Cydno longwing | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Class: | Insecta |
Order: | Lepidoptera |
Family: | Nymphalidae |
Genus: | Heliconius |
Species: | H. cydno |
Binomial name | |
Heliconius cydno (Doubleday 1847) | |
Subspecies | |
See text |
Heliconius cydno, the cydno longwing, is a nymphalid 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 . [1] [2] It is a member of the Heliconiinae subfamily of Central and South America, and it is the only heliconiine that can be considered oligophagous. [3] H. cydno is also characterized by hybridization and Müllerian mimicry. [1] Wing coloration plays a key role in mate choice and has further implications in regards to sympatric speciation. [4] [5] Macrolide scent gland extracts and wing-clicking behavior further characterize this species. [6] [7]
Listed alphabetically: [8]
H. cydno ranges from southern Mexico to western Ecuador in northern South America. [1] H. cydno is considered to be non-migratory, or sedentary. [2] H. cydno lives in closed-forest habitats, specifically in the forest understories. [2] They live at elevations from sea level to 2000 meters. [1] Their most common host plants are in the genus Passiflora , [3] and at night, adults roost in twigs or tendrils from two to ten meters above the forest floor. [1] Males generally tend to fly higher than females, who are found lower in the forest understory. [9]
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. [3] They tend to prefer orange and red flowers. [1]
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. [3] Both H. cydno and H. melpomene are known to utilize Psiguria warcsewiczii pollen. [10]
Experiments performed pertaining to H. cydno oviposition reveal that they utilize chemoreception, not visual cues, when choosing their egg-laying sites. [11] H. cydno's oviposition sites are generally the tendrils of their Passiflora host plants, and eggs are placed singly. [1]
While leaf shape experiments and egg mimics do not have significant effects on oviposition, chemical cues from methanol 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. [11]
The eggs of H. cydno are yellow, 1.1 mm in height and 0.9 mm wide. [1]
Early instar 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. [1]
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. [1]
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. [1]
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. [1] 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's close relative, H. melpomene, mimics H. erato . [4]
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. [1] [10] They are sympatric for much of the geographic range of H. cydno, from Central America to northern South America, and exhibit a low level of hybridization and gene flow in nature. [12] Hybrids between the two species occur at a frequency of less than 0.1%. [12] 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. [10] 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. [3] [10] H. pachinus is also known to hybridize with H. melpomene. [12] The fact that both species hybridize with H. melpomene is considered significant because H. melpomene exhibits a distinct pheromonal chemistry and coloring. [6]
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), contributes to sympatric speciation. [4]
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. [12]
There are four key loci that affect wing color and pattern in H. cydno. L determines whether a given individual has melanic 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 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. 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. [13]
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). [4] Strong linkage can be seen between mate preference and dominant wing color at the locus that controls forewing coloration. [5] This contributes to co-evolution of mimicry and mate preference while maintaining the association of different species.
Wing iridescence is another factor in H. cydno mating. Heliconius butterflies in general use thin-film iridescence and polarized light 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. [14]
H. cydno females are known to mate multiply, thus engaging in polyandry. There are many possible benefits to females mating multiply that may conclude more robust progeny, more allocation of resources, or other benefits.
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 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. [6]
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. [7]
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.
The Heliconiinae, commonly called heliconians or longwings, are a subfamily of the brush-footed butterflies. They can be divided into 45–50 genera and were sometimes treated as a separate family Heliconiidae within the Papilionoidea. The colouration is predominantly reddish and black, and though of varying wing shape, the forewings are always elongated tipwards, hence the common name.
In evolutionary biology, disruptive selection, also called diversifying selection, describes changes in population genetics in which extreme values for a trait are favored over intermediate values. In this case, the variance of the trait increases and the population is divided into two distinct groups. In this more individuals acquire peripheral character value at both ends of the distribution curve.
The viceroy is a North American butterfly. It was long thought to be a Batesian mimic of the monarch butterfly, but since the viceroy is also distasteful to predators, it is now considered a Müllerian mimic instead.
Heliconius charithonia, the zebra longwing or zebra heliconian, is a species of butterfly belonging to the subfamily Heliconiinae of the family Nymphalidae. It was first described by Carl Linnaeus in his 1767 12th edition of Systema Naturae. The boldly striped black and white wing pattern is aposematic, warning off predators. It is the state butterfly of Florida.
Müllerian mimicry is a natural phenomenon in which two or more well-defended species, often foul-tasting and sharing common predators, have come to mimic each other's honest warning signals, to their mutual benefit. The benefit to Müllerian mimics is that predators only need one unpleasant encounter with one member of a set of Müllerian mimics, and thereafter avoid all similar coloration, whether or not it belongs to the same species as the initial encounter. It is named after the German naturalist Fritz Müller, who first proposed the concept in 1878, supporting his theory with the first mathematical model of frequency-dependent selection, one of the first such models anywhere in biology.
Limenitis arthemis, the red-spotted purple or white admiral, is a North American butterfly species in the cosmopolitan genus Limenitis. It has been studied for its evolution of mimicry, and for the several stable hybrid wing patterns within this nominal species; it is one of the most dramatic examples of hybridization between non-mimetic and mimetic populations.
