The group includes:
- Painted lady (Vanessa cardui), which is almost global in its distribution
- Australian painted lady (Vanessa kershawi)
- American (painted) lady (Vanessa virginiensis)
- West Coast lady (Vanessa annabella).
The painted lady (V. cardui), or thistle butterfly, is a large butterfly (wing span 5–9 cm (2.0–3.5 in)) identified by the black and white corners of its mainly deep orange, black-spotted wings. It has five white spots in the black forewing tips and while the orange areas may be pale here and there, there are no clean white dots in them. The hindwings carry four small submarginal eyespots on the dorsal and ventral sides. Those on the dorsal side are black, but in the summer morph sometimes small blue pupils are present.
The American painted lady (V. virginiensis) is most easily distinguishable by its two large hindwing eyespots on the ventral side. V. virginiensis also features a white dot within the subapical field of the forewings set in pink on the ventral side, and often as a smaller clean white dot in the orange of the dorsal side too. A less reliable indicator is the row of eyespots on the dorsal submarginal hindwing; V. virginiensis often has two larger outer spots with blue pupils. The black forewing tips have four to five white spots; usually the largest is whitish orange.
The West Coast lady (V. annabella) does not have obvious ventral eyespots. On the dorsal side, V. anabella llar to V. cardui. Its four ventral eyespots are less clearly defined, and it always sports at least three (often four) blue pupil spots on its dorsal hindwing. Caterpillars are found mainly on Ammobium alatum.
The painted lady caterpillar is usually black with yellowish lines on each side, and a black head; it makes a nest by rolling the edges of a leaf together and securing it with silk. A new nest is made after each moult. The nests are easy to spot on the host plant; they are often messy and filled with the caterpillar’s droppings (which are called frass). The early instar larva spends most of the day concealed, feeding in and around the nest. Later instar larva often wander out to feed at dawn and dusk.
Pupae can be a variety of colours including a metallic green, brown, or bluish-white with some iridescent markings attached at a single point, and as with all the Nymphalidae, hangs vertically with the head down. The pupa can often be found on or close to the host plant.
Painted ladies pollinate the plants and flowers in their habitat. Painted ladies have been recorded feeding from more than 100 plant species, so they can have a big effect on many plant species. Painted ladies are also a part of the food web since they are eaten by birds, bats, and other insects. They can also be used by a large variety of parasites. The parasites attack both the caterpillars and the pupae, using the bodies of the painted ladies for their own development. These parasites include tachinid flies (Exorista segregata and Sturmia bella), ichneumonid wasps (Thyrateles camelinus, Cotesia vanessae, Cotesia vestalis and Dolichogenidea sicaria), and chalcid wasps (Pteromalus puparum).
Lifespan and life cycle
During the first stage of the life cycle, the female painted lady butterfly lays eggs on a plant that attracts painted lady caterpillars, such as hollyhock or thistle. Each egg, which is only the size of a pin head, contains a caterpillar in the very early stages of growth. The egg stage takes about three to five days.
The caterpillar hatches during the larval stage, eating its way out of the egg and then eating the shell. Over the next few days, the caterpillar eats through leaves, growing rapidly and getting stronger. It spins a silk thread to keep itself attached to leaves. As the caterpillar grows bigger, its skin tightens until it is shed to reveal new skin underneath. This skin-shedding process happens four times before the caterpillar is fully grown. At full size, the caterpillar is almost 2 inches (5 cm) long. The caterpillar will continue to spin silk threads so that it remains attached to those leaves.
To begin the pupal or chrysalis stage, the caterpillar attaches itself with a silk pad and hangs upside down on a leaf. About 24 hours later, its skin splits, exposing a dull, bronze-coloured case known as the pupa or chrysalis. The pupa hangs for about a week without movement. Within the pupa, the caterpillar is turning into liquid and changing into a butterfly, a process called metamorphosis.
After that one week, butterfly pushes the pupa from inside until it splits open and the butterfly can slowly emerge. Initially, it has soft, crumpled wings. After resting on the leaf for a short time, the painted lady carefully unfolds its wings to let them dry.
