Maculinea alcon
Encyclopedia
Phengaris alcon, more commonly known as Alcon Blue or Alcon Large Blue, is a butterfly
of the Lycaenidae
family and is found in Europe
and Northern Asia
.
It can be seen flying in mid to late summer. Like some other species of Lycaenidae, its larva
(caterpillar) stage depends on support by certain ant
s; it is therefore known as a myrmecophile.
The butterfly lays its eggs onto the Marsh Gentian
(Gentiana pneumonanthe); in the region of the Alps
they are sometimes also found on the related Willow Gentian (Gentiana asclepiadea
). The caterpillars eat no other plants.
Alcon larvae leave the food plant when they have grown sufficiently (4th instar
) and wait on the ground below to be discovered by ants. The larvae emit surface chemicals (allomone
s) that closely match those of ant larvae, causing the ants to carry the Alcon larvae into their nests and place them in their brood chambers, where they are fed by worker ants and where they devour ant larvae.
When the Alcon larva is fully developed it pupates. Once the adult hatches it must run the gauntlet of escaping. The ants recognise the butterfly to be an intruder, but when they go to attack it with their jaws they can't grab anything substantial as the newly emerged adult butterfly is thickly clothed in loosely attached scales.
Over time, some ant colonies that are parasitized in this manner will slightly change their larva chemicals as a defense, leading to an evolutionary "arms race" between the two species.
Generally, Lycaenidae species which have a myrmecophilous relationship with the ant genus
Myrmica
are locked to primary host
specificity.
The Alcon Blue is unusual in this regard in that it uses different host species in different locations throughout Europe. It is known to use Myrmica scabrinodis, Myrmica ruginodis
, and Myrmica rubra
as the primary host within differing European zones.
The Phengaris alcon larvae are sought underground by the Ichneumon
eumerus wasp
. On detecting a P. alcon larva the wasp enters the nest and sprays a pheromone that causes the ants to attack each other. In the resulting confusion the wasp locates the butterfly larva and injects it with its eggs. On pupation, the wasp eggs hatch and consume the chrysalis from the inside.
Orachrysops niobe
, another member of the Lycaenidae from South Africa, has a very similar life-cycle.
Butterfly
A butterfly is a mainly day-flying insect of the order Lepidoptera, which includes the butterflies and moths. Like other holometabolous insects, the butterfly's life cycle consists of four parts: egg, larva, pupa and adult. Most species are diurnal. Butterflies have large, often brightly coloured...
of the Lycaenidae
Lycaenidae
The Lycaenidae are the second-largest family of butterflies, with about 6000 species worldwide, whose members are also called gossamer-winged butterflies...
family and is found in Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
and Northern Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
.
It can be seen flying in mid to late summer. Like some other species of Lycaenidae, its larva
Larva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...
(caterpillar) stage depends on support by certain ant
Ant
Ants are social insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from wasp-like ancestors in the mid-Cretaceous period between 110 and 130 million years ago and diversified after the rise of flowering plants. More than...
s; it is therefore known as a myrmecophile.
The butterfly lays its eggs onto the Marsh Gentian
Marsh Gentian
Gentiana pneumonanthe is a species of the genus Gentiana. It was the first wildflower announced as flower of the year in Germany in 1980.The species can be found in Marshes and Moorlands. It is the host-plant of the Alcon Blue ....
(Gentiana pneumonanthe); in the region of the Alps
Alps
The Alps is one of the great mountain range systems of Europe, stretching from Austria and Slovenia in the east through Italy, Switzerland, Liechtenstein and Germany to France in the west....
they are sometimes also found on the related Willow Gentian (Gentiana asclepiadea
Gentiana asclepiadea
Gentiana asclepiadea is a species of the genus Gentiana. It is native to central and eastern Europe from primarily mountain woodland though it does occur in less wooded open pasture in some areas, perhaps persisting after woodland clearance.One of the larger species within the genus, it produces...
). The caterpillars eat no other plants.
Alcon larvae leave the food plant when they have grown sufficiently (4th instar
Instar
An instar is a developmental stage of arthropods, such as insects, between each molt , until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or assume a new form. Differences between instars can often be seen in altered body proportions, colors, patterns, or...
) and wait on the ground below to be discovered by ants. The larvae emit surface chemicals (allomone
Allomone
An allomone is any chemical substance produced and released by an individual of one species that affects the behaviour of a member of another species to the benefit of the originator but not the receiver...
s) that closely match those of ant larvae, causing the ants to carry the Alcon larvae into their nests and place them in their brood chambers, where they are fed by worker ants and where they devour ant larvae.
When the Alcon larva is fully developed it pupates. Once the adult hatches it must run the gauntlet of escaping. The ants recognise the butterfly to be an intruder, but when they go to attack it with their jaws they can't grab anything substantial as the newly emerged adult butterfly is thickly clothed in loosely attached scales.
Over time, some ant colonies that are parasitized in this manner will slightly change their larva chemicals as a defense, leading to an evolutionary "arms race" between the two species.
Generally, Lycaenidae species which have a myrmecophilous relationship with the ant genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Myrmica
Myrmica
Myrmica is a genus of ants within the subfamily Myrmicinae. It is widespread throughout the temperate regions of the Holarctic and high mountains in Southeast Asia. The genus consists of around 200 known species, and additional subspecies, although this figure is likely only to rise as soon as...
are locked to primary host
Host (biology)
In biology, a host is an organism that harbors a parasite, or a mutual or commensal symbiont, typically providing nourishment and shelter. In botany, a host plant is one that supplies food resources and substrate for certain insects or other fauna...
specificity.
The Alcon Blue is unusual in this regard in that it uses different host species in different locations throughout Europe. It is known to use Myrmica scabrinodis, Myrmica ruginodis
Myrmica ruginodis
Myrmica ruginodis is a species of ant that lives in northern parts of Europe and Asia. It is very similar to M. rubra, but has a more northerly and higher-altitude distribution. Overwintering larvae may become either workers or queen ants, with up to 20 queens living in a colony of up to 2,500...
, and Myrmica rubra
Myrmica rubra
Myrmica rubra, also known as the European fire ant or common red ant, is a species of ant of the genus Myrmica, found all over Europe and in some parts of North America and Asia. They are mainly red in colour, with slightly darker pigmentation on the head. The ants live under stones, fallen trees,...
as the primary host within differing European zones.
The Phengaris alcon larvae are sought underground by the Ichneumon
Ichneumon wasp
The Ichneumonoidea are insects classified in the hymenopteran suborder Apocrita. The superfamily is made up of the ichneumon wasps and the braconids...
eumerus wasp
Wasp
The term wasp is typically defined as any insect of the order Hymenoptera and suborder Apocrita that is neither a bee nor an ant. Almost every pest insect species has at least one wasp species that preys upon it or parasitizes it, making wasps critically important in natural control of their...
. On detecting a P. alcon larva the wasp enters the nest and sprays a pheromone that causes the ants to attack each other. In the resulting confusion the wasp locates the butterfly larva and injects it with its eggs. On pupation, the wasp eggs hatch and consume the chrysalis from the inside.
Orachrysops niobe
Orachrysops niobe
Orachrysops niobe, or the Brenton Blue butterfly is a species of butterfly in the Lycaenidae family. It is endemic to South Africa....
, another member of the Lycaenidae from South Africa, has a very similar life-cycle.
See also
- Phengaris alcon arenaria (Extinct Dutch subspecies)
- Orachrysops niobeOrachrysops niobeOrachrysops niobe, or the Brenton Blue butterfly is a species of butterfly in the Lycaenidae family. It is endemic to South Africa....
Brenton Blue butterfly from South Africa