butterflies
Butterflies are winged insects from the lepidopteran superfamily Papilionoidea, characterized by large, often brightly coloured wings that often fold together when at rest, and a conspicuous, fluttering flight. The oldest butterfly fossi ...
in the family
Pieridae
The Pieridae are a large family (biology), family of butterflies with about 76 genera containing about 1,100 species, mostly from Afrotropical realm, tropical Africa and Indomalayan realm, tropical Asia with some varieties in the more northern ...
. It is
monotypic
In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unisp ...
, being represented by the single species ''Ascia monuste'', commonly known as the great southern white, In this species the sexes may differ with the female being either light or dark colored. It is found from the Atlantic and Gulf coasts of the United States, and south to Argentina. It is migratory along the south-eastern coast of the United States, with strays to
Maryland
Maryland ( ) is a U.S. state, state in the Mid-Atlantic (United States), Mid-Atlantic region of the United States. It borders the states of Virginia to its south, West Virginia to its west, Pennsylvania to its north, and Delaware to its east ...
,
Kansas
Kansas ( ) is a landlocked U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders Nebraska to the north; Missouri to the east; Oklahoma to the south; and Colorado to the west. Kansas is named a ...
, and
Colorado
Colorado is a U.S. state, state in the Western United States. It is one of the Mountain states, sharing the Four Corners region with Arizona, New Mexico, and Utah. It is also bordered by Wyoming to the north, Nebraska to the northeast, Kansas ...
.
Larva
A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect development such as insects, some arachnids, amphibians, or cnidarians typically have a larval phase ...
e have distinct body segments within which there appears to be four to six subsegments. They are purplish-green with two longitudinal, greenish-yellow stripes on each side and the dorsal side. When full-grown, they are approximately one and a quarter inches long. The
wingspan
The wingspan (or just span) of a bird or an airplane is the distance from one wingtip to the opposite wingtip. For example, the Boeing 777–200 has a wingspan of , and a wandering albatross (''Diomedea exulans'') caught in 1965 had a wingsp ...
in adults is 63–86 mm. Adults are on wing all year round in southern Texas, peninsular Florida and along the Gulf Coast.
''A. monuste'' is a migrating species that moves in one direction within its life span and does not return. It breeds in Florida but sometimes migrates along the coast up to 160 km to breed in more suitable areas.
Life history
This species seeks out appropriate plant hosts for
oviposition
The ovipositor is a tube-like organ used by some animals, especially insects, for the laying of eggs. In insects, an ovipositor consists of a maximum of three pairs of appendages. The details and morphology of the ovipositor vary, but typica ...
by detection of compounds called
glucosinolates
Glucosinolates are natural components of many pungent plants such as mustard, cabbage, and horseradish. The pungency of those plants is due to mustard oils produced from glucosinolates when the plant material is chewed, cut, or otherwise dama ...
present in the family
Brassicaceae
Brassicaceae () or (the older but equally valid) Cruciferae () is a medium-sized and economically important Family (biology), family of flowering plants commonly known as the mustards, the crucifers, or the cabbage family. Most are herbaceous pla ...
. Adults appear to prefer to lay their eggs on certain areas of the plant. On kale leaves, for example, the preferred regions are the apical, medium and basal parts of the leaves. The average number of eggs laid is about 43 with as many as 245, being laid singly or in clusters.Liu, T.-X. 2005. Biology and life history of ''Ascia monuste monuste'' (Lepidoptera: Pieridae), a potential pest of cruciferous vegetables. Entomological Society of America 98: 726-731. ''A. m. monuste'' has been observed feeding on the
chorion
The chorion is the outermost fetal membrane around the embryo in mammals, birds and reptiles (amniotes). It is also present around the embryo of other animals, like insects and molluscs.
Structure
In humans and other therian mammals, the cho ...
soon after hatching as their first food, as well as larvae feeding on eggs. It has been suggested that this behavior provides them with extra protein. If a female oviposits on a plant already supporting conspecifics,
cannibalism
Cannibalism is the act of consuming another individual of the same species as food. Cannibalism is a common ecological interaction in the animal kingdom and has been recorded in more than 1,500 species. Human cannibalism is also well document ...
is more likely. Since they have a high growth rate and a non-regulated body temperature, herbivorous insects require a higher quantity of protein. It is questionable that ''A. monuste'' is strictly
herbivorous
A herbivore is an animal anatomically and physiologically evolved to feed on plants, especially upon vascular tissues such as foliage, fruits or seeds, as the main component of its diet. These more broadly also encompass animals that eat n ...
as they often consume conspecific eggs. Larvae have been seen consuming whole eggs from the same clutch or others nearby on the same leaf. This behavior appears to be advantageous from an evolutionary stand point as this is an opportunistic behavior and can increase fitness.
In general, the development time for eggs ranges from 4–5 days in field conditions and 3.4 days in laboratory conditions. The developmental time for the larvae and
pupa
A pupa (; : pupae) is the life stage of some insects undergoing transformation between immature and mature stages. Insects that go through a pupal stage are holometabolous: they go through four distinct stages in their life cycle, the stages th ...
e ranges between subspecies from 11.0– 17.4 days for the first five
instar
An instar (, from the Latin '' īnstar'' 'form, likeness') is a developmental stage of arthropods, such as insects, which occurs between each moult (''ecdysis'') until sexual maturity is reached. Arthropods must shed the exoskeleton in order to ...
s for ''A. m. orseis'', and 6.1– 9.56 days for ''A. m. monuste''. Pupation can be from 5.9 to 10 days long, and adults can live from 4.3 – 5 days for males and 8–10 days for females.