Introgression, also known as introgressive hybridization, in genetics is the transfer of genetic material from one species into the gene pool of another by the repeated backcrossing of an interspecific hybrid with one of its parent species. Introgression is a long-term process, even when artificial; it may take many hybrid generations before significant backcrossing occurs. This process is distinct from most forms of gene flow in that it occurs between two populations of different species, rather than two populations of the same species.
Heliconius erato, or the red postman, is one of about 40 neotropical species of butterfly belonging to the genus Heliconius. It is also commonly known as the small postman, the red passion flower butterfly, or the crimson-patched longwing. It was described by Carl Linnaeus in his 1758 10th edition of Systema Naturae.
Heliconius comprises a colorful and widespread genus of brush-footed butterflies commonly known as the longwings or heliconians. This genus is distributed throughout the tropical and subtropical regions of the New World, from South America as far north as the southern United States. The larvae of these butterflies eat passion flower vines (Passifloraceae). Adults exhibit bright wing color patterns which signal their distastefulness to potential predators.
Heliconius melpomene, the postman butterfly, common postman or simply postman, is a brightly colored, geographically variable butterfly species found throughout Central and South America. It was first described by Carl Linnaeus in his 1758 10th edition of Systema Naturae. Its coloration coevolved with another member of the genus, H. erato as a warning to predators of its inedibility; this is an example of Müllerian mimicry. H. melpomene was one of the first butterfly species observed to forage for pollen, a behavior that is common in other insect groups but rare in butterflies. Because of the recent rapid evolutionary radiation of the genus Heliconius and overlapping of its habitat with other related species, H. melpomene has been the subject of extensive study on speciation and hybridization. These hybrids tend to have low fitness as they look different from the original species and no longer exhibit Müllerian mimicry.
Heliconius ismenius, the Ismenius tiger or tiger heliconian, is a butterfly of the family Nymphalidae found in Central America and northern South America. They are abundant as far south as Ecuador and Venezuela and as far north as southern Mexico, Guatemala and Belize. H. ismenius are more commonly called the tiger-striped long wing butterfly. H. ismenius's nickname is derived from its long wing structure as well as the beautiful burnt orange and black stripes. Pierre André Latreille, a French zoologist, described Heliconius ismenius in 1817. H. ismenius resembles a number of other butterflies, an example of Müllerian mimicry.
Heliconius heurippa is a butterfly of the genus Heliconius that is believed by some scientists to be a separate species from—but a hybrid of—the species Heliconius cydno and Heliconius melpomene, making H. heurippa an example of hybrid speciation.
Парусник Дардан, the Saharan swallowtail,African swallowtail, mocker swallowtail or flying handkerchief, is a species of butterfly in the family Papilionidae. The species is broadly distributed throughout Sub-Saharan Africa. The British entomologist E. B. Poulton described it as "the most interesting butterfly in the world".
Heliconius numata, the Numata longwing, is a brush-footed butterfly species belonging to the family Nymphalidae, subfamily Heliconiinae.
Ecological speciation is a form of speciation arising from reproductive isolation that occurs due to an ecological factor that reduces or eliminates gene flow between two populations of a species. Ecological factors can include changes in the environmental conditions in which a species experiences, such as behavioral changes involving predation, predator avoidance, pollinator attraction, and foraging; as well as changes in mate choice due to sexual selection or communication systems. Ecologically-driven reproductive isolation under divergent natural selection leads to the formation of new species. This has been documented in many cases in nature and has been a major focus of research on speciation for the past few decades.
Heliconius sapho, the Sapho longwing, is a butterfly of the family Nymphalidae. It was described by Dru Drury in 1782. It is found from Mexico southward to Ecuador.
Heliconius eleuchia, the white-edged longwing, is a species of Heliconius butterfly described by William Chapman Hewitson in 1853.
Reinforcement is a process within speciation where natural selection increases the reproductive isolation between two populations of species by reducing the production of hybrids. Evidence for speciation by reinforcement has been gathered since the 1990s, and along with data from comparative studies and laboratory experiments, has overcome many of the objections to the theory. Differences in behavior or biology that inhibit formation of hybrid zygotes are termed prezygotic isolation. Reinforcement can be shown to be occurring by measuring the strength of prezygotic isolation in a sympatric population in comparison to an allopatric population of the same species. Comparative studies of this allow for determining large-scale patterns in nature across various taxa. Mating patterns in hybrid zones can also be used to detect reinforcement. Reproductive character displacement is seen as a result of reinforcement, so many of the cases in nature express this pattern in sympatry. Reinforcement's prevalence is unknown, but the patterns of reproductive character displacement are found across numerous taxa, and is considered to be a common occurrence in nature. Studies of reinforcement in nature often prove difficult, as alternative explanations for the detected patterns can be asserted. Nevertheless, empirical evidence exists for reinforcement occurring across various taxa and its role in precipitating speciation is conclusive.
Eukaryote hybrid genomes result from interspecific hybridization, where closely related species mate and produce offspring with admixed genomes. The advent of large-scale genomic sequencing has shown that hybridization is common, and that it may represent an important source of novel variation. Although most interspecific hybrids are sterile or less fit than their parents, some may survive and reproduce, enabling the transfer of adaptive variants across the species boundary, and even result in the formation of novel evolutionary lineages. There are two main variants of hybrid species genomes: allopolyploid, which have one full chromosome set from each parent species, and homoploid, which are a mosaic of the parent species genomes with no increase in chromosome number.