''Heliconius cydno'', the cydno longwing, is a

nymphalid The Nymphalidae are the largest family of butterflies, with more than 6,000 species distributed throughout most of the world. Belonging to the superfamily Papilionoidea, they are usually medium-sized to large butterflies. Most species have a red ...

butterfly that ranges from Mexico to northern South America. It is typically found in the forest understory and deposits its eggs on a variety of plants of the genus ''

Passiflora ''Passiflora'', known also as the passion flowers or passion vines, is a genus of about 550 species of flowering plants, the type genus of the family Passifloraceae. They are mostly tendril-bearing vines, with some being shrubs or trees. They ...

''. It is a member of the '' Heliconiinae'' subfamily of Central and South America, and it is the only heliconiine that can be considered

oligophagous Oligophagy refers to the eating of only a few specific foods, and to monophagy when restricted to a single food source. The term is usually associated with insect dietary behaviour. ''H. cydno'' is also characterized by

hybridization Hybridization (or hybridisation) may refer to: *Hybridization (biology), the process of combining different varieties of organisms to create a hybrid *Orbital hybridization, in chemistry, the mixing of atomic orbitals into new hybrid orbitals *Nu ...

and Müllerian mimicry. Wing coloration plays a key role in

mate choice Mate choice is one of the primary mechanisms under which evolution can occur. It is characterized by a "selective response by animals to particular stimuli" which can be observed as behavior.Bateson, Paul Patrick Gordon. "Mate Choice." Mate Choic ...

and has further implications in regards to

sympatric speciation Sympatric speciation is the evolution of a new species from a surviving ancestral species while both continue to inhabit the same geographic region. In evolutionary biology and biogeography, sympatric and sympatry are terms referring to organi ...

. Macrolide scent gland extracts and wing-clicking behavior further characterize this species.

Subspecies

Listed alphabetically: * ''H. c. alithea'' Hewitson, 1869 * ''H. c. barinasensis'' Masters, 1973 * ''H. c. chioneus'' Bates, 1864 * ''H. c. cordula'' Neustetter, 1913 * ''H. c. cydnides'' Staudinger, 1885 * ''H. c. cydno'' Doubleday, 1847 * ''H. c. hermogenes'' Hewitson, 1858 * ''H. c. gadouae'' Brown & Fernández, 1985 * ''H. c. galanthus'' Bates, 1864 * ''H. c. lisethae'' Neukirchen, 1995 * ''H. c. pachinus'' Salvin, 1871 * ''H. c. wanningeri'' Neukirchen, 1991 * ''H. c. weymeri'' Staudinger,

897 __NOTOC__ Year 897 ( DCCCXCVII) was a common year starting on Saturday (link will display the full calendar) of the Julian calendar. Events By place Europe * Spring – King Lambert II travels to Rome with his mother, Queen Ageltr ...

/small> * ''H. c. zelinde'' Butler, 1869

Distribution and habitat

''H. cydno'' ranges from southern Mexico to western Ecuador in northern South America.Beltrán, Margarita and Andrew V. Z. Brower. 2008
"''Heliconius cydno'' Doubleday 1847"
''The Tree of Life Web Project''. Retrieved 4 September 2008. ''H. cydno'' is considered to be non-migratory, or sedentary.Brown, K.S. "The Biology of ''Heliconius'' and Related Genera", ''Annual Review of Entomology'' 1981, 26:1, (pg. 427-457). ''H. cydno'' lives in closed-forest habitats, specifically in the forest understories. They live at elevations from sea level to 2000 meters. Their most common host plants are in the genus ''

'',Merrill R.M., Naisbit R.E., Mallet J., Jiggins C.D. "Ecological and genetic factors influencing the transition between host-use strategies in sympatric ''Heliconius'' butterflies", ''Journal of Evolutionary Biology'', 2013, vol. 26 (pg. 1959-1967). and at night, adults roost in twigs or tendrils from two to ten meters above the forest floor. Males generally tend to fly higher than females, who are found lower in the forest understory. Cydno Longwing underside

