Home All-America Lists Papilionidae Pieridae Lycaenidae DONATE Riodinidae Nymphalidae Hesperiidae All families
Intro Cautions Glossary Biblio Library Links Know-how Catalogue β version - report errors BoA NA List Photo credits Credits Cite Contact © Volunteer

Glossary of acronyms used on this website:

Acronym Institution Name and Location (see more museum name abbreviations here)
[AMNH] American Museum of Natural History (New York, NY, USA)
[ANSP] Academy of Natural Sciences of Drexel University (Philadelphia, PA, USA)
[BMNH] Natural History Museum, London (London, Great Britain)
[CMNH] Carnegie Museum of Natural History (Pittsburgh, PA, USA)
[CSU] Gillette Museum of Arthropod Diversity, Colorado State University (Fort Collins, Colorado, USA)
[IBUNAM] Instituto de Biología, Universidad Nacional Autónoma de México (Mexico City, Mexico)
[INBIO] Instituto Nacional de Biodiversidad (Santo Domingo de Heredia, Costa Rica)
[LACM] Los Angeles County Museum of Natural History (Los Angeles, CA, USA)
[MCZ] Museum of Comparative Zoology, Harvard University (Cambridge, MA, USA)
[MGCL] McGuire Center for Lepidoptera and Biodiversity, Florida Museum of Natural History, University of Florida, (Gainesville, FL, USA)
[MEM] Mississippi Entomological Museum, Mississippi State University (Mississippi State, MS, USA)
[MNHN] Muséum National d’Histoire Naturelle (Paris, France)
[MNHU] Museum für Naturkunde der Humboldt Universität (Berlin, Germany)
[MUSM] Universidad Nacional Mayor de San Marcos, Museo de Historia Natural (Lima, Peru)
[MZFC] Museo de Zoología, Facultad de Ciencias, Universidad Nacional Autónoma de México (Mexico City, Mexico)
[SDMNH] San Diego Museum of Natural History (San Diego, CA, USA)
[USNM] United States National Museum [of Natural History], Smithsonian Institution (Washington, DC, USA)
[ZMHB] Museum für Naturkunde (Berlin, Germany)
Glossary of Butterfly Terms
compiled by Ken Kertell
with assistance from J. P. Pelham, A. D. Warren, N. V. Grishin, J. A. Scott
(see another glossary here)

Jump to terms that begin with the letter:



The last body section, behind the thorax.


An abnormal phenotype, usually in wing pattern or color, which may be caused by genetic, environmental, or developmental factors (14).


A feature of an organism that evolved by natural selection because it performed a certain function better than its antecedents (20). See “natural selection”.

Adaptive radiation

The production of several or many new species from a common ancestor, usually when the ancestor invades a new and empty habitat (20). The radiation is “adaptive” because the genetic barriers between species arise as by-products of natural selection adapting populations to their environments (20). In the subfamily Pierinae, the shift from Fabales (legumes and allied plants) to Brassicales (crucifers and related plants containing glucosinolates), followed by further shifts from Brassicales to Santalales (‘mistletoes’), has led to adaptive radiation (21).


The breeding, final, and most conspicuous stage of the butterfly life cycle; sometimes called the “imago”. The lifespan of adult butterflies ranges from a few weeks to several months, depending on species and environment (1).


The male intromittent organ (organ specialized to deliver sperm) in butterflies (14).


A large class of secondary plant compounds, many of which are produced by specific plant families or genera and which may be important in host-plant selection by butterflies (14).


Active at different seasons or times (14). Compare "synchronic".


Occurring in different areas. Allopatry is suggested to be the primary means of evolutionary radiation through adaptations to differing conditions or habitats in different areas (1). Compare “sympatric”.


The term may be used to indicate a specimen of opposite sex to the holotype; allotypes have no name-bearing function (9). 


A process (often finger-like) arising from the inner side of the valva.

Anal angle

The area enclosed by the inner and outer margins of the hindwing (17).

Anal fold

A fold on the inner margin of the hindwing (17).


Membranous sheath enclosing the aedeagus.


A modified wing scale on some male butterflies that secretes or disperses pheromones, as in courtship (14). (plural: androconia). Compare “stigma


Consisting of ring-like segments or divisions (usually referring to the antennae). 

Ant-butterfly association

See “myrmecophily”.


Either of two long, filamentous appendages on the insect head (15). (plural: antennae). See Figures "1" and "2" depicting antennae for examples of antennae and descriptive nomenclature.


The area at or near the wing tip, or apex. Compare “basal”.


The hooked extension of the antennal club in hesperiids.


Bright, contrasting colors that advertise the unpalatability of an organism to predators (14). Also known as warning coloration. See "mimicry". 


A small subdivision at the base of the wing cell, or a small window on the upper side of a wing scale (8). (plural: areolae).


Protective resemblance afforded palatable members of a species by their close resemblance to unpalatable individuals (14). See "mimicry".


A line of color that runs from the dorsal to the ventral sides of the caterpillar (the entire distance or only a portion of the distance) (11).

Background extinction

The steady extinction at all geological periods of a certain number of individual species (22). Compare “mass extinction”.


Towards the wing base (14)


The area at or near the wing base. Compare “apical”.


A thermoregulatory activity where butterfly species orient themselves to gather incoming solar radiation, usually more common in the cooler hours of the morning. 

Batesian mimicry

The mimicry of an unpalatable species (model) by a palatable one (mimic) (14). Compare "Mullerian mimicry".


Having a two-year cycle.

Bird-butterfly association

An association observed in the Central and South America tropics where many hesperiids (skippers) and some ithomiines (tiger-mimics, glasswings) feed on the liquefied droppings of certain species of antbirds (Formicariidae) and woodcreepers (Dendrocolaptidae) attracted to army ant swarms (Formicidae: Ecitoninae) (19)


Having two flights per year (14).


A single generation of a population during which the adults emerge more or less synchronously (16).

Bursa copulatrix

Internal female copulatory duct, consisting of the ductus bursae and corpus bursae (7). A sac in the female abdomen wherein the spermatophore is stored and digested (after the sperm are released) (15).


