glandA gland on the backs of Lycaenid larvae which secretes a sugary substance that is attractive to certain ant species that form symbiotic relationships with the relevant butterfly species.
hyalineTranslucent or transparent “windows” that form part of the pattern of a butterfly’s wings. Occurs mainly in tropical Ithomiines ( Glasswings ) and Satyrines ( Cithaerias, Dulcedo, Haetera etc ).
hybridThe progeny that results from the cross-fertilisation of 2 species. Hybrids of either sex are always sterile.
imagoThe final adult stage of an insect.
instarThe stage of a caterpillars development between moults. Depending on the species, a caterpillar can have 4, 5, or 6 instars.
instinctInherited behaviours and responses, as opposed to those that are learnt by individuals during their own lifetimes. Courtship rituals can appear to be intelligent but are merely a series of instinctive responses to specific stimuli. A female for example might settle if showered with pheromones by a male, and the male then has to respond in a particular way which signals the female to initiate the next phase of the ritual, and so on.
intelligenceThe ability of a species to reason and learn, to understand, and profit from experience. Avian predators exhibit intelligence, but there is no evidence that true intelligence occurs in any insect species.
larvaThe second stage in the lifecycle of a butterfly or moth. Also known as a caterpillar. Examples include silkworms, loopers and woolly bears.
lunuleA crescent shaped mark, typically found in a series around the wing margins of Polyommatinae ( Blues ), Melitaeini ( Fritillaries ) etc.
marginThe outer border of the wings.
mark & recaptureA technique used in the study of population dynamics. Butterflies are captured, painted with a unique identification mark, and released. By comparing the percentage of marked / unmarked butterflies captured on successive days, the size of butterfly populations can be estimated. The technique is also used to “tag” butterflies when studying migration.
melanismIncreased development of black pigments on the wings, prevalent when pupae are subjected to abnormally cold climatic conditions. The higher percentage of blackness on the wings increases heat absorption and enables the butterflies to remain active in colder conditions.
metamorphosisThe transformation of a caterpillar into a chrysalis, and the development of the adult butterfly within the chrysalis.
metapopulationA population comprised of a semi-permanent core colony, surrounded by a number of smaller marginal colonies that wax and wane in size, often periodically collapsing, to be later re-colonised from the core colony.
microhabitatA small and well defined sub-habitat e.g. the forest floor within a mid-elevation transitional wet rainforest, or a damp gully at a particular elevation on a grassy mountainside.
migrationThe spontaneous dispersal of a species over long distances in order to seek suitable breeding sites, e.g. the Clouded Yellow migrates from North Africa, across Europe and northwards into Britain. Migration is probably triggered by climatic conditions, length of day, habitat overcrowding, habitat degradation and other unknown factors.
mimicryThe close visual and behavioural resemblance of one species to another, presumed to be an evolutionary development.
mimicry, BatesianSimilarity of appearance between an unpalatable or noxious species ( the model ) and an unrelated palatable species ( the mimic ).
mimicry, MullerianSimilarity of appearance among a group of related or unrelated species that are all unpalatable or toxic to predators. Avian predators associate the patterning of the whole group with the unpleasant experience of tasting just one or two butterflies.
monocotyledonAny flowering plant whose first sprout from the seed has only one leaf, e.g. grasses, sedges, rushes, orchids, palms, bamboo. These are used as larval foodplants of Hesperiinae, Morphinae and Satyrinae.
morphologyThe study of development and change of structure and form.
mud-puddlingThe act of imbibing dissolved mineral salts from damp ground. Almost exclusively confined to male butterflies, which need to replace salts lost during copulation. In some species it may even be necessary for males to acquire these salts prior to copulation.
myrmecophileA species that lives in a dependent, mutually beneficial, or symbiotic relationship with one or more species of ant.
natural selection“Survival of the fittest”. An evolutionary process whereby individuals that exhibit beneficial anatomical or behavioural adaptations pass on their characteristics genetically to subsequent generations. At the same time, less desirable characteristics are gradually eliminated from populations as a result of heavier predation and other environmental factors.
nectaringThe act of feeding on the nectar of flowering herbs, bushes or trees.
neotropicsMexico and all of the countries of Central America and South America.
nocturnalThe habit of becoming active during night time.
nomenclatureThe assignment of scientific names to families, genera and species.
ocellusA rounded spot or marking on the wings, effectively a “false-eye” that may temporarily startle a predator, or divert attack away from the body of the butterfly.
osmateriumA fleshy forked eversible organ located behind the head of caterpillars in the family Papilionidae. It secretes a noxious fluid which deters attacks by parasitic and predatory wasps, ants, and birds.
ovipositTo lay eggs, either singly or in batches.
ovum ( plural ova )Egg. The first stage in the lifecycle of a butterfly.
PalaearcticThe zoogeographical region that comprises of Europe, North Africa, and the temperate and sub-arctic areas of Asia.
palpiThe pair of sensory organs that project from between the antennae of adult butterflies. Used to detect pheromones.
parasiteAn organism which feeds and develops on or within another species, but does not bring about it’s death. An example is Trombidium breei, a mite which parasitises Common Blue butterflies.
parasitoidAn organism which feeds and develops within another species, ultimately leading to it’s death, e.g. the wasp Apanteles glomeratus whose grubs kill vast numbers of larvae of the Large White Pieris brassicae.
patrollingFlying back and forth over a fixed area. Used to describe the flight of males when actively searching for females.
perchingMate location whereby a male waits on a protruding leaf or twig, darting out to intercept and investigate passing insects to seek females. The male nearly always returns to the perch afterwards, and defends the territory by ejecting other males.