Host plant

The diet of ''H. cydno'' larva is generalist. ''Passiflora'' are less common in the closed-forest habitats of ''H. cydno'', and thus the species uses a wide selection within the genus. They tend to prefer orange and red flowers. Other species of ''Heliconius'' restrict their diet to a single species of ''Passiflora'', while ''H. cydno'' is oligophagous (feeding on a restricted range of plants). There are records of five species of ''Passiflora'' being utilized by ''H. cydno'', all in the subgenera ''Granadilla'', ''Plectostemma'', or ''Distephana''. Both ''H. cydno'' and ''H. melpomene'' are known to utilize ''Psiguria warcsewiczii'' pollen.

Parental care

Oviposition

Experiments performed pertaining to ''H. cydno''

oviposition The ovipositor is a tube-like organ used by some animals, especially insects, for the laying of eggs. In insects, an ovipositor consists of a maximum of three pairs of appendages. The details and morphology of the ovipositor vary, but typical ...

reveal that they utilize chemoreception, not visual cues, when choosing their egg-laying sites.Khuc, Kim. "''Passiflora'' (Passifloraceae) defenses against ''Heliconius cydno'' (Nymphalidae: Heliconiinae) oviposition". Monteverde Institute, May 2000. ''H. cydno'' oviposition sites are generally the tendrils of their ''Passiflora'' host plants, and eggs are placed singly. While leaf shape experiments and egg mimics do not have significant effects on oviposition, chemical cues from

methanol Methanol (also called methyl alcohol and wood spirit, amongst other names) is an organic chemical and the simplest aliphatic alcohol, with the formula C H3 O H (a methyl group linked to a hydroxyl group, often abbreviated as MeOH). It is a ...

render sites less appealing to ''H. cydno''. Their lack of preference for leaf shape can be attributed to their varied usage of ''Passiflora'' hosts. ''H. cydno'' also does not participate in larval cannibalism, which plays a role in their indifference to egg mimics.

Life cycle

Egg

The eggs of ''H. cydno'' are yellow, 1.1 mm in height and 0.9 mm wide.

Larvae

Heliconius cydno - Tiergarten Schönbrunn

Early

instar An instar (, from the Latin '' īnstar'', "form", "likeness") is a developmental stage of arthropods, such as insects, between each moult (''ecdysis''), until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or ass ...

larvae of this species have a white body and black spines. Mature larvae are characterized by an orange head topped by two black horns 1.2 cm long. Their bodies are brownish pink, with black scoli (spines with multiple points) and black spots. The caterpillars of ''H. cydno'' are known to form small groups, demonstrating social behavior.

Pupae

Pupae of ''H. cydno'' are characterized by antennae, an abdomen with long spines, and a general dark brown color. They have two rectangular gold patches that decorate the

thorax The thorax or chest is a part of the anatomy of humans, mammals, and other tetrapod animals located between the neck and the abdomen. In insects, crustaceans, and the extinct trilobites, the thorax is one of the three main divisions of the cre ...

Adult

Adults have forewings and hindwings which are black with either yellow or white bands/spots. Their hindwings have bars on their ventral surface, distinguishing themselves from mimics. Wing coloration is dependent on location.

Protective coloration and behavior

Müllerian mimicry

''H. cydno'' engages in the predator defense mechanism of Müllerian mimicry with '' H. eleuchia'' (specifically in Ecuador) and '' H. sapho'' by adopting colors that warn a predator of their bad taste, deterring attacks. For instance, ''H. cydno alithea'', which has two potential colorings, mimics ''H. eleuchia'' in its yellow form, and mimics ''H. sapho'' in its white form. In contrast, ''H. cydno'' close relative, ''H. melpomene'', mimics '' H. erato''.Kronforst M. R., Papa R. (2015). "The functional basis of wing patterning in ''Heliconius'' butterflies: The molecules behind mimicry". ''Genetics'', 200, 1–19.

