Garden tiger moth | |
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Resting pose | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Class: | Insecta |
Order: | Lepidoptera |
Superfamily: | Noctuoidea |
Family: | Erebidae |
Subfamily: | Arctiinae |
Genus: | Arctia |
Species: | A. caja |
Binomial name | |
Arctia caja | |
Synonyms [1] | |
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The garden tiger moth or great tiger moth [2] (Arctia caja) is a moth of the family Erebidae. Arctia caja is a northern species found in the US, Canada, and Europe. [3] [4] The moth prefers cold climates with temperate seasonality, as the larvae overwinter, [3] and preferentially chooses host plants that produce pyrrolizidine alkaloids. [5] [6] [3] However, garden tiger moths are generalists, and will pick many different plants to use as larval host plants. [5] [4] [3]
The conspicuous patterns on its wings serve as a warning to predators because the moth's body fluids are poisonous. Their effects are not yet fully known, but these toxins contain quantities of neurotoxic choline esters which act by interfering with the acetylcholine receptor. The colours are also ideal for frightening predators such as small birds—the moth normally hides its hindwings under the cryptic forewings when resting. Between stored toxins, conspicuous warning coloration, and sound cues that are generated mostly as a response to bats, A. caja clearly presents itself as an inedible target for predators. [6] [7]
The garden tiger moth has a wingspan of 45 to 65 millimeters (1.8 to 2.6 in). The design of the wings vary; the front wings are brown with a white pattern (which is sometimes missing), the back wings are orange with a pattern of black dots. There are many aberrations (pattern and colour variants), partly obtained artificially and partly by chance. Oberthür, a French entomologist, mentions about 500 different variants shown in 36 figures. Seitz gives an account of some named aberrations. [3]
The garden tiger moth lives in the northern United States, Canada, and Europe. It prefers cold, temperate climates. [4] [3] The garden tiger moth is found throughout much of the Palearctic, in Europe as far north as Lapland, in Northern Asia and Central Asia, and in North America. In the mountains (Tien Shan), this species is found up to an elevation of 3,000 metres (9,800 ft).
This species prefers numerous types of wild habitat, from grasslands to forests. Because of its generalist diet, it is not constrained by features such as host plant location. The only constant quality of a habitat for these animals is that it must be seasonal and cool, and like many members of Genus Arctia, tropical climates do not suit garden tiger moth larvae or adults. [5] [3] [4] [6]
The larvae of A. caja are generalists, meaning they eat a large variety of plants without much specialization. However, most larvae of this species obtain their characteristic toxic compounds from their diet, which can vary from foxglove (and members of the daisy family) [5] to species in completely other plant families, such as plantago. [8]
Because of A. caja’s generalist diet while in the larval stage, it is subject to a wide variety of plant defenses. One study tested plant health with and without beneficial fungus known as Arbuscular mycorrhiza (AM), and saw that Plantago lanceolata with beneficial fungus produce more anti-herbivore toxins, which negatively influenced caterpillar growth. The beneficial fungus gained sugars from the plant, while the plant gained soil nutrients from the fungus, such as phosphorus and nitrogen. Due to the plant-fungus symbiosis, plants were able to produce more toxins than normal due to the fungus’ acquisition of additional usable resources from the soil, and in turn harm the larvae's consumption of leaf matter. The effectiveness of this plant response was tested on several species of Lepidoptera. [8]
Adults primarily consume solely floral nectar, and do not have a noticeable specialty.[ citation needed ]
A. caja hatches at the end of summer (from August to September), overwinters once, reemerges in spring, and finishes growth by June. From July to August (or September in warmer climates) the adults are active, primarily at night. Eggs are laid on leaf surfaces and the larvae hatch and feed shortly after the previous generation has died. After feeding for a few months, the larvae go into dormancy while covered in ground matter. In spring, the larvae resume feeding and pupate. By June or July, adults emerge, all from the same generation that was laid in the previous fall. It is key to note that during all life stages there is no generation overlap, either as adults or larvae. [9] [3] [4]
The caterpillars of this species are, like many caterpillars of the tiger moth family, “fuzzy” in appearance, leading them to be called "woolly bears" by casual observers.[ citation needed ] Once the caterpillars reach a certain size, they acquire hollow tubes that often contain irritating compounds. [10] The larvae depend upon the host plant for their toxic compounds, [11] [5] which they convert from plant defense compounds to larval and adult protection compounds. [6] The caterpillars can grow to a maximum size of 6 cm (2.4 in) long.