A class of secondary plant compounds found mostly in the milkweed and dogbane families, involved in host selection by species feeding on these plants and commonly sequestered by them for their own defense against predators (14). Also called cardiac glycosides (14).


The worm-like, juvenile stage (between egg and pupa) of butterflies and moths; also called the larva. See Figures "1" and "2" depicting larvae for examples of caterpillars and descriptive nomenclature.


Any area of the wing surrounded by veins (3); however, the word “cell” used alone often refers to the discal cell (15). Most cells (other than the discal cell) are labeled according to the vein in front of them, e.g., cell M2 is behind vein M2 (15). See “discal cell”. 

Cervical shield

A heavily pigmented, sclerotized area behind the head of many caterpillars, especially hesperiids (14).


A "V" shaped mark on a caterpillar (11).


The eggshell, often ornately sculptured (14).


The hard case in which a caterpillar transforms into an adult (11); also known as a pupa.


Fine hairs along the edges of the wing (8).


The set of all species descended from a single ancestral species.


A methodology in systematics whereby taxa are hierarchically clustered according to inferred relative recency of common ancestry.


A gradual, progressive, usually continual change in physical characteristics over the geographic or altitudinal range of a species.


The thickened terminal section of the antenna. In papilionids the antennae end in a club, while in hesperiids they end in a hooked extension of the club. See “apiculus”. 


The scleritized plate near the bottom front of the head, attached to the labrum below the antennae. 


The parallel evolution of two kinds of organisms that are interdependent, or where at least one depends on the other, and where any change in one will result in an adaptive response in the other (22). A classic example of coevolution is the relationship between butterflies and their larval foodplants (26).


The dorsal plate behind the head of a caterpillar, usually dark in color (11).


A taxon that periodically establishes breeding populations in a region but not usually as permanent breeding residents(1).


A term loosely applied to a local population of butterflies that persists at one location for a number of years (16). An isolated population (15).


Belonging to the same genus.


Belonging to the same species.


The heavily reinforced vein forming the leading edge of the wing (14).

Costal fold

A flap containing scent scales on the leading edge of the forewing in many males and some females (15). 

Costal margin

The area of the wing adjacent to the costa (3).


The first segment of the leg (nearest the body), attached to the thorax (15). (pl. coxae).


A hook-bearing structure at the tail end of a pupa, used to anchor the animal to a silken pad (14).




Active at dusk or dawn, or in dim light.


Tiny hooks on the bottoms of the prolegs of larvae and on the cremasters of pupae, often occurring in species-specific patterns (15).


Concealing coloration or camouflage, which may entail a generalized or highly specific resemblance to the background or to an object of no interest to a visual predator (14).


Pertaining to the wing veins (3).


The distal portion of the male valva or clasper.


Costal vein.


Disco-cellular vein.


A local population of potentially interbreeding individuals (22).


Having a toothed wing margin.


A type of dormancy characterized by developmental arrest (14). True diapause is under hormonal control and not simply in response to environmental conditions (14). Compare "estivation" and “hibernation”.


The occurrence of two distinct forms within the same population. Compare "sexual dimorphism" and "seasonal dimorphism". 


The central portion of the wing from costa to inner margin (17).

Discal cell

The cell that extends roughly from the base to the middle of the wing (15).


Pertaining to the upper surface, visible when the wings are held open (1). 


A mode of thermoregulation in which the wings are opened broadly to incoming solar radiation (14).

Dorsal nectary organ

In the larvae of many species of lycaenids, a gland located in the dorsal region of the 7th abdominal segment producing a sweet substance attractive to ants (17). 

Dyar's law

An empirical generalization in which successive larval instars in Lepidoptera are related by a constant size multiplier, enabling one to use the shed head capsules to determine the number of molts (14).


Molting or shedding by a caterpillar.


The emergence of the adult butterfly from the chrysalis (16).


An ecological "race” of an organism that is distinct from other related taxa because of different ecological or environmental associations, though it may not be taxonomically named(1). See "race".


The initial live stage of insects. Eggs are normally placed by the adult female on suitable plants that can provide nutrition for the developing larvae, although chemical cues can be misinterpreted and eggs are sometimes placed on inappropriate substrates (1)


An organism, population, or species that is restricted to a limited geographic area or type of environment (1) (14).


A caterpillar that feeds internally in a foodplant concealed from most predators (e.g. Megathymus skippers).

Epigamic behavior

See “mate-locating behavior”.


Articulated process on the tibia (unique to Lepidoptera), used to clean the antenna (7).


Dormancy during summer heat or drought. May or may not involve diapause (14). Compare "diapause" and “hibernation”. 


Genetic change in populations, often producing changes in observable traits of organisms over time (20). See “natural selection”.


A caterpillar that feeds externally on a foodplant, either exposed or hidden part-time in a nest.


A taxon having living representatives, or a specimen still in existence (9).


A taxon with no living representatives (9).


No individuals of a taxon survive in a location where they formerly occurred, but the taxon itself is still extant.


The cast skin of a larva (17).


Markings, usually on the surface of the fore- or hindwings, often consisting of two or more concentric circles with a dark center that resemble a mammalian eye. 

F or FW



The nested rank between order and genus in the Linnaean system (1). Six butterfly families are recognized in North and Central America: Papilionidae (swallowtails and parnassians), Pieridae (whites and sulfurs), Lycaenidae (coppers, hairstreaks, and blues; a.k.a. the gossamer-wings), Riodinidae (metalmarks; placed within Lycaenidae by some authors), Nymphalidae (brushfoots, including fritillaries, checkerspots, crescents, admirals, satyrs, and monarchs), and Hesperiidae (skippers) (1).


The third segment of the leg (the first long movable segment), between the trochanter and the tibia (15).


Fleshy appendages on caterpillars (11).


The distal segment of the antennal shaft in insects.


A single generation of adults (15). 

Flight period

The time of year when adults of a given species can be found.