Genetics

Hybridization

It is a species well known and widely researched for its tendency to hybridize with the closely related '' H. melpomene,'' from which it diverged around 1.5 million years ago. They are

sympatric In biology, two related species or populations are considered sympatric when they exist in the same geographic area and thus frequently encounter one another. An initially interbreeding population that splits into two or more distinct species sh ...

for much of the geographic range of ''H. cydno'', from Central America to northern South America, and exhibit a low level of

and

gene flow In population genetics, gene flow (also known as gene migration or geneflow and allele flow) is the transfer of genetic material from one population to another. If the rate of gene flow is high enough, then two populations will have equivalent a ...

in nature.Russell E. Naisbit, Chris D. Jiggins, James Mallet. "Disruptive sexual selection against hybrids contributes to speciation between ''Heliconius cydno'' and ''Heliconius melpomene''". ''Proceedings of the Royal Society of London B''. 2001 268 1849-1854; . Published 7 September 2001. Hybrids between the two species occur at a frequency of less than 0.1%. Their low levels of hybridization can, in part, be attributed to pre-mating isolation, as ''H. melpone'' is found in more open habitats, while ''H. cydno'' lives in a closed-forest environment.Estrada C, Jiggins CD. 2002 "Patterns of pollen feeding and habitat preference among ''Heliconius'' species". ''Ecological Entomology''. 27, 448–456. Studies suggest that changes in host use and mimicry in ''H. melpomene'' and ''H. cydno'' are genetically determined and may contribute to pre-mating isolation. In the past, this likely contributed to speciation. '' H. pachinus'' is also known to hybridize with ''H. melpomene''. The fact that both species hybridize with ''H. melpomene'' is considered significant because ''H. melpomene'' exhibits a distinct pheromonal chemistry and coloring.Schulz, Stefan, et al. "Macrolides from the scent glands of the tropical butterflies ''Heliconius cydno'' and ''Heliconius pachinus''". ''Organic and Bimolecular Chemistry'', 2007. In fact, it has been suggested that wing preference patterns in mating may limit hybridization, a preference which is also known to limit hybridization between ''H. cydno'' and ''H. pachinus'', which is another closely related species. Thus, divergent coloring (and therefore,

mimicry In evolutionary biology, mimicry is an evolved resemblance between an organism and another object, often an organism of another species. Mimicry may evolve between different species, or between individuals of the same species. Often, mimicry f ...

), contributes to

. While hybridization of species is present, there is evidence to suggest that hybrids are less successful in mating than their non-hybrid counterparts. Hybrids will mate with one another; however, their mating success is 50% of that of their parents, demonstrating disruptive sexual selection against these hybrids that helps to maintain the two species as separate, sympatric species.

Color patterns

There are four key loci that affect wing color and pattern in ''H. cydno''. L determines whether a given individual has

melanic The term melanism refers to black pigment and is derived from the gr, μελανός. Melanism is the increased development of the dark-colored pigment melanin in the skin or hair. Pseudomelanism, also called abundism, is another variant of pi ...

scales over their forewing band. The Sb and Yb loci are tightly linked in ''H. cydno'', although the exact distance is not known. The Sb locus controls for the white submarginal band on the hindwing. The

allele An allele (, ; ; modern formation from Greek ἄλλος ''állos'', "other") is a variation of the same sequence of nucleotides at the same place on a long DNA molecule, as described in leading textbooks on genetics and evolution. ::"The chro ...

for the band is recessive. The Yb locus controls for a yellow band on the hindwing. The allele for this yellow band is also

recessive In genetics, dominance is the phenomenon of one variant (allele) of a gene on a chromosome masking or overriding the effect of a different variant of the same gene on the other copy of the chromosome. The first variant is termed dominant and t ...

. The K locus determines whether the medial band on the forewing, dorsally and ventrally, is yellow or white. An additional locus, G, determines the red line located on the forewing, at the base of the costal vein.

