Speckled wood | |
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Male P. a. tircis | |
Male underside | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Class: | Insecta |
Order: | Lepidoptera |
Family: | Nymphalidae |
Genus: | Pararge |
Species: | P. aegeria |
Binomial name | |
Pararge aegeria | |
The speckled wood (Pararge aegeria) is a butterfly found in and on the borders of woodland areas throughout much of the Palearctic realm. [1] The species is subdivided into multiple subspecies, including Pararge aegeria aegeria, [1] Pararge aegeria tircis, Pararge aegeria oblita, and Pararge aegeria insula. [2] The color of this butterfly varies between subspecies. The existence of these subspecies is due to variation in morphology down a gradient corresponding to a geographic cline. [3] The background of the wings ranges from brown to orange, and the spots are either pale yellow, white, cream, or a tawny orange. The speckled wood feeds on a variety of grass species. [2] The males of this species exhibit two types of mate locating behaviors: territorial defense and patrolling. [4] The proportion of males exhibiting these two strategies changes based on ecological conditions. [4] [5] The monandrous female must choose which type of male can help her reproduce successfully. Her decision is heavily influenced by environmental conditions. [6]
The speckled wood belongs to the genus Pararge , which comprises three species: Pararge aegeria, Pararge xiphia , and Pararge xiphioides . Pararge xiphia occurs on the Atlantic island of Madeira. Pararge xiphioides occurs on the Canary Islands. Molecular studies suggest that the African and Madeiran populations are closely related and distinct from European populations of both subspecies, suggesting that Madeira was colonized from Africa and that the African population has a long history of isolation from European populations. [1] Furthermore, the species Pararge aegeria comprises four subspecies: Pararge aegeria aegeria, Pararge aegeria tircis, [1] Pararge aegeria oblita, and Pararge aegeria insula. [2] These subspecies stem from the fact that the speckled wood butterfly exhibits a cline across their range. This butterfly varies morphologically down the 700 km cline, resulting in the different subspecies corresponding to geographical areas. [3]
The average wingspan of both males and females is 5.1 cm (2 in), although males tend to be slightly smaller than females. Furthermore, males possess a row of grayish-brown scent scales on their forewings that is absent in the females. [2] Females have brighter and more distinct markings than males. The subspecies P. a. tircis is brown with pale yellow or cream spots and darker upperwing eyespots. The subspecies P. a. aegeria has a more orange background and the hindwing underside eyespots are reddish brown rather than black or dark gray. The two forms gradually intergrade into each other. [1] Subspecies P. a. oblita is a darker brown, often approaching black with white rather than cream spots. The underside of its hindwings has a marginal pale purple band and a row of conspicuous white spots. The spots of subspecies P. a. insula are a tawny orange rather than a cream color. The underside of the forewings has patches of pale orange, and the underside of the hindwing has a purple-tinged band. Although there is considerable variation with each subspecies, identification of the different subspecies is manageable. [2]
The morphology of this butterfly varies as a gradient down its geographic cline from north to south. The northern butterflies in this species have a bigger size, adult body mass, and wing area. These measurements decrease as one moves in a southerly direction in the speckled wood's range. Forewing length on the other hand increases moving in a northerly direction. This is due to the fact that in the cooler temperatures of the northern part of this butterfly's range, the butterflies need larger forewings for thermoregulation. Finally, the northern butterflies are darker than their southern counterpart, and there is a coloration gradient, down their geographical cline. [3]
The speckled wood occupies a diversity of grassy, flowery habitats in forest, meadow steppe, woods, and glades. It can also be found in urban areas alongside hedges, in wooded urban parks, and occasionally in gardens. Within its range the speckled wood typically prefers damp areas. [2] It is generally found in woodland areas throughout much of the Palearctic realm. P. a. tircis is found in northern and central Europe, Asia Minor, Syria, Russia, and central Asia, and the P. a. aegeria is found in southwestern Europe and North Africa. [1] Two additional subspecies are found within the British Isles: the Scottish speckled wood (P. a. oblita) is restricted to Scotland and its surrounding isles, and the Isles of Scilly speckled wood (P. a. insula) is found only on the Isles of Scilly. [2] P. a. tircis and P. a. aegeria gradually intergrade into each other. [1]
The eggs are laid on a variety of grass host plants. The caterpillar is green with a short, forked tail, and the chrysalis (pupa) is green or dark brown. The species is able to overwinter in two totally separated developmental stages, as pupae or as half-grown larvae. This leads to a complicated pattern of several adult flights per year. [7]
Larval food plants include a variety of grass species such as Agropyron (Lebanon), Brachypodium (Palaearctic), Brachypodium sylvaticum (British Isles), Bromus (Malta), Cynodon dactylon (Spain), Dactylis glomerata (British Isles, Europe), Elymus repens (Lebanon), Elytrigia repens (Spain), Holcus lanatus (British Isles), Hordeum (Malta), Melica nutans (Finland), Melica uniflora (Europe), Oryzopsis miliacea (Spain), Poa annua (Lebanon), Poa nemoralis (Czechia/Slovakia), Poa trivialis (Czechia/Slovakia), but the preferred species of grass is the couch grass (Elytrigia repens). The adult is nectar feeding. [7]