The front pair of wings on an insect (closer to the head). The forewings provide structural support and are the primary mechanisms of lift for flight. Species with pointed forewings are generally faster, more direct fliers, while those with rounded forewings are usually slower and more maneuverable (1).


A broad, informal term referring to various kinds of phenotypic variation, both polymorphic and polyphenic (14).


Caterpillar excrement or droppings.


The area between the eyes on the front of the head, often bearing a hair-like tuft (17).


All the individuals of a single life cycle (from egg to adult) in a single population (15).


The reproductive organs of adult butterflies, located in the terminal abdominal segments. The genitalia are often of diagnostic value in butterfly taxonomy (14). See male genitalia figures "1", "2" and "3" and female genitalia figures "1" and "2" for examples of male and female genitalia and descriptive nomenclature. 


The nested rank between family and species in the Linnaean system (1).

Geographic speciation

Speciation that begins with the geographic isolation of two or more populations, which subsequently develop into species-level taxa.


A silken thread supporting the midsection of a chrysalis (17). Found especially in the papilionids.


A class of secondary plant compounds restricted largely to the mustard family and its close relatives, involved in host selection by the Cabbage White (Pieris rapae) (14). Also known as mustard oil glycosides (14).


A common inclusion-body disease of butterfly larvae (14)


Pertaining to a female butterfly carrying eggs.


A mate-locating behavior where males aggregate in gullies or washes to wait for or search for receptive females (2).


An individual that contains both male and female characteristics; also known as a sexual mosaic. When one side is female and the other male it is known as a bilateral gynandromorph (14).

H or HW


Hair pencils

Hair-like structures on the legs or abdomens of some butterflies (e.g., Danainae) that are believed to aid in the dissemination of pheromones during courtship.


The body fluids ("blood") of insects. Hemolymph does not usually carry oxygen and thus does not have a respiratory pigment like hemoglobin (14).


Winter nest or shelter. 


Dormancy during the winter, which may or may not involve diapause (14). Compare “estivation” and “diapause”.


A mate-locating behavior where males aggregate on hilltops or ridges to wait for or search for receptive females (2).


The rear pair of wings on an insect. The hindwings primarily are used for stability and increased surface area in flight. When butterflies land with their wings closed (and most do), the ventral hindwing is the primary wing surface observed. Some species have complex color patterns and designs on this wing surface, including eyespots and tails that may draw the attention of predators away from more “critical” areas of the body like the head and forewings. These patterns also can serve as important means of species recognition in courtship (demonstrably so in the Lycaeides blues). In others, like Ceryconis wood nymphs, ventral hindwings are cryptic and serve as camouflage (1).


An insect that undergoes complete metamorphosis (egg, larva, pupa, and adult).


The single specimen upon which a new nominal species-group taxon is based in the original publication; a holotype is a specimen with a name-bearing function (9). 


[1] In the family group: each of two or more available names having the same spelling, or differing only in suffix, and denoting different nominal taxa. [2] In the genus group: each of two or more available names having the same spelling, and denoting different nominal taxa. [3] In the species group: each of two or more available specific or subspecific names having the same spelling, and established for different nominal taxa, and either originally (primary homonymy) or subsequently (secondary homonymy) combined with the same generic name (9).


A sweet liquid secreted by some aphids, scale insects, and lycaenid butterfly larvae as a byproduct of their feeding. Also, a sugary exudate that accumulates on the surface of certain cynipid wasp galls. These galls are often actively tended by ants, which collect the honeydew and drive off parasitoids attempting to attack the gall wasp (12). In addition to ants, the honeydew is used as a food source by some adult butterflies, for example Colorado Hairstreak (Hypaurotis crysalus). See also "myrmecophily".

Hyaline spots

Translucent, glass-like spots on the wings of some butterflies (17).

Hybrid zone

An area of overlap between two species or sub-specific types where hybridization takes place. North American admiral butterflies (genus Limenitis) have historically been of interest because hybridization between nominal species is widespread, with perhaps the most dramatic example involving hybridization zones between mimetic (Limenitis arthemis astyanax) and nonmimetic (Limenitis a. arthemis) populations (27).

Imaginal discs

Clusters of embryonic cells that give rise to the structures of the adult during the late larval and pupal stages (14).


See "adult".

Inclusion-body diseases

A group of diseases of certain caterpillars and other insects in which infective virus is shed within characteristic protein crystals ("inclusion bodies") that are very resistant to degradation in the environment (14).

Influx species

In the southwestern U.S. in particular, a species that enters the region annually from other deserts, thornscrub habitats, and mountain ranges in northern Mexico, with the intensity of the influx thought to be related to the strength, time of onset, and duration of the summer rainy season. Many of these visitors breed and comprise a significant or even dominant portion of the summer butterfly fauna, while others find no suitable plants to serve as larval hosts.


Washed or densely shaded with black or gray (14).


The period between larval molts. Most butterfly larvae molt their exoskeleton about 5 times and therefore have 6 instars, but environmental conditions can alter the number (1). 

International Commission of Zoological Nomenclature (ICZN)

The ICZN is an organization that acts as adviser and arbiter for the zoological community by generating and disseminating information on the correct use of the scientific names of animals, and is responsible for producing the International Code of Zoological Nomenclature - a set of rules for the naming of animals and the resolution of nomenclatural problems (9).


Species that invade periodically from an adjacent or distant area.

Johnston's organ

A sensory organ found in the antennal pedicel (second segment) that serves to detect movements or vibrations of the antennal flagellum relative to the rest of the body.


In the male genitalia of most lepidoptera, the sclerite located between the valvae and below the aedeagus; usually serving as a support for the sheath of the aedeagus.

Junior Synonym

Of two synonyms: the later established, or in the case of simultaneous establishment that not given precedence under Article 24 (9).

Labial palp

In adults, either of the paired structures found on each side of the proboscis, between which the proboscis is coiled (3). The labial palps serve a sensory function.

Lamella antevaginalis

In the female genitalia of most lepidoptera, a sclerite located anterior to the copulatory opening.