Adults are active from June to September (or August in more northern climates) [3] [4] predominantly at night. [9] They have red hairs on their cervical regions with glands nearby and patterning across the wings that is meant to warn and advertise toxicity (neurotoxic choline esters). [12]
While not often eaten due to its toxicity, naïve birds will on rare occasion consume either the adult or larval stages of this species. [10] [5] [11]
The larval form of A. caja is parasitized by quite a few endoparasites, which usually grow as larvae inside the living host (in this case a caterpillar). Examples include:
All of the listed species of parasites are flies, and they all parasitize during their larval stages. [6]
Adult garden tiger moths exhibit clear warning signals, which they share with other tiger moths to advertise very real toxicity upon consumption. [13] [11] [5] Adults can also spray an irritating compound when threatened.[ citation needed ] The chemical, produced in glands that are exposed when threatened, is a choline ester.[ citation needed ] A similar compound is found in the tissues of the adults, with the eggs, gonads, and abdomens having the highest concentrations. [5]
Arctia caja is very well adapted to cold temperate climates, and is closely related to many other tiger moths both molecularly and genetically. Although it has variable patterning, it is still quite genetically and molecularly similar to other species that have been separated from A. caja due to appearance, such as A. intercalaris, A. martinhoneyi, A. thibetica, A. brachyptera, and A. opulenta. Evidence for combining some of these species does not seem strong enough to create conclusions in that regard. [13]
Adults can make rasping sounds with their wings and can emit high pitched squeaking sounds that are audible to humans. [14] These sounds have been found to affect bat behavior, as the squeaks of this insect cause bats to avoid the noxious moth. Bats that could associate squeaking or clicking sounds as indicative of toxic prey quickly used sound alone as a deterrent. [7]
The digestion of this species is most remarkable in the larval stage. The host plants of this species almost always carry toxins known as pyrrolizidine alkaloids. [6] [5] [11] To deal with this the caterpillars have developed the capacity to metabolize a wide range of toxins using unique enzymes. These enzymes both convert the plant's toxins into a non-toxic form, but they also allow the larval A. caja to later use these toxins in an altered form for protection. [6]
The larvae of this species overwinter in ground vegetation, and in spring they finish larval development and pupate. [4]
The hairs on the caterpillars are known to cause hives and irritation in humans, as well as other mammals. [10] The adults’ spray can also cause irritation, and rare cases of “stinging” sensations have been recorded.[ citation needed ]
The garden tiger moth is now protected in the UK under the Biodiversity Action Plan (BAP). [15] Its numbers in the UK have declined by 89% over the past 30 years. [16] The BAP in 2007 added the garden tiger moth to its list of species in need of habitat protection in light of these recent declines in suitable habitat. The plan aims to provide greater habitat protection and conservation, with the hopes of stabilizing the A. caja populations that remain in the UK.
The garden tiger moth population decline is of concern for both laboratory research and in nature. [17] [13] [4] A possible way to combat this in a laboratory setting is to use synthetic food. While not ideal, it resolves many issues that arise when trying to raise captive Lepidoptera. Concerns such as food sterility are quickly resolved, along with issues of gathering hard to find or cultivate host plant material. Many larvae, including those of A. caja, can consume synthetic food, which is based primarily on agar, powdered cellulose, cabbage, sucrose, salts, and wheat germ. Synthetic options appear to be a promising way to raise lab populations of this species, for conservation or for study. [17]
Caterpillars are the larval stage of members of the order Lepidoptera.
Lepidoptera or lepidopterans is an order of winged insects that includes butterflies and moths. About 180,000 species of the Lepidoptera have been described, representing 10% of the total described species of living organisms, making it the second largest insect order with 126 families and 46 superfamilies. and one of the most widespread and widely recognizable insect orders in the world.
