Vanessa cardui

Vanessa cardui

The painted lady (Vanessa cardui Linnaeus, 1758) is a moth belonging to the Nymphalidae family.

Systematic –
From a systematic point of view it belongs to:
Eukaryota domain,
Kingdom Animalia,
Subkingdom Eumetazoa,
Superphylum Protostomia,
Phylum Arthropoda,
Subphylum Tracheata,
Superclass Hexapoda,
Class Insecta,
Subclass Pterygota,
Endopterygota cohort,
Superorder Oligoneoptera,
Panorpoidea section,
Order Lepidoptera,
Suborder Glossata,
Infraorder Heteroneura,
Ditrysia Division,
Superfamily Papilionoidea,
Family Nymphalidae,
Subfamily Nymphalinae,
Nymphalini Tribe,
Gender Vanessa,
Species V. cardui.
The term is basionym:
– Papilio cardui Linnaeus, 1758.
The terms are synonymous:
– Cynthia cardui (Linnaeus, 1758);
– Cynthia elymi Rambur, 1829;
– Cynthia litoralis de Souza, 1926;
– Papilio belladonna Linnaeus, 1758;
– Papilio carduelis Cramer, 1775;
– Papilio carduelis Seba, 1765;
– Parameis cardui (Linnaeus, 1758);
– Pryrameis martha-maria Stephan, 1924;
– Pyrameis brunnea-albimaculata Reuss, 1915;
– Pyrameis carduelina Alphéraky, 1908;
– Pyrameis carduelis Cramer, 1775;
– Pyrameis carduelis Schultz, 1906;
– Pyrameis cardui (Linnaeus, 1758);
– Pyrameis cardui subsp. brunnea-albimaculata Reuss, 1916;
– Pyrameis cardui subsp. conjuncta Verity, 1919;
– Pyrameis cardui subsp. emielymi Verity, 1919;
– Pyrameis cardui subsp. huntera Lowe, 1902;
– Pyrameis cardui subsp. infaochracea Verity, 1919;
– Pyrameis cardui subsp. infrabrunnea Verity, 1919;
– Pyrameis cardui subsp. infraflava Verity, 1919;
– Pyrameis cardui subsp. infragrisea Verity, 1919;
– Pyrameis cardui subsp. infranigrans Verity, 1919;
– Pyrameis cardui subsp. inops Verity, 1919;
– Pyrameis cardui subsp. japonica Stichel, 1908;
– Pyrameis cardui subsp. litoralis de;
– Pyrameis cardui subsp. minor Cockerell, 1890;
– Pyrameis cardui subsp. ochracea Reuss, 1918;
– Pyrameis cardui subsp. rosacea Reuss, 1916;
– Pyrameis cardui subsp. septiespupillata Verity, 1919;
– Pyrameis cardui subsp. sexispupillata Verity, 1919;
– Pyrameis cardui subsp. universa Verity, 1919;
– Pyrameis elymnias Rambur, 1829;
– Pyrameis flava Bandermann, 1928;
– Pyrameis japonica Stichel, 1908;
– Pyrameis johni Fischer de Waldheim, 1932;
– Pyrameis leachiana Doubleday, 1849;
– Pyrameis minor Cannaviello, 1900;
– Pyrameis pallens Noel, 1881;
– Pyrameis pallida Schøyen, 1881;
– Pyrameis rogeri Meilhan, 1929;
– Pyrameis rosacea Reuss, 1915;
– Pyrameis rosea Pionneau, 1926;
– Pyrameis schoenfellneri Hoffmann, 1925;
– Pyrameis subfracta Stach, 1925;
– Pyrameis takesakiana Katô, 1925;
– Pyrameis varini Meilhan, 1929;
– Vanessa albicans Verity, 1950;
– Vanessa albipuncta Lempke, 1956;
– Vanessa ate Strecker;
– Vanessa belladonna Godart, 1821;
– Vanessa carduelis Seba, 1765;
– Vanessa cardui subsp. albipuncta Lempke, 1956;
– Vanessa cardui subsp. nigripuncta Lempke, 1956;
– Vanessa cardui subsp. pallida Schøyen, 1881;
– Vanessa cardui subsp. stictus Wu & Ma, 2016;
– Vanessa carnea Fritsch;
– Vanessa elymi Rambur, 1829;
– Vanessa inops Verity & Querci, 1924;
– Vanessa inornata Bramson, 1886;
– Vanessa jacksoni A.H.Clark, 1932;
– Vanessa koreana Bryk, 1946;
– Vanessa minor Cockerell, 1890;
– Vanessa minor Gunder, 1928;
– Vanessa nigripuncta Lempke, 1956;
– Vanessa pulchra Chou, Yuan, Yin, Zhang & Chen, 2002;
– Vanessa takesakiana Kato, 1925;
– Vanessa universa Verity, 1919;
– Vanessa wiskotti Standfuss, 1896.
All’interno di questa specie vengono riconosciute le seguenti sottospecie:
– Vanessa cardui subsp. priameis (Schultz, 1906);
– Vanessa cardui subsp. ushuwaia Bryk, 1945.