Lamella postvaginalis

In the female genitalia of most lepidoptera, a sclerite located posterior to the copulatory opening.


(plural: larvae). See "caterpillar".

Larval foodplant

Any plant eaten by larvae and on which the eggs are normally laid (15). Also known as larval hostplant. Foodplant specificity can vary greatly across butterfly species, ranging from only one plant species to dozens of suitable plant species, and can promote speciation between two or more groups of closely related taxa through reproductive isolation (1). Prime examples of this are Euphilotes blue butterflies and some Apodemia metalmarks that almost exclusively use different species or varieties of buckwheats (Eriogonum) (1). 


A mode of thermoregulation in which one side of the body or wing is exposed to incoming solar radiation (14). The wings are closed and the animal leans so that its plane is perpendicular to the sun’s rays (14).


Designated from syntypes as the single name-bearing type specimen subsequent to the establishment of a nominal species or subspecies (9).


A site where males of a species congregate to attract females, or where females are instinctively programmed to seek them (14). Within the lek, males may be territorial (14). Sites where male hairstreaks perch in numbers can fairly be called leks (14).


The order of insects comprising butterflies and moths. The second largest order of animals on earth with about 180,000 described species worldwide, although only 10-15% of Lepidoptera are butterflies (1).


The scientific study of butterflies and moths.


When populations of an organism are found only in small patches, even though those populations may be very abundant or the overall geographic range of the organism is vast. For example, populations of the Arctic Skipperling (Carterocephalus palaemon) are found in very small areas but the species has a circumboreal distribution (1).


Crescent marks usually found along the margin of the wing (8).


“Major” evolutionary change, usually thought of as large changes in body form or the evolution of one type of plant or animal from another type (20). Evolution above the species level (22). Although macroevolution involves a large evolutionary change, it can perhaps best be understood as the sum of many microevolutionary steps over a very large time scale. Compare “microevolution”.


Along the outer edge of the wing.

Mass extinction

The extermination of a large proportion of the biota by a climatic, geological, cosmic, or other environmental event (22). Compare “background extinction”.

Mate-locating behavior

Behavior that functions to bring the sexes together (14); also called epigamic behavior. Most authors divide mate-locating behavior into two main categories relating to the situation in which the sexes meet: "perching" and "patrolling" (2). In this definition, "hilltopping", "gulching", and “treetopping”, for example, are not considered alternatives to patrolling and perching but are seen as systems that reduce the total area where the males may engage in patrolling or perching (2); with small sites called leks by some authors.

Maxillary galea

The two elongated structures that form the proboscis in adult butterflies.  


The waste products of metamorphosis, often red or pink, voided by the recently emerged adult, usually prior to flight (14).

Medial vein

The fourth wing vein and it’s three branches (3).


The area of the wing halfway between the base and the apex (3).


Central transverse line of the basal area (17).


Central transverse line of the wing; bisecting the discal area (17).


A dark or blackish form of a species.


The second (middle) segment of the thorax.


A set of local populations interconnected by occasional exchange of individuals and genes (14).


The third (posterior) segment of the thorax.


“Minor” evolutionary change, such as the change in size or color of a species (20). Evolution at or below the species level (22). Compare “Macroevolution”.


The systematic dispersal of organisms. In butterflies, migrations may be latitudinal, altitudinal, or both and usually have a seasonal component (14). 


The resemblance of two or more unrelated organisms, where there is adaptive benefit to one, both, or all (14). Near the center of its historic range, the Pipevine Swallowtail (Battus philenor) acquires dangerous chemicals from its larval foodplant and is unpalatable and has no mimics, but in the southeastern U.S. (as inferred from genetic studies), it is mimicked by several unrelated butterfly species (1). See "Batesian mimicry" and "Mullerian mimicry".


To shed the larval skin or exoskeleton (11).


A breeding system in which a female mates with only one male.  


Narrowly specialized in larval foodplant choice, feeding on just one family, genus, or species of plants (14).


Any of the individual forms or phenotypes found in a polymorphic species. See “polymorphism”.


A taxon whose description is based solely on morphological data, without the support of genetic or ecological information (1).

Mullerian mimicry

A type of mimicry in which two or more unpalatable species display very similar phenotypes, which allows predators to learn to avoid that particular phenotype (14). Compare “Batesian mimicry”.


Having three or more flights per year (14).


Median vein.


Associating with ants. The larvae of many lyceanids are regularly attended by ants (15). In many cases these associations are mutualistic whereby the butterfly caterpillar secretes nutritious solutions from specialized glands (honey gland or dorsal nectary organ) in exchange for protection from predators and parasites (6). However, some associations between lycaenids and ants are parasitic with the lycaenid caterpillar preying on the ant brood or being fed by ants as nest inquilines (13). 

Name-bearing type

The type genus, type species, holotype, lectotype, series of syntypes (which together constitute the name-bearing type) or neotype that provides the objective standard of reference for the naming of a taxon (9).


Self-perpetuating in a new environment without human assistance (e.g., Cabbage White [Pieris rapae]) (14).

Natural selection

The “nonrandom”, differential reproduction of alleles (a form of a given gene produced by mutation) from one generation to the next (20). Although mutations occur randomly, it is the “nonrandom” filtering of that variation by natural selection that produces adaptations (20). Natural selection requires only that individuals of a species vary genetically in their ability to survive and reproduce in their environment (20).


The act of feeding on the nectar of flowering plants.


The current theory of the process of evolution, combining the Darwinian theory of evolution by natural selection with modern knowledge of genes and chromosomes to explain the source of the genetic variation upon which selection works.


The single specimen designated as the name-bearing type of a nominal species or subspecies when there is a need to define the nominal taxon objectively and no name-bearing type is believed to be extant (9).


The structure made by many caterpillars (consisting of leaves, silk, and/or ground debris) for concealment when not feeding. 

Nominate subspecies

The subspecies containing the type specimen of a species and thus carrying the name of the species, for example, Hesperia colorado colorado (14).


The scaleless area on the tip of the antenna, especially in hesperiids, where scent detectors are common (15).