The Noctuidae, commonly known as owlet moths, cutworms or armyworms, are a family of moths. They are considered the most controversial family in the superfamily Noctuoidea because many of the clades are constantly changing, along with the other families of the Noctuoidea. It was considered the largest family in Lepidoptera for a long time, but after regrouping Lymantriinae, Catocalinae and Calpinae within the family Erebidae, the latter holds this title now. Currently, Noctuidae is the second largest family in Noctuoidea, with about 1,089 genera and 11,772 species. This classification is still contingent, as more changes continue to appear between Noctuidae and Erebidae.
The Arctiinae are a large and diverse subfamily of moths with around 11,000 species found all over the world, including 6,000 neotropical species. This subfamily includes the groups commonly known as tiger moths, which usually have bright colours, footmen, which are usually much drabber, lichen moths, and wasp moths. Many species have "hairy" caterpillars that are popularly known as woolly bears or woolly worms. The scientific name Arctiinae refers to this hairiness. Some species within the Arctiinae have the word "tussock"' in their common names because they have been misidentified as members of the Lymantriinae subfamily based on the characteristics of the larvae.
Pyrrharctia isabella, the Isabella tiger moth, whose larval form is called the banded woolly bear, woolly bear, or woolly worm, occurs in the United States and southern Canada. It was first formally named by James Edward Smith in 1797.
Greta oto is a species of brush-footed butterfly and member of the subfamily Danainae, tribe Ithomiini, and subtribe Godyridina. It is known by the common name glasswing butterfly for its transparent wings, which allow it to camouflage without extensive coloration. In Spanish-speaking regions, it may also be referred to as espejitos, meaning "little mirrors" because of its transparent wings. The butterfly is mainly found in Central and northern regions of South America, with sightings as far north as Texas and as far south as Chile. While its wings appear delicate, the butterfly is able to carry up to 40 times its own weight. In addition to its wing physiology, the butterfly is known for behaviors such as long migrations and lekking. Greta oto closely resembles Greta andromica.
Danaus chrysippus, also known as the plain tiger, African queen, or African monarch, is a medium-sized butterfly widespread in Asia, Australia and Africa. It belongs to the Danainae subfamily of the brush-footed butterfly family Nymphalidae. Danainae primarily consume plants in the genus Asclepias, more commonly called milkweed. Milkweed contains toxic compounds, cardenolides, which are often consumed and stored by many butterflies. Because of their emetic properties, the plain tiger is unpalatable to most predators. As a result, its colouration is widely mimicked by other species of butterflies. The plain tiger inhabits a wide variety of habitats, although it is less likely to thrive in jungle-like conditions and is most often found in drier, wide-open areas.
Halysidota tessellaris, also called the pale tiger moth, banded tussock moth, and tessellated halisidota, is in the family Erebidae and the tribe Arctiini, the tiger moths. The species was first described by James Edward Smith in 1797. Like many related species, adult moths have chemical defenses acquired from its host plants, in this case, alkaloids. Larval behaviors suggest that they are chemically protected; they have not been analyzed for alkaloid content.
The giant swallowtail is the largest butterfly in North America. It is abundant through many parts of eastern North America; populations from western North America and down into Panama are now considered to belong to a different species, Papilio rumiko. Though it is often valued in gardens for its striking appearance, its larval stage can be a serious pest to citrus farms, which has earned its caterpillars the names orange dog or orange puppy. The giant swallowtail caterpillars possess remarkable camouflage from predators by closely resembling bird droppings. They use this, along with their osmeteria, to defend against predators such as wasps, flies, and vertebrates.
Pyrrolizidine alkaloids (PAs), sometimes referred to as necine bases, are a group of naturally occurring alkaloids based on the structure of pyrrolizidine. Pyrrolizidine alkaloids are produced by plants as a defense mechanism against insect herbivores. More than 660 PAs and PA N-oxides have been identified in over 6,000 plants, and about half of them exhibit hepatotoxicity. They are found frequently in plants in the Boraginaceae, Asteraceae, Orchidaceae and Fabaceae families; less frequently in the Convolvulaceae and Poaceae, and in at least one species in the Lamiaceae. It has been estimated that 3% of the world’s flowering plants contain pyrrolizidine alkaloids. Honey can contain pyrrolizidine alkaloids, as can grains, milk, offal and eggs. To date (2011), there is no international regulation of PAs in food, unlike those for herbs and medicines.