Geographic Distribution and Habitat –
Vanessa cardui is one of the most widespread butterflies, present on all continents except Antarctica and South America.
It is present in every temperate zone, including the mountains of the tropics. The species is resident only in the warmest areas, but migrates in spring, and sometimes also in autumn. It migrates from North Africa and the Mediterranean to Britain and Europe in May and June, occasionally reaching Iceland, and from the Red Sea basin, via Israel and Cyprus, to Turkey in March and April. The occasional autumn migration is probably due to the control of resource changes; this migration consists of a round trip from Europe to Africa.
The caterpillars of this butterfly feed on a variety of plants of the Asteraceae family, in particular Carduus Crispus. They also feed on boraginaceae, malvaceae (especially Alcea and Malva descenda). Adults sip nectar from a wide variety of wildflowers and cultivated flowers. The most common are thistle (hence the name), Buddleja, Aster, Bidens and Zinnia

Morphology –
The Vanessa cardui is a Lepidoptera and can be recognized as the adults are butterflies with a wingspan of approximately 60 mm, with brightly colored wings (orange with brownish and white spots).
Both the male and the female have a reddish-ochreous background color, olive-ochre-brown basal areas; cilia black, alternating with white, anterior part with a black broken band of irregular shape oblique outwards crossing from the center of the cell to the disk above the submedian vein; the apical area from the end of the cell and the outer edge are also black; before the apex there is a short white stripe oblique outwards and a curved row of four round spots, the second and third being small; a pale marginal lunar line with the upper portion more defined and whitish.
The hind wing has a blackish spot from the costal vein across the end of the cell, a partially confluent curved disc band, a submarginal row of lunulae and then a marginal row of somewhat scutiform spots; between the disc band and the submarginal lunulae there is a row of five round black spots, which in some specimens show a light and dark external ring.
The lower anterior part is a brighter bone-ochraceous colour, the apical area and the external margin are much lighter, the apex is olive-brown-ochraceous; irregular disc band as above, subapical white stripe, row of distinct marginal spots and lunulae; base of the wing and gap before the end of the white cell.
The hind wing is transversely marbled with olive brown ocher and dotted with black scales; crossed by a sinuous basal and disc band of a whitish or pale color and intersected by white veins; a disc-outer row of five ocelli, the upper one smaller and usually imperfect, the second and fifth larger, the fourth with a black center dotted with blue and surrounded by yellow, and the second and fifth also with a outer black ring; grey-purple submarginal lunulae, delimited by a whitish band; outer margin ocher.
The body is olive-brown-ochre in colour, belly with ochreous bands; palps blackish above, white below; greyish-white lower body and legs; antennae black above, tip and reddish below.
The larvae are a few centimeters long, variable in color and equipped with yellowish spiny processes arranged along the body.

Aptitude and biological cycle –
Vanessa cardui is a phytophagous insect that overwinters as a chrysalis (in warmer regions even as an adult), and on average completes two generations per year (less frequently 1 or 3 generations). Generally the first adults (of the 1st generation) emerge from April-May, while the second generation ones appear in the summer (July).
This butterfly displays a unique system of continuous mating, in all seasons, including winter. This can be attributed to its migratory patterns, which significantly influence its mating behavior. During European migrations, butterflies immediately begin mating and laying eggs upon arrival in the Mediterranean in spring, starting in late May.
In the United States, butterflies migrating north experience unfavorable mating conditions, and many butterflies have limited reproductive capabilities.
During the migratory process, these butterflies begin to breed and reproduce entirely during their migration. Scientists have failed to find evidence of their overwintering; this may be because they migrate to warmer places to survive and reproduce. Females may temporarily suspend their flight when they are “ready to oviposit; this gives them the opportunity to continuously breed during their migrations. Because these butterflies are constantly migrating, males are thought to lack a consistent territory.
More specifically, they locate certain perches, hilltops, forest meadow edges, or other landmarks where they will remain until, presumably, a female arrives to mate.
Equally important for reproduction is males’ display of polygynous mating behavior, in which they often mate with more than one female. This is important because the benefits can replace the costs of polygyny as no permanent breeding ground is used. After mating, which generally takes place in the afternoon, the females lay their eggs one by one in the desired breeding places.
Females have been observed to have relatively “high” biotic potential, meaning that each produces a large number of offspring. This perpetual influx of reproduction may be the reason these butterflies have propagated so successfully. An interesting aspect observed by scientists is that these butterflies like to fly towards the rain. Further studies have suggested that large amounts of rainfall might somehow “activate more eggs or induce better larval development”. Inhabited locations begin to observe a large influx of new generations of these butterflies in autumn, particularly in September and October. Their reproductive success declines relatively during the winter, mainly until November. However, they continue to reproduce, a rather unique aspect of butterfly behavior. Scientists hypothesize that these extensive migratory patterns help this species find suitable conditions for breeding, thus offering a possible reason why these butterflies continually mate.
As regards the biological cycle, the egg hatches 3 to 5 days after being laid. The caterpillar takes 15 to 21 days to develop into a chrysalis. A similar amount of time is needed to go from the chrysalis stage to the final butterfly stage. Once the metamorphosis has taken place, it does not remain in the same area for long: in its life it flies for over 1,000 kilometres.