Nuptial gifts

The term used to describe the nutrients (amino acids, proteins, lipids, hydrocarbons, and water) the male butterfly in some species transfers, including the spermatophore, to the female during mating (5). 

Objective synonym

Each of two or more synonyms that denote nominal taxa with the same name-bearing type(s) (9).


Rounded, without prominences (14).


Moderately specialized in larval foodplant selection, feeding on plants of only a few plant families (14).


Each facet or individual eye in the adult compound eye; also, each eye of the larva (15). (plural: ommatidia).


The rank nested between class and family in the Linnaean system (1). All butterflies and moths are in the order Lepidoptera.


An eversible, fleshy gland on the first thoracic segment of a papilionid caterpillar, which generally produces a defensive secretion that has a pungent odor. (plural: osmeteria).

Overwintering stage

The stage (egg, larva, pupa, or adult) in which butterflies hibernate through the winter months. Different species hibernate in different stages, and this affects the timing of activity by adults during the warmer months (1).


To lay one or more eggs.


A pair of structures located at the tip of the female abdomen through which eggs are laid.


See "Egg". (plural: ova)


Pertaining to populations and species of such great dispersal capacity that there is complete interbreeding of populations from all parts of their range (22). For example, a widespread Old World butterfly, Lampides boeticus (Lycaenidae), is apparently panmictic with very little genetic variation across large geographic distances (23).


Each specimen of a former syntype series remaining after the designation of a lectotype; paralectotypes have no name-bearing function (9).


An organism that is free-living as an adult but whose larva feed on or in a single host organism. Parasitoids are among the most important natural enemies of butterflies and include many species of small wasps and flies (14).


Each specimen of a type series other than the holotype; paratypes have no name-bearing function (9).

Partial flight

A group of adults that have emerged from pupation while most of their generation remains in diapause (15).


A mate-locating strategy in which male butterflies continuously fly considerable distances to actively seek out receptive females.


Precostal vein.


The second segment of the antennal shaft in insects.


A mate-locating strategy in which male butterflies wait at certain sites for females to arrive, and fly out to investigate passing butterflies to see if they are receptive females.

Pharate adult

The completely developed adult as visible within the pupal case before emergence (14)


The study of the timing (seasonality) of biological events (14). In butterflies this includes the timing of development through metamorphosis, adult flight periods, and breeding through the year (1).


The appearance of an organism, particularly with reference to a particular character (14); examples include the patterns of differently colored scales on the wings of butterflies (1).


A chemical secreted by one organism and that induces specific developmental, physiological, or behavioral changes in another of the same species (14)


The inferred lines of descent of a group of organisms, including a reconstruction of the common ancestor and the amount of divergence of the various branches (22). For an example of how phylogenetic trees are reconstructed see http://butterfliesofamerica.com/knowhow/LBA.htm


A method using genetic data in a geographic context to reconstruct the history and historical distribution patterns of populations (14). Phylogeographic studies suggest that the family Nymphalidae originated in the Cretaceous at 90 million years ago, and that only 10-12 lineages survived the end-Cretaceous mass extinction in the Neotropical and Oriental regions before dispersing widely (24).


A breeding system in which a female mates with more than one male.


A common group of inclusion-body diseases of caterpillars (14). See “inclusion-body diseases”.


The occurrence within a population or species of multiple phenotypes or forms; currently usually restricted to cases where the forms are under direct genetic control (14). This definition excludes seasonal forms. Compare "polyphenism".


The occurrence within a population or species of multiple phenotypes or forms that are induced by environmental influences such as photoperiod or temperature (14). Seasonal forms (e.g., spring vs. summer form, dry season vs. wet season form) in butterflies are polyphenic (14). Compare “polymorphism”.


A group of butterflies belonging to the same species and occupying a defined area(14). Compare "metapopulation". 


That area of the wing that lies just beyond the base (3)

Postdiscal band

The band located between the discal and submarginal areas on the wings of some butterflies (17).


That area of the wing that lies just beyond the median, or central, portion (3).


The inactive stage (last larval instar) when the larva prepares to pupate.

Primary seta

Any of the few hairs (setae) present on nearly all moth and butterfly first-stage larvae.

Principle of Priority

The principle that the valid name of a taxon is the oldest available name applied to it (taking into consideration the other provisions of Article 23), provided that the name is not invalidated by any provision of the Code or by any ruling by the Commission (9).


The feeding tube of adult Lepidoptera, kept coiled beneath the head when not in use (14).


Any of the ten false legs on the posterior segments of a larva (15).


The earlier adult emergence (or arrival) of males than of females (2).


The first (anterior) segment of the thorax.


The pad between the tarsal claws on the leg (3).


The aggregation of butterflies at mud (usually restricted to young males), thought to represent a method of harvesting mineral salts for physiological use (14). 


(plural: pupae). See "Chrysalis" also see pupa illustration.

Pupal mating

A strategy in which males locate clutches of pupae, inspect them for several days, eventually compete for a position on one of the pupae, and mate with the emerging female (4).


To transform into a pupa or chrysalis (18).


An informal term, not recognized in taxonomy, for subdivisions of a species recognizable on phenotypic, ecological, or similar bases (14), generally used for a geographic subspecies.

Radial veins

Wing veins that terminate in the apical area (3).


The geographic area occupied by a species or subspecies. 

Rejection behavior

A behavior performed by an unreceptive female (or male) to discourage a male. These behaviors may include movements (like wing fluttering or vertical then quick downward flights), or postures (like raising the abdomen up between the wings so that the male cannot make genital contact (14, 15). 


A species or population "left behind" in an area during an episode of geologic or climatic change (14); e.g., during a glacial period. Many disjunct populations are relictual (14).

Reproductive isolating barriers

Genetically based features of a species that prevent it from forming fertile hybrids with another species; for example, differences in courtship rituals that prevent out-crossing (20).


A pouch-like expansion located at the base of the valva.


A male mating structure (15).


Very small, flattened modified hairs that cover the wings and bodies of butterflies and moths(1). Colors are produced through chemical pigments, iridescence, or both (1).