Utetheisa pulchella, the crimson-speckled flunkey, crimson-speckled footman, or crimson-speckled moth, is a moth of the family Erebidae. The species was first described by Carl Linnaeus in his 1758 10th edition of Systema Naturae.
Arctia plantaginis, the wood tiger, is a moth of the family Erebidae. Several subspecies are found in the Holarctic ecozone south to Anatolia, Transcaucasus, northern Iran, Kazakhstan, Mongolia, China, Korea and Japan. One subspecies is endemic to North America.
The hemlock moth, also known as the defoliating hemlock moth or poison hemlock moth, is a nocturnal moth species of the family Depressariidae. Of Palaearctic origin, it was first found in North America in 1973 when it was accidentally introduced. The moth is now widespread throughout the northern half of the United States, southern Canada, northern Europe, and, more recently, New Zealand and Australia. The larval form grows to around 10 mm, while the adults wingspan is between 17 mm and 19 mm.
Utetheisa ornatrix, also called the ornate bella moth, ornate moth, bella moth or rattlebox moth is a moth of the subfamily Arctiinae. It is aposematically colored ranging from pink, red, orange and yellow to white coloration with black markings arranged in varying patterns on its wings. It has a wingspan of 33–46 mm. Moths reside in temperate midwestern and eastern North America as well as throughout Mexico and other parts of Central America. Unlike most moths, the bella moth is diurnal. Formerly, the bella moth or beautiful utetheisa of temperate eastern North America was separated as Utetheisa bella. Now it is united with the bella moth in Utetheisa ornatrix.
Autohaemorrhaging, or reflex bleeding, is the action of animals deliberately ejecting blood from their bodies. Autohaemorrhaging has been observed as occurring in two variations. In the first form, blood is squirted toward a predator. The blood of these animals usually contains toxic compounds, making the behaviour an effective chemical defence mechanism. In the second form, blood is not squirted, but is slowly emitted from the animal's body. This form appears to serve a deterrent effect, and is used by animals whose blood does not seem to be toxic. Most animals that autohaemorrhage are insects, but some reptiles also display this behaviour.
Pyrrolizidine alkaloid sequestration by insects is a strategy to facilitate defense and mating. Various species of insects have been known to use molecular compounds from plants for their own defense and even as their pheromones or precursors to their pheromones. A few Lepidoptera have been found to sequester chemicals from plants which they retain throughout their life and some members of Erebidae are examples of this phenomenon. Starting in the mid-twentieth century researchers investigated various members of Arctiidae, and how these insects sequester pyrrolizidine alkaloids (PAs) during their life stages, and use these chemicals as adults for pheromones or pheromone precursors. PAs are also used by members of the Arctiidae for defense against predators throughout the life of the insect.
Creatonotos gangis, the Baphomet moth or Australian horror moth, is a species of arctiine moth in South East Asia and Australia. It was described by Carl Linnaeus in his 1763 Centuria Insectorum.
Arctia testudinaria, or Patton's tiger, is a moth of the family Erebidae. It was described by Geoffroy in 1785. It is found from northern Spain to southern and central France and southern Switzerland to north-eastern and southern Italy. It has also been recorded from Great Britain. The habitat consists of grasslands, slopes, forest edges, clear dry forests, cliffs and mountain slopes, maquis, garrigues and dry meadows.
Hydroxydanaidal is an insect pheromone synthesized by some species of moth from pyrrolizidine alkaloids found in their diet.
Kleptopharmacophagy is a term used for describing the ecological relationship between two different organisms, where the first is stealing the second's chemical compounds and consuming them. This scientific term was proposed by Australian, Singaporean, and American biologists in September 2021 in an article that was published in the journal Ecology by the Ecological Society of America. The phenomenon was first noticed in milkweed butterflies that were attacking caterpillars and drinking their internal liquid, proposedly to obtain toxic alkaloids used for defense, as well as for mating purposes.
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