Mating

Coloration

It has been determined, based on crosses performed between ''H. cydno'' and ''H. melpomene'', as well as between ''H. cydno'' and ''H. pachinus'', that there are specific linkage groups associated with both male preference and female mating outcome (red verses black in ''cydno''/''melpomene'' crosses and white verses yellow in ''cydno''/''pachinus'' crosses). Strong linkage can be seen between mate preference and dominant wing color at the locus that controls forewing coloration.Merrill, R. M., Van Schooten, B., Scott, J. A., Jiggins, C. D. "Pervasive genetic associations between traits causing reproductive isolation in ''Heliconius'' butterflies". ''Proceedings of the Royal Society B''. 278, 511–518 (2011). This contributes to co-evolution of mimicry and mate preference while maintaining the association of different species.

Iridescence and light polarization

Wing

iridescence Iridescence (also known as goniochromism) is the phenomenon of certain surfaces that appear to gradually change color as the angle of view or the angle of illumination changes. Examples of iridescence include soap bubbles, feathers, butterfl ...

is another factor in ''H. cydno'' mating. ''Heliconius'' butterflies in general use thin-film iridescence and

polarized light Polarization (also polarisation) is a property applying to transverse waves that specifies the geometrical orientation of the oscillations. In a transverse wave, the direction of the oscillation is perpendicular to the direction of motion of the ...

for mate recognition. ''H. cydno'' has blue iridescence which, at some angles, is 90% polarized. In experiments investigating polarized light as a signal in mating, it was found that when a female's wings were shown behind a depolarizing filter, she was approached at a significantly lower rate than when her wings were shown behind a non-depolarizing filter. It has been suggested that the high degree of iridescence displayed by ''H. cydno'' can be attributed to their forest understory habitat, which generally has less-direct sunlight.Sweeney A, Jiggins C, Johnsen S (2003) "Polarized light as a butterfly mating signal". ''Nature'' 423:31–32.

Multiple matings

''H. cydno'' females are known to mate multiply, thus engaging in

polyandry Polyandry (; ) is a form of polygamy in which a woman takes two or more husbands at the same time. Polyandry is contrasted with polygyny, involving one male and two or more females. If a marriage involves a plural number of "husbands and wives" ...

. There are many possible benefits to females mating multiply that may conclude more robust progeny, more allocation of resources, or other benefits.

Physiology

Macrolide scent gland extracts

Research done on ''H. cydno'' in Costa Rica suggests that the species has 12- and 14-membered macrolide scent gland extracts which have a C-18 skeleton. They are derived from linolenic, linoleic, and

oleic Oleic acid is a fatty acid that occurs naturally in various animal and vegetable fats and oils. It is an odorless, colorless oil, although commercial samples may be yellowish. In chemical terms, oleic acid is classified as a monounsaturated omega ...

acids and have an S configuration. According to the study, other species' desire and ability to hybridize with ''H. cydno'' was not affected by their possession of macrolide scent gland extracts.

Social behavior

In an experiment by Mirian Medina Hay-Roe and Richard W. Mankin, field-collected ''H. cydno'' females were found to produce wing clicks when interacting with members of the same species. Wing clicks are made in short sequences of three to ten clicks, at a speed of approximately ten clicks per second. They demonstrated this behavior during the day and at roosting time, when individuals came close to one another so as to almost touch one another's head or wings. This behavior was also observed during aggressive interactions with ''H. erato'' females. When an experimental group of ''H. cydno'' were moved to a greenhouse and allowed to reproduce, the first generation of adults born in the greenhouses did not demonstrate wing-clicking behavior. The frequency of wing clicking peaked at 1075 Hz, which is close to the 1200-Hz frequency peak of auditory sensitivity in ''H. erato''. This further suggests that communication both between and within species may be facilitated through this behavior.R.W. Mankin, MM Hay-Roe, "Wing-click sounds of ''Heliconius cydno alithea'' (Nymphalidae: Heliconiinae) butterflies", ''Journal of Insect Behavior'', vol. 17, no. 3, pp. 664-674, 2004.

References

{{Taxonbar, from=Q2711578 cydno Butterflies described in 1847