The growth and development of the speckled wood butterfly is dependent on the larval density and the sex of the individual. High larval densities result in decreased survivorship as well as a longer development and smaller adults. However, females are much more adversely affected by this phenomenon. They depend on their larval food stores during oviposition, so a high larval density in the larva stage can result in lower fecundity for females in the adult stage. Males can compensate for their smaller size by feeding as adults or switching mate-locating tactics, so they are less affected by high larval densities. [8] A high growth rate can also negatively affect larval survivorship. Those with high growth rates will also have high weight-loss rates if food becomes scarce. They are less likely to survive if food becomes available once again. [9]
In the speckled wood butterfly females are monandrous; they typically only mate once within their lifetime. On the other hand, males are polygynous and typically mate multiple times. [10] In order to locate females, males employ one of two strategies: territorial defense and patrolling. [4]
During territorial defense, the male defends a sunny spot in the forest, waiting for females to stop by. Another strategy is patrolling, during which males fly through the forest actively searching for females. [4] Then, the female must make a choice between mating with a patrolling male or a territorial male. By mating with a territorial male, a female can be sure that she has chosen a high quality male, as the ability to defend a territory reflects the genetic quality of a male. Therefore, by choosing a territorial male, the female is being more picky about which male she chooses to mate with. [6]
The choice is most likely dependent on the search costs associated with finding a mate. When actively searching for a male, a female must spend her precious time and energy, which results in search costs, especially when she has a limited life span. As search costs increase, female choosiness for a mate decreases. For example, if a female's life span is shorter, she has a higher cost associated with searching for the ideal mate. Therefore, she is likely to mate within a day of her emergence as an adult, and will most likely mate with a patrolling male, as they are easier to find. However, if a female lifespan is longer, then the search costs associated with finding a mate are lower. The female is then more likely to actively search for a territorial male. Since the search costs vary depending on environmental conditions, strategies vary from population to population. [6]
Males employing different strategies, territorial defense or patrolling, can be differentiated by the number of spots on their hindwings. Those with three spots are more likely to be patrolling males, while those with four spots are more likely to be defending males. The frequency of the two phenotypes depends on the location and time of year. For example, there are more territorial males in areas where there are many sunny spots. Furthermore, the development of wingspots is influenced by environmental conditions. Therefore, the strategy employed by males is heavily dependent on environmental conditions. [4]
Territorial defense involves a male flying or perching in a spot of sunlight that pierces through the forest canopy. The speckled wood butterfly spends the night high up in the trees, and territorial activity commences once sunlight passes through the canopy. The males often remain in the same sunspot until the evening, following the sunspot as it moves across the forest floor. The males often perch on vegetation near the forest floor. If a female flies into the territory, the resident male flies after her, the pair drop to the ground, and copulation follows. If another species flies through the sunspot, the resident male ignores the intruder. [11]
However, if a conspecific, a male of the same species, enters the sunspot, the resident male flies towards the intruder almost bumping into him, and the pair fly upwards. The winner flies back towards the forest floor within the sunspot, while the defeated male flies away from the territory. [11] The pattern of flight during this encounter depends on the vegetation. In an open understory, the pair fly straight upwards. In a dense understory, this flight pattern is not possible, so the pair spiral upwards. [5]
In most of these interactions, the conflict is relatively short, and the resident male wins. The intruder most likely backs down as a serious confrontation could be costly, and there is an abundance of equally desirable sunspots. However, if both males believe they are the "resident" male, the conflict escalates. [11] If a previous owner of the sunspot tries to reclaim his territory after he has left for mating, a longer and more costly fight ensues. In these serious fights, the winner of the contest is not predictable. [5]
The abundance of territorial behavior depends on the environmental conditions. At the beginning of the mating season, fights over ownership of a sunspot territory are lengthy. The duration of the conflict quickly decreases during a period of two weeks. This pattern is correlated with the progression of the season, as temperature and male density rise. Sunspots are more attractive when temperatures are low, as they provide the warmth needed for higher levels of activity. As male density increases, it becomes increasingly difficult to hold onto a territory, so territoriality decreases and more males exhibit patrolling behavior. [5]
In butterflies, asymmetrical wings are observed in three different ways: fluctuating (small, random variations from the standard bilateral symmetry), directional (variations that are biased towards a particular side so one wing is larger than the other), and antisymmetry (similar to directional but half of the individuals of the species find that a particular wing, such as their left, is larger, and the other half of the individuals find that their right is larger. [12]