The base of the antennal shaft.


Any plate of the hardened (sclerotized) exoskeleton, defined by sutures (7).


Any branching spine or seta-bearing cone on a caterpillar (15), named using B- preceding the name of the nearest primary seta (J. Scott, pers. comm.).

Secondary plant substances

Chemical compounds characteristic of particular plant lineages, generally thought to have defensive functions, and usually important in insect-foodplant relationships (14). Also called secondary plant metabolites (14). As an example, the California Pipevine (Aristolochia californica) plant produces unique chemicals called aristolochic acids (1). The sole butterfly herbivore on this plant in California, the Pipevine Swallowtail (Battus philenor), stores those acids in its body and uses them for its own defense (1).

Secondary seta

Any of the many hairs (setae) that develop as a larva grows from the first stage to maturity.


One of several sections of a caterpillar's abdomen (11), or adult appendages.


A phenotypically distinct population of butterflies that has not been formally described as a subspecies; some segregates will likely be described as subspecies in the future, while some will not.

Selection pressure

Any feature of the environment that results in natural selection; for example, food shortage, the activity of a predator, or competition from other members of the same sex for a mate, can cause individuals of different genetic types to survive to different average ages, to reproduce at different rates, or both.


Having one flight every other year (14).

Senior synonym

Of two synonyms: the earlier established, or in the case of simultaneous establishment that given precedence under Article 24 (9).


Any hair, bristle, or spine projecting from the exoskeleton (does not include the scales). (plural: setae). See “primary seta” and “secondary seta”.

Sexual dimorphism

Conspicuous phenotypic differences between the sexes of a species (14).

Sexual selection

Selection for attributes that enhance reproductive success (22). A form of natural selection (20). In butterflies, for example, intra-specific sexual selection in the Common Eggfly (Hypolimnas bolina) is thought to be the driving force behind the exaggeration of bright, iridescent butterfly color patterns (25).

Sibling species

Species that are so similar phenotypically as to be nearly or quite unrecognizable as such without detailed study; usually first recognized based on behavioral or ecological differences (14).

Sister taxon

The most closely related taxon at the same rank (species, genus, etc.) (1).


The evolution of new populations that are distinct at the species-level. See “geographic speciation”.


Under the biological species concept (which applies only to sexual, out-crossing organisms like butterflies), a group of interbreeding individuals reproductively isolated from other such groups (14).  Many additional species concepts exist, some of which were summarized by Mayden (1997) (28) and Wheeler & Meier (2000) (29).


Rich in number of species, as in the order Lepidoptera.


The organ in the female where sperm can be stored, sometimes for months (14). Once ovulation begins, the sperm leave the spermatheca one at a time and meet the individual eggs as they move down the oviduct (14)


Sperm formation, which in butterflies begins in the late larval stage of males (14)


A sperm-containing package deposited by the male during copulation, usually including nutrients that can be used by the female in making eggs (14). In most butterfly species remnants of the spermatophore (only one is transferred per mating) remain within the female's reproductive tract throughout her lifetime, making it possible to determine the number of times a female has mated by dissecting and counting the number of spermatophore remains (10).

Sperm precedence

A mechanism common in butterflies whereby the most recent male to copulate with the female inactivates any sperm left over from the previous mating (14).


A waxy, vaginal plug formed by a male and inserted into the female during copulation to prevent the female from mating again (14). Found in Parnassians and some Swallowtails (14).


The silk-dispensing lobe beneath the head of a caterpillar (15).


Any of a series of respiratory openings along the sides of the body (15).


Either of the two (or in some skippers any of the four) relatively long spine-like projections on the tibia (15).

Stabilizing (Normalizing) selection

Natural selection that favors “average” individuals in a population over those at the extremes (22).


A pheromone gland on the wings of some male butterflies (14). The stigma is usually located on the dorsal forewing of many hairstreaks (family Lycaenidae) and hesperiids, but may be located on the hindwings or near the body in other butterfly families (1). Also called sex patch.

Stink club

A process at the end of the abdomen of most female Heliconiini, bearing scent scales (15).


Subcostal vein.

Subgenual organ

A sense organ on the tibia that detects substrate vibrations.

Subjective synonym

Each of two or more names whose synonymy is only a matter of individual opinion, i.e. it is not objective (9).


The portion of the wing that lies between the median and postbasal areas (3).


A taxon below the species level that is perceived to have at least some degree of consistent differences phenotypically and with a definite geographic distribution (14). Unlike most species, most subspecies have no "biological" criterion and are often controversial (14). 


An internal ridge of the exoskeleton for strengthening or muscle attachment.


Any visible line or sulcus on the exoskeleton where two segments (sclerites) join.


Occurring in the same area. Compare “allopatric”.


Active at the same times or seasons (14). Compare "allochronic".


Each of two or more names of the same rank used to denote the same taxon (9).


A chronological list or record of the scientific names that have been used to label the same organism.


Each specimen of a type series from which neither a holotype nor a lectotype has been designated (9). The syntypes collectively constitute the name-bearing type (9).


The science involved in the naming of organisms (taxonomy) and the evolutionary and ecological aspects of classification (14).


A projection from the hindwing, well developed in some species (especially Papilionids), or short and slender (as in many hairstreaks) (18)

Tarsal claws

Curved, paired appendages at the end of the last tarsal segment (18).


The tip or last segment of the leg. (plural: tarsi).


A taxonomic unit, whether named or not: i.e. a population, or group of populations of organisms which are usually inferred to be phylogenetically related and which have characters in common which differentiate them (e.g. a geographic population, a genus, a family, an order) from other such units (9). (plural: taxa).


The theory and practice of classifying organisms (9). For the modern (perennially updated) resource on United States and Canada butterfly taxonomy see A Catalog of the Butterflies of the United States and Canada by Jonathan P. Pelham


Either of the two dorsal flaps between the mesothorax and the forewing. 


A butterfly newly emerged from the pupa and not fully hardened and capable of flight (14). 