pheromoneAn airborne chemical substance disseminated by male butterflies that induces receptiveness or passiveness in females of the same species. Related substances are used by female moths e.g. Saturniidae and Lasiocampidae, to attract male moths from a considerable distance.
phylogeneticsThe study of natural evolutionary relationships between groups of living things, inferred using DNA analysis. The results are usually output as cladistic diagrams ( phylogenetic trees )
pigmentA chemical which in the case of butterflies is derived from the caterpillar’s food plants, and which produces the base colour of individual wing scales.
plantationSecondary forest which has been planted with plots of a single species of tree, typically oak, beech or spruce. The trees are allowed to reach maturity and then felled en masse. Butterfly diversity in such habitats is poor as most species are unable to survive in the cool shady forest. The creation of wide tracks, large semi-permanent glades, enlarged intersections, and scalloping of ride edges are management techniques used to encourage butterflies to breed in such forests.
polymorphismThe occurrence of 2 or more forms of a given species within the same population, as in the Mocker Swallowtail Papilio dardanus.
polyphagousDescribing a species whose larvae feed on a wide range of different plant species from different genera or families. Such highly adaptable species tend to be much more widespread and abundant than those which specialise on particular larval foodplants.
polyvoltineHaving several generations per year. Also univoltine, bivoltine, trivoltine, meaning having one, two or three generations per year.
populationMembers of a species that live together in the same area, and whose subsequent generations maintain uniform genetic character.
proboscisThe tube through which adult butterflies suck liquid foods, and which is coiled between the labial palpi when not in use.
pupa ( pl. pupae )The 3rd stage in the lifecycle of a butterfly in which the bodily tissues are broken down and reform as an adult butterfly. Also known as a chrysalis.
raceA distinctive population which is visually separable from other races of the same species, but which is not sufficiently different to be regarded as a sub-species. Examples include the “Castle Eden Argus” and the “Scotch White-spot”, collectively known as the Northern Brown Argus. Both are races of the sub-species Aricia artaxerxes artaxerxes.
rangeThe entire area within which a species naturally occurs. The distribution of a species within it’s range is often patchy, but in the more adaptable species can be contiguous.
recessiveSuppressed by a corresponding dominant gene, so that the recessive form, which is normally different in appearance, occurs less frequently in the population than the dominant form.
reflectance baskingBasking with the wings held half open, so as to reflect sunlight falling on the wings of whites, blues and coppers onto the thorax and abdomen, to facilitate rapid warming.
reticulationA network pattern.
scalesMicroscopic plates which arise from individual cells on the wings, body and legs of butterflies and moths. The wing scales overlap like the tiles on a roof, and are easily dislodged, appearing as coloured dust on the fingers when butterfly wings are handled. The scales on the body and legs are long and thin, giving the appearance of fur or hair.
speciesA group of individuals that interbreed, producing and maintaining genetically identical fertile healthy offspring over a period of millions of generations. By definition a species cannot interbreed with another taxon to produce fertile offspring.
sphragisA plug or structure which seals the genital opening of fertilised females of certain species, e.g. Parnassius apollo, or Euphydryas aurinia, physically preventing further copulation.
spiraclesA series of breathing holes arranged in a row on each side of the abdominal part of larvae, pupae and adult butterflies.
submarginalThe area slightly inboard of the margins on the wings, often marked with lunules, ocelli or chevrons.
sub-speciesA population that is permanently isolated geographically from other populations of the same species, and which has constant and obvious differences in appearance and ecology compared with other populations of the same species. Sub-species never naturally interbreed, but have the potential to produce fertile offspring if interbred in captivity. The term “subspecies” is regarded as unscientific by some taxonomists who consider “species” to be the terminal taxonomic rank, and “sub-species” to be merely a convenient way of naming geographical races.
symbiosisThe co-existence and inter-dependence of 2 organisms, such that one or both of the organisms is incapable of surviving without the cooperation of the other. The Large Blue Maculinea arion for example is incapable of surviving unless it feeds during it’s larval stage on the grubs of the ant Myrmica sabuleti. The ant benefits from having the larva in it’s nest, but can survive without it.
sympatricOccurring in the same area.
synonymDuplicated scientific names applied to the same taxon. The first published species name is valid. Others are called junior or invalid synonyms. When taxonomists revise the classification of a species it is often transferred to a newly created genus, e.g. the Meadow Brown was originally given the name Papilio jurtina, but is now called Maniola jurtina.
taxon ( pl. taxa )Any scientifically defined biological unit, e.g. the class Insecta, the family Nymphalidae, the genus Apatura, or the species iris.
taxonomyThe scientific classification of organising animals and plants into groups as defined by presumed relationships. Patterns of wing venation for example are commonly used to assign species into appropriate genera.
territoryA fixed area defended by the male of a species, often centred on a perching place such as a particular leaf, which is used as a lookout post from which to survey passing females.
thoraxThe muscular middle section of an insect’s body, which acts as an anchor for the legs, wings, head and abdomen.
transectA regular weekly walk that follows a fixed route through a butterfly habitat. The route is divided into sections, each representing a different sub-habitat. The butterflies seen in each section are counted, and the figures compared to those obtained in other sections, or from the same section in previous years. The figures are analysed to determine the management factors that affect butterfly populations.
tuberclesWart-like nodules which are formed in bands on the abdominal segments of certain species of caterpillar. In some subfamilies e.g. Nymphalinae, the tubercles are greatly enlarged and extended to form rows of branched spines along the back and sides.
univoltineHaving a single generation per year.
varietyAn unscientific term approximately synonymous with “form”.
veinA tubular blood vessel, particularly in reference to the tubes supporting the membrane of butterfly wings.
venationThe pattern and arrangement of veins on the wings.