Both genders of the speckled wood butterfly exhibit asymmetrical wings; however, only males show directional asymmetry (likely to be caused by genetic factors). [12] Also, females show more asymmetry in general compared to males. Within male speckled wood butterflies, the melanic form shows greater directional asymmetry and grows more slowly than the pale, territorial males. Furthermore, males that are most successful in territorial disputes are only slightly asymmetrical, as opposed to complete symmetry or asymmetry; this indicates that sexual selection affects asymmetry. [12]
A female's fecundity is dependent on body mass, as females deprived from sucrose during their oviposition period have reduced fecundity. Therefore, heavier females will produce a larger number of eggs. [13] In addition to body mass, the number of eggs laid by a female may also be related to the time spent searching for an oviposition site. The number of eggs laid is inversely proportional to egg size. However, egg size was not found to have any influence on egg or larval survival, larval development time, or pupal weight under experimental conditions. One explanation may be that there is a tradeoff between the number of eggs laid and the time spent searching for the optimal oviposition site. A female would produce more eggs in an optimal environment, so she can produce more offspring and increase her reproductive fitness. [14]
During copulation in butterfly species, the male deposits a spermatophore in the female consisting of sperm and a secretion high in proteins and lipids. The female uses the nutrients in the spermatophore in egg production. In a polyandrous mating system, where sperm competition is present, it is beneficial for males to deposit a large spermatophore in order to fertilize the largest amount of eggs possible and possibly prevent the female from mating again. [15]
Since most females in the speckled wood butterfly behave monandrously, there is decreased sperm competition, and the male's spermatophore is much smaller relative to other species. [15] The speckled wood male's spermatophore size increases as body mass of the male increases. The spermatophore in the second copulation is significantly smaller, so copulation with a virgin male results in a higher number of larval offspring. Therefore, there is a cost to females associated with mating with a non-virgin male. [10]
Vanessa atalanta, the red admiral or, previously, the red admirable, is a well-characterized, medium-sized butterfly with black wings, red bands, and white spots. It has a wingspan of about 2 inches (5 cm). It was first described by Carl Linnaeus in his 1758 10th edition of Systema Naturae. The red admiral is widely distributed across temperate regions of North Africa, the Americas, Europe, Asia, and the Caribbean. It resides in warmer areas, but migrates north in spring and sometimes again in autumn. Typically found in moist woodlands, the red admiral caterpillar's primary host plant is the stinging nettle ; it can also be found on the false nettle. The adult butterfly drinks from flowering plants like Buddleia and overripe fruit. Red admirals are territorial; females will only mate with males that hold territory. Males with superior flight abilities are more likely to successfully court females. It is known as an unusually calm butterfly, often allowing observation at a very close distance before flying away, also landing on and using humans as perches.
Aglais io, the European peacock, or the peacock butterfly, is a colourful butterfly, found in Europe and temperate Asia as far east as Japan. It was formerly classified as the only member of the genus Inachis. It should not be confused or classified with the "American peacocks" in the genus Anartia; while belonging to the same family as the European peacock, Nymphalidae, the American peacocks are not close relatives of the Eurasian species. The peacock butterfly is resident in much of its range, often wintering in buildings or trees. It therefore often appears quite early in spring. The peacock butterfly has figured in research in which the role of eyespots as an anti-predator mechanism has been investigated. The peacock is expanding its range and is not known to be threatened.
The small tortoiseshell is a colourful Eurasian butterfly in the family Nymphalidae. Adults feed on nectar and may hibernate over winter; in warmer climates they may have two broods in a season. While the dorsal surface of the wings is vividly marked, the ventral surface is drab, providing camouflage. Eggs are laid on the common nettle, on which the larvae feed.
The green-veined white is a butterfly of the family Pieridae.
The small heath is a butterfly species belonging to the family Nymphalidae, classified within the subfamily Satyrinae. It is the smallest butterfly in this subfamily. The small heath is diurnal and flies with a noticeable fluttering flight pattern near the ground. It rests with closed wings when not in flight. It is widespread in colonies throughout the grasslands of Eurasia and north-western Africa, preferring drier habitats than other Coenonympha, such as salt marshes, alpine meadows, wetlands, and grasslands near water. However, habitat loss caused by human activities has led to a decline in populations in some locations.
Gonepteryx rhamni, commonly named the common brimstone, is a butterfly of the family Pieridae. It lives throughout the Palearctic zone and is commonly found across Europe, Asia, and North Africa. Across much of its range, it is the only species of its genus, and is therefore simply known locally as the brimstone. Its wing span size is 60–74 mm (2.4–2.9 in). It should not be confused with the brimstone moth Opisthograptis luteolata.