The part of the insect body (lying between the head and the abdomen) where the legs and/or wings are attached. See “prothorax”, “mesothorax”, and “metathorax”.


The fourth segment of the leg (the second long movable segment), between the femur and tarsus (15). (plural: tibiae).

Tibial tuft

A tuft of hairs (setae) on the tibiae, used in the classification of some duskywings (18). 


A term for a specimen originating from the type locality of the species or subspecies to which it is thought to belong, whether or not the specimen is part of the type series (9).


The junction of the inner and outer margins of the forewing or hindwing. 


The state of inactivity induced by environmental conditions and quickly reversible (14). Also used to refer to the “playing dead” of adult Nymphalis, Polygonia, etc. when handled (J. Scott, pers. comm.).


A mate-locating behavior where males aggregate at treetops (or the tops of shrubs) to wait for or search for receptive females (2).


The second segment of the leg, between the coxa and the femur (15).


Any small, rounded projection on the body of a caterpillar or pupa (11).


A term used alone, or forming part of a compound term, to denote a particular kind of specimen or taxon (9).

Type locality

The geographical place of capture, collection, or observation of the name-bearing type of a nominal species or subspecies (9).

Type series

The series of specimens on which the original author bases a new nominal species-group taxon (9). In the absence of a holotype designation, any such specimen is eligible for subsequent designation as the name-bearing type (lectotype); pending lectotype designation, all the specimens of the type series are syntypes and collectively they constitute the name-bearing type (9). Excluded from the type series are any specimens that the original author expressly excludes or refers to as distinct variants, or doubtfully includes in the taxon (9).

Type species

The nominal species that is the name-bearing type of a nominal genus or subgenus (9).

Type specimen

A term used for a holotype, lectotype or neotype, or for any syntype; also used generally for any specimen of the type series (9).


Underside of wings.


The terminal hook-like structure in the male genitalia (7).

UNF or Unf

Underside of the forewing.

UNH or Unh

Underside of the hindwing.


Having one flight per year (14).


Upperside of wings.

UPF or Upf

Upperside of the forewing.

UPH or Uph

Upperside of the hindwing.


Either of the two appendages at the tip of the male abdomen used to hold the female during mating. Also called clasper. (plural: valvae).


Any of the tubular struts in the insect wing (15).  


The arrangement (pattern) of veins in the insect wing. Wing venation patterns can be key means of identifying taxa (1). See Figures "1", "2", "3", "4" and "5" for examples of how wing veins are labeled.


Pertaining to the under surface. In butterflies, the ventral surface of the wings is visible when the wings are held closed over the body (1).


Basal portion of the male genitalia (7).


The number of flights per year, which usually but not always corresponds to the number of generations (14).

Voucher specimen

A specimen retained as a reference in a study.


Glossary References:


(1) Art Shapiro's Butterfly Site at http://butterfly.ucdavis.edu/glossary

(2) Wiklund, C. 2003. Sexual selection and the evolution of butterfly mating systems. Pp. 67-90 in C.L. Boggs, W.B. Watt, and P.R. Ehrlich, eds, Butterflies: Ecology and evolution take flight. The University of Chicago Press

(3) Opler, P. 1998. A field guide to eastern butterflies. Houghton Mifflin Company, New York.

(4) Deinert, E. I. 2003. Mate location and competition for mates in a pupal mating butterfly. Pp. 91-108 in C.L. Boggs, W.B. Watt, and P.R. Ehrlich, eds. Butterflies: Ecology and evolution take flight. The University of Chicago Press

(5) Karlsson, B. 1998. Nuptial gifts, resource budgets, and reproductive output in a polyandrous butterfly. Ecology 78:2931-2940

(6) Campbell, D.L. and N.E. Pierce. 2003. Phylogenetic relationships of the Riodinidae: Implications for the evolution of ant association. Pp. 395-408 in C.L. Boggs, W.B. Watt, and P.R. Ehrlich, eds. Butterflies: Ecology and evolution take flight. The University of Chicago Press

(7) Powell, J.A. and P.A. Opler. 2009. Moths of Western North America. University of California Press, Berkeley

(8) Wikipedia http://en.wikipedia.org/wiki/Glossary_of_Lepidopteran_terms

(9) International Commission on Zoological Nomenclature, International Code of Zoological Nomenclature, Fourth Edition. Available at http://www.nhm.ac.uk/hosted-sites/iczn/code/

(10) Wedell, N., C. Wiklund, and P.A. Cook. 2002. Monandry and polyandry as alternative lifestyles in a butterfly. Behavioral Ecology 13: 450-455

(11) Allen, T.J., J.P. Brock, and J Glassberg. 2005. Caterpillars in the Field and Garden. Oxford University Press

(12) Inouye, B.D. and A.A. Agrawal. 2004. Ant mutualists alter the composition and attack rate of the parasitoid community for the gall wasp Disholcaspis eldoradensis (Cynipidae). Ecological Entomology 29:692-696

(13) Fiedler, K. 2006. Ant-associates of Palaearctic lycaenid butterfly larvae (Hymenoptera: Formicidae; Lepidoptera: Lycaenidae): a review. Myrmecologische Nachrichten 9:77-87

(14) Shapiro, A.M. and T.D. Manolis. 2007. Field guide to the butterflies of the San Francisco Bay and Sacramento Valley regions. University of California Press, Berkeley

(15) Scott, J.A. 1986. The butterflies of North America: A natural history and field guide. Stanford University Press, Stanford, California

(16) Gochfeld, M. and J. Burger. 1997. Butterflies of New Jersey: A guide to their status, distribution, conservation, and appreciation. Rutger's University Press, New Brunswick, New Jersey

(17) Tolman, T. 1997. Butterflies of Britain and Europe. Harper Collins Publishers, New York

(18) Garth, J.S. and J.W. Tilden. 1986. California butterflies. University of California Press, Berkeley


(19) Austin, G.T., J.P. Brock, and O.H.H. Mielke. 1993. Ants, birds, and skippers. Tropical Lepidoptera 4:1-11


(20) Coyne, J.A. 2009. Why Evolution Is True. Penguin Books, New York


(21) Braby, M. F. and J. W. H. Trueman. 2006. Evolution of larval host plant associations and adaptive radiation in pierid butterflies. Journal of Evolutionary Biology 19:1677-1690.