The painted lady's life span is about two weeks after it emerges from its chrysalis. During this time, a female painted lady finds a mate, reproduces and lays eggs to restart the life cycle.
This butterfly is widely distributed all over the Northern hemisphere, and can be seen in all types of habitats except dense forests. Painted ladies lay their eggs on many different plants, and their larvae feed on a wider variety of plants (polyphagus) than most other butterfly species. Even though they are often thought of as the thistle butterfly, and a majority of their eggs are laid on thistles, the larvae feed and can be reared on a varied number of plants and plant types, in several different families.
They can be found on every continent in the world except Antarctica and Australia. The territory size of the painted lady is large enough to cover all of North America, south to Panama. They are also in Asia, Africa, and Europe.
Painted ladies live in areas with wide open areas of plants such as fields and meadows. They can also be found in suburban, agricultural, swamp, bog, marsh, tundra, taiga, desert or dune, chaparral, forest, rainforest, scrub forest, and mountain habitats as well. These butterflies can adjust to living in pretty much any habitat.
Painted lady males have territories that they defend from other males. When a female crosses paths with a male, the male will then court the female in hopes that she will mate with him. Males will mate with multiple females during their lives.
Painted ladies will mate year round in warm climates, but do not mate during the winter in cooler places. Females will lay about 500 eggs, each egg singly laid on a plant that the caterpillar will eat when it hatches. Both male and females are able to mate 5 to 7 days after emerging from their pupa. Mating and reproduction also takes place throughout the mass migrations that this species undertakes, producing multiple generations throughout the migration. In laboratories, scientists have seen up to 8 generations in a year.
Every year, painted lady butterflies make huge migrations from Africa to Europe and back again. They also do this in North America, from Mexico to the northern United States and Canada and back. The migrations can be up to 15,000 km (9,320 miles) long. In the spring, they begin moving north as the temperatures become too warm in Africa or Mexico. Along the way, they mate and reproduce. Since most adult butterflies do not live more than a month, it is not just one generation of butterfly that makes this migration. Instead, it is their offspring and their offsprings' offspring that make the journey. Millions of butterflies can make this journey, though some years there are far less. They reach the northern parts of Europe and North America during the summer, when temperatures are just right for the butterflies. They continue to reproduce, and then they start flying back south in late summer and fall, when temperatures become too cold in the north.
Painted lady butterflies communicate with other butterflies through movement, chemicals, vision, and sound. Caterpillars (larvae) have poor vision, but they can see red through ultraviolet. Adults have better eyes that let them identify food and mates.
|Wikimedia Commons has media related to Vanessa cardui.|
- "Vanessa cardui pupae". Kids' Inquiry of Diverse Species.
- "Painted Lady Larvae". Home Ground Habitats.
- "Vannesa cardui Roles Played in Ecosystem". Kids' Inquiry of Diverse Species.
- Lowe, Tristan; Garwood, Russell P.; Simonsen, Thomas; Bradley, Robert S.; Withers, Philip J. (2013). "Metamorphosis revealed: three dimensional imaging inside a living chrysalis". Metamorphosis Revealed: Three Dimensional Imaging Inside a Living Chrysalis. 10 (84). 20130304. doi:10.1098/rsif.2013.0304. PMC 3673169. PMID 23676900.
- "Life Cycle of a Painted Lady Butterfly". Sciencing.
- "Painted Lady Habitat". Home Ground Habitats.
- "Vanessa cardui Habitats". Kids' Inquiry of Diverse Species.
- "Vanessa cardui Reproduction". Kids' Inquiry of Diverse Species.
- "Vanessa cardui Migration". Kids' Inquiry of Diverse Species.
- "Painted Lady Communication". Kids' Inquiry of Diverse Species.
- Painted lady butterfly (Vanessa cardui): Large format reference quality photographs
- American painted lady butterfly (Vanessa virginiensis): Large format reference quality closeup photographs
- Wildlife photos of painted lady butterfly
- "Vanessa cardui". Integrated Taxonomic Information System. Retrieved 6 February 2006.
- "Vanessa virginiensis". Integrated Taxonomic Information System. Retrieved 6 February 2006.