Ecological Role –
Vanessa cardui has the ability to migrate and usually spends winters only in the tropical belt and sometimes in the warmer southern areas of the Mediterranean (for example in Sicily), but in spring, and sometimes again in autumn, it migrates. For example, we see it move from North Africa and the Mediterranean to southern and central Europe up to Great Britain in the months of May and June.
Based on experimental data, the migratory pattern of this butterfly in northern Europe apparently does not follow a strict northwest direction. The findings suggest that these butterflies may adapt their migration patterns in response to local topographical features and weather conditions, such as strong winds. The laboratory-reared butterflies of the autumn generation were able to distinguish a southern orientation for a return migration path. According to the same laboratory study, when the butterflies were isolated from the sun, they were unable to orient themselves in a specific direction, unlike those who had access to the sun. This suggests that V. cardui requires a direct view of the sky, involving the use of a solar compass to orient its migratory direction and maintain a straight flight path.
These butterflies have a visual system that resembles that of a honey bee. The adult eyes of V. cardui contain ultraviolet, blue, and green opsins. Unlike other butterflies, such as the monarch butterfly, these do not have red receptors, which means they are not sensitive to red light. Behavioral studies on the similar species, Vanessa atalanta, have shown that V. atalanta cannot distinguish yellow light from orange light or orange light from red light.
The adult specimens of this butterfly feed on flower nectar and aphid honeydew. The females oviposit on plants with nectar immediately available for the adults even if this involves high mortality of the larvae. This lack of discrimination means they don’t take volatile chemicals released by potential host plants into account when looking for egg-laying choices.
The availability of resources for adults dictates preference for areas with specific flowers. Flowers with more nectar available result in a greater number of eggs being deposited on the plants. This reinforces the idea that this butterfly does not discriminate between host plants and chooses primarily based on the availability of adult food sources, even if this increases the mortality rate of the offspring.
Groups of two to eight of these butterflies have been observed to fly in circles around each other for approximately one to five seconds before separating, symbolizing courtship. Groups of butterflies usually fly no further than 15 feet (4.5 m) from their starting point. To establish and defend their territories, adult males roost in the late afternoon in areas where females are most likely to appear. Once the male spots a female of the same species, he begins chasing her.
V. cardui establishes territories within areas sheltered by hedges. It tends to live in sunny, well-lit, open environments and is often attracted to open areas full of flowers and clovers. Adults spend time in small depressions in the ground on cloudy days.
The larvae feed mainly on Asteraceae species, including Cirsium, Carduus, Centaurea, Arctium, Onopordum, Helianthus and Artemisia. In general they use over 300 host plants registered according to the HOSTS database.
As for their defense systems from other organisms, the main defense mechanisms include flight and mimicry. Caterpillars hide in small silken nests on top of leaves from their main predators which include wasps, spiders, ants and birds.
V. cardui is a fairly polyphagous defoliator species that also presents migratory phenomena (also from North Africa); in Italy it mainly damages the artichoke where the larvae develop on the leaves which they devour after having gathered them in a characteristic way with silky threads.
To date, this moth has only been fought in cases of heavy infestations with plant protection products registered for the various crops considered. For the horticultural crops on which it is registered, Bacillus thuringiensis ssp, kurstaki, an organic product with good efficacy and low environmental impact, can be used.

Guido Bissanti

Sources
– Wikipedia, the free encyclopedia.
– GBIF, the Global Biodiversity Information Facility.
– Russo G., 1976. Agricultural Entomology. Special Part. Liguori Editore, Naples.
– Pollini A., 2002. Manual of applied entomology. Edagricole, Bologna.
– Tremblay E., 1997. Applied entomology. Liguori Editore, Naples.

Photo source:
– https://inaturalist-open-data.s3.amazonaws.com/photos/252700096/original.jpeg
– https://inaturalist-open-data.s3.amazonaws.com/photos/251824211/original.jpeg