(22) Mayr, E. 2001. What Evolution Is. Basic Books, New York


(23) Lohman, D.J., D. Peggie, N.E. Pierce, and R. Meier. 2008. Phylogeography and genetic diversity of a widespread Old World butterfly, Lampides boeticus (Lepidoptera: Lycaenidae). BMC Evolutionary Biology 8:301. DOI: 10.1186/1471-2148-8-301.


(24) Wahlberg, N., J. Leneveu, U Kodandaramaiah, C. Pena, S. Nylin, A.V.L. Freitas, and A.V.Z. Brower. 2009. Nymphalid butterflies diversity following near demise at the Cretaceous/Tertiary boundary. Proceedings of the Royal Society B 276:4295-4302.


(25) Kemp, D.J. 2007. Female butterflies prefer males bearing bright iridescent ornamentation. Proceedings of the Royal Society B. Published online.


(26) Ehrlich P.R. and P.H. Raven. 1964. Butterflies and plants: A study in coevolution. Evolution 18:586–608.


(27) Mullen, S.P., E.B. Dopman, and R.G. Harrison. 2008. Hybrid One origins, species boundaries, and the evolution of wing-pattern diversity in a polytypic species complex of North American admiral butterflies (Nymphalidae: Limenitis). Evolution. Published online.


(28) Mayden, R. L. 1997. A hierarchy of species concepts: the denouement in the saga of the species problem. Pp. 381-424, in: Claridge, M. F., H. A. Dawah & M. R. Wilson, Eds. Species. The Units of Biodiversity. Chapman & Hall, London.


(29) Wheeler, Q. D. & R. Meier. 2000. Species Concepts and Phylogenetic Theory. A Debate. Columbia University Press, New York. xii + 230pp.



Larva Parts Composite
Image from: Scott, J.A. 1986. The butterflies of North America: A natural history and field guide. Stanford University Press, Stanford, California, pg. 11, fig. 1


Mature Larva Head
Image from: Scott, J.A. 1986. The butterflies of North America: A natural history and field guide. Stanford University Press, Stanford, California, pg. 11, fig. 2


Pupal Structures
Image from: Scott, J.A. 1986. The butterflies of North America: A natural history and field guide. Stanford University Press, Stanford, California, pg. 12, fig. 5 & 6


Adult Head
Image from: Scott, J.A. 1986. The butterflies of North America: A natural history and field guide. Stanford University Press, Stanford, California, pg. 14, fig. 8


Antennae of Adults
Image from: Scott, J.A. 1986. The butterflies of North America: A natural history and field guide. Stanford University Press, Stanford, California, pg. 14, fig. 11


Abdomen & Thorax
Image from: Scott, J.A. 1986. The butterflies of North America: A natural history and field guide. Stanford University Press, Stanford, California, pg. 15, fig. 12


Adult Thorax from Top
Image from: Scott, J.A. 1986. The butterflies of North America: A natural history and field guide. Stanford University Press, Stanford, California, pg. 15, fig. 13


Adult Leg Parts
Image from: Scott, J.A. 1986. The butterflies of North America: A natural history and field guide. Stanford University Press, Stanford, California, pg. 16, fig. 14


Adult Female Abdomen
Image from: Scott, J.A. 1986. The butterflies of North America: A natural history and field guide. Stanford University Press, Stanford, California, pg. 16, fig. 18


Male Reproductive Structures
Image from: Scott, J.A. 1986. The butterflies of North America: A natural history and field guide. Stanford University Press, Stanford, California, pg. 34, fig. 28


Female Reproductive Structures
Image from: Scott, J.A. 1986. The butterflies of North America: A natural history and field guide. Stanford University Press, Stanford, California, pg. 35, fig. 30


Wing Veins
Image from: Scott, J.A. 1986. The butterflies of North America: A natural history and field guide. Stanford University Press, Stanford, California, pg. 146, fig. 53


Megathymus Immature Habits
Image from: Scott, J.A. 1986. The butterflies of North America: A natural history and field guide. Stanford University Press, Stanford, California, pg. 417, fig. 66

Wing venation of Pontia protodice. Image from: Comstock, J. H. 1918. The wings of insects. The Comstock Publishing Company, Ithaca. 430 pp. p. 333, f. 342


Skipper Wing venation and the structure of antenna. Image from: Steinhauser, Stephen Rogers 1981. A revision of the proteus group of the genus Urbanus Hübner. Lepidoptera: Hesperiidae. Bulletin of the Allyn Museum 62: 1-41, 61 figs. (4 September). f. 1


Grass and Giant Skipper wing venation. Illustrated using Megathymus cofaqui, FLORIDA: Levy Co. Veins names are shown in black, Cell names are shown in white. Image © Nick V. Grishin.


Skipper wing venation in British system. Image from: Evans, William Harry 1949. A catalogue of the Hesperiidae from Europe Asia and Australia in the British Museum (Natural History) xix + 502 pp.


Male genitalia. We do not know the source of this image. Please inform us if you do. TIA.


Structure of a valva in Urbanus and related skippers. Right valva, interior surface, view from the side. Iamge from: Steinhauser, Stephen Rogers 1981. A revision of the proteus group of the genus Urbanus Hübner. Lepidoptera: Hesperiidae. Bulletin of the Allyn Museum 62: 1-41, 61 figs. (4 September). f. 2


Female genitalia of Urbanus and related skippers. View from below. Image from: Steinhauser, Stephen Rogers 1981. A revision of the proteus group of the genus Urbanus Hübner. Lepidoptera: Hesperiidae. Bulletin of the Allyn Museum 62: 1-41, 61 figs. (4 September). f. 3


This website is supported by Butterflies of America Foundation, a U.S. registered 501(c)(3) tax-deductible nonprofit 170(b)(1)(A)(vi) public charity.