The larvae, known in Brazil as cabbage caterpillars Barros-Bellanda, H.C.H. & F.S. Zucoloto. 2002. Effects of intraspecific competition and food deprivation on the immature phase of ''Ascia monuste orseis'' (Lepidoptera, Pieridae). Iheringia, Série Zoologia 92: 93-98. or kale caterpillars,Barros-Bellanda, H.C.H. & F.S. Zucoloto. 2003. Importance of larval migration (dispersal) for the survival of ''Ascia monuste'' (Godart) (Lepidoptera: Pieridae). Neotropical Entomology 32: 011-017. feed on
Brassicaceae
Brassicaceae () or (the older but equally valid) Cruciferae () is a medium-sized and economically important Family (biology), family of flowering plants commonly known as the mustards, the crucifers, or the cabbage family. Most are herbaceous pla ...
(including '' Cakile maritima'', cultivated cabbage and radish and ''
Lepidium
''Lepidium'' is a genus of plants in the mustard/cabbage family, Brassicaceae. The genus is widely distributed in the Americas, Africa, Asia, Europe, and Australia.Capparidaceae, including nasturtium. Chemical characteristics of the plant that affect the development of the larvae include the: nitrogen content, carbohydrates and water content, as well as physical characteristics such as: hardness, size, form, texture, temporal and spatial distribution and abundance. Nitrogen is required for the production of protein during the early
instar
An instar (, from the Latin '' īnstar'' 'form, likeness') is a developmental stage of arthropods, such as insects, which occurs between each moult (''ecdysis'') until sexual maturity is reached. Arthropods must shed the exoskeleton in order to ...
s.
Newly hatched larvae will remain on a single plant, as they are not very mobile. After the 5th instar, they are more mobile and can move to another plant. Larvae dispersion appears to occur in a random fashion, so in order for the larvae to be successful, the plants need to be close together for them to find another plant.
Intraspecific competition
Intraspecific competition is an interaction in population ecology, whereby members of the same species compete for limited resources. This leads to a reduction in fitness for both individuals, but the more fit individual survives and is able to ...
between larvae generally doesn't occur between the 1st and 2nd instars because they do not consume a lot. Competition may become a problem once they hatch into the final three instars. Adults feed on
nectar
Nectar is a viscous, sugar-rich liquid produced by Plant, plants in glands called nectaries, either within the flowers with which it attracts pollination, pollinating animals, or by extrafloral nectaries, which provide a nutrient source to an ...
lantana
''Lantana'' () is a genus of about 150 species of perennial plant, perennial flowering plants in the verbena family, Verbenaceae. They are native to tropics, tropical regions of the Americas and Africa but exist as an introduced species in num ...
, and
verbena
''Verbena'' (), also known as vervain or verveine, is a genus in the family Verbenaceae. It contains about 150 species of annual and perennial herbaceous or semi-woody flowering plants. The majority of the species are native to the Americas ...
. It is a sporadic pest of crucifer vegetables in southern Texas.
Pest species of Brassicaceae
Damage to the plant is caused by the larvae that, upon hatching, feed on the leaves for almost the entirety of their developmental cycle.Baldin, E.L.L., E.C. Schlick-Souza, A.L. Lourenção & R.S. Camargo. 2014. Resistance of collard greens to ''Ascia monuste orseis'' (Lepidoptera: Pieridae). Arthropod-Plant Interactions 9: 67-74. This can be so damaging, that up to 100% of the entire crop can be lost. One method of decreasing this damage is by the use of pesticides. These, however can be detrimental to human health as well as the environment. Another method that is being explored is the use of host plant resistance, which is safer and more sustainable. Resistant crops are becoming increasingly popular as pesticides have quite a few drawbacks. Resistance can be seen as antixenosis, tolerance and
antibiosis
Antibiosis, also referred to as antagonism, a process of biological interaction between two or more organisms that is detrimental to at least one of them; it can also be an antagonistic association between an organism and the metabolic substance ...
.Schlick-Souza, E.C. & A.L. Lourenção, A.L. 2011. Variation in the host preferences and responses of ''Ascia monuste orseis'' Godart (Lepidoptera: Pieridae) to cultivars of collard greens ''Brassica oleracea'' (L.) var. acephala. Journal of Pest Science 84: 429-436.
Subspecies
*''Ascia monuste monuste'' (southern United States to Suriname)
*''Ascia monuste phileta'' (southeastern United States, northern Bahamas)
*''Ascia monuste virginia'' (Lesser Antilles between Virgin Islands and St. Vincent)
*''Ascia monuste eubotea'' (Greater Antilles, Virgin Islands)
*'' Ascia monuste orseis'' (Brazil)
*''Ascia monuste suasa'' (Peru)
*''Ascia monuste automate'' (Argentina)
*''Ascia monuste raza'' (Baja California Sur)