A spermatophore or sperm ampulla is a capsule or mass containing spermatozoa created by males of various animal species, especially salamanders and arthropods, and transferred in entirety to the female's ovipore during reproduction. Spermatophores may additionally contain nourishment for the female, in which case it is called a nuptial gift, as in the instance of bush crickets. In the case of the toxic moth Utetheisa ornatrix, the spermatophore includes sperm, nutrients, and pyrrolizidine alkaloids which prevent predation because it is poisonous to most organisms. However, in some species such as the Edith's checkerspot butterfly, the "gift" provides little nutrient value. The weight of the spermatophore transferred at mating has little effect on female reproductive output.
The gatekeeper or hedge brown is a species of butterfly found across Europe. Given its preference for warmer weather, the restriction of range expansion can be assumed to be due to climate. Colonies vary in size depending on the available habitat, and can range from a few dozen to several thousand butterflies. Named for its rigorous patrol of hedges and woodland rides, the gatekeeper butterfly is a prime pollinator.
Polygonia c-album, the comma, is a food generalist (polyphagous) butterfly species belonging to the family Nymphalidae. The angular notches on the edges of the forewings are characteristic of the genus Polygonia, which is why species in the genus are commonly referred to as anglewing butterflies. Comma butterflies can be identified by their prominent orange and dark brown/black dorsal wings.
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.
Dryas iulia, commonly called the Julia butterfly, Julia heliconian, the flame, or flambeau, is a species of brush-footed butterfly. The sole representative of its genus Dryas, it is native from Brazil to southern Texas and Florida, and in summer can sometimes be found as far north as eastern Nebraska. Over 15 subspecies have been described.
Leptidea sinapis, or the wood white butterfly of the family Pieridae, is a small white butterfly that is mainly found in England, Ireland, and Northern Europe. The butterfly has white wings with grey or yellow markings near the center or tip of the wing. It flies slowly and low over its shrubbery habitat. Males initiate courtship with females and can mate multiply, while females tend to only mate once in their lifetime.
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.
The ocoee salamander is a species of salamander in the family Plethodontidae. This salamander has a variety of colors and patterns, and got its name from Tennessee state wildflower. Its natural habitats are temperate forests, rivers, intermittent rivers, freshwater springs and wet rocks in mountainous areas of the Southeastern United States. It was first described by Nicholls in 1949. They are territorial and feed on small invertebrates. It is widely distributed in the southeastern United States and is listed as "Least Concern" by the International Union for Conservation of Nature.
The variable checkerspot or Chalcedon checkerspot is a butterfly in the family Nymphalidae. It is found in western North America, where its range stretches from Alaska in the north to Baja California in the south and extends east through the Rocky Mountains into Colorado, Montana, New Mexico and Wyoming. The butterfly is usually brown or black with extensive white and yellow checkering and some red coloration on the dorsal wing. Adult wingspan is 3.2–5.7 cm (1.3–2.2 in). Adult butterflies feed on nectar from flowers while larvae feed on a variety of plants including snowberry (Symphoricarpos), paintbrush (Castilleja), Buddleja, Diplacus aurantiacus and Scrophularia californica.
Cressida cressida, the clearwing swallowtail or big greasy, is a Troidine swallowtail butterfly found in northern Australia, New Guinea, Maluku, and Timor. It is in the monotypic genus Cressida.
Edith's checkerspot is a species of butterfly in the family Nymphalidae. It is a resident species of western North America and among the subspecies, entomologists have long been intrigued by their many phenotypic variations in coloration, wing length, and overall body size. Most populations are monophagous and rely on plants including Plantago erecta and Orthocarpus densiflorus as their host species in developing from eggs through to larvae, pupae, and mature butterflies. Males exhibit polygyny whereas females rarely mate more than once. Males devote most of their attention to mate acquisition, and such mate locating strategies such as hilltopping behavior have developed. Climate change and habitat destruction have impacted certain subspecies. Three subspecies in particular, Euphydryas editha quino, Euphydryas editha bayensis and Euphydryas editha taylori, are currently under protection via the Endangered Species Act.
Pararge xiphioides, the Canary speckled wood, is a butterfly of the family Nymphalidae. It is found in the Canary Islands on La Gomera, La Palma, Tenerife and Gran Canaria.
Bicyclus anynana is a small brown butterfly in the family Nymphalidae, the most globally diverse family of butterflies. It is primarily found in eastern Africa from southern Sudan to Eswatini. It is found mostly in woodland areas and flies close to the ground. Male wingspans are 35–40 mm and female wingspans are 45–49 mm.
In ecology, contest competition refers to a situation where available resources, such as food and mates, are utilized only by one or a few individuals, thus preventing development or reproduction of other individuals. It refers to a hypothetical situation in which several individuals stage a contest for which one eventually emerges victorious. Contest competition is the opposite of scramble competition, a situation in which available resources are shared equally among individuals.
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