''Dinocampus coccinellae'' is a
braconid wasp
The Braconidae are a family of parasitoid wasps. After the closely related Ichneumonidae, braconids make up the second-largest family in the order Hymenoptera, with about 17,000 recognized species and many thousands more undescribed. One analysis ...
parasite
Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has ...
of
coccinellid beetles, including the spotted lady beetle, ''
Coleomegilla maculata
''Coleomegilla maculata'', commonly known as the spotted lady beetle, pink spotted lady beetle or twelve-spotted lady beetle, is a large coccinellid beetle native to North America. The adults and larvae feed primarily on aphids and the species ...
''. ''D. coccinellae'' has been described as turning its
ladybird
Coccinellidae () is a widespread family of small beetles ranging in size from . They are commonly known as ladybugs in North America and ladybirds in Great Britain. Some entomologists prefer the names ladybird beetles or lady beetles as they ...
host into a temporary "zombie" guarding the wasp
cocoon. About 25% of ''
Coleomegilla maculata
''Coleomegilla maculata'', commonly known as the spotted lady beetle, pink spotted lady beetle or twelve-spotted lady beetle, is a large coccinellid beetle native to North America. The adults and larvae feed primarily on aphids and the species ...
'' recover after the cocoon they are guarding matures, although the proportion of other ladybird species which recover is much lower.
Description
In 1802, Schrank first described a female adult of this species as "Lady-bird killer 2155. Deep black, eyes green; head, front legs, and apex of the petiolate abdomen mussel-brown."
[ (A ]petiolate
Petiole may refer to:
*Petiole (botany), the stalk of a leaf, attaching the blade to the stem
*Petiole (insect anatomy)
In entomology, petiole is the technical term for the narrow waist of some hymenopteran insects, especially ants, bees, a ...
abdomen is one whose basal segment is stalk-like, that is, long and slender.) Nearly all ''D. coccinellae'' are female offspring of unfertilized eggs, although males are also occasionally found. The male, when observed, has no ovipositor
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 typical ...
and is slimmer and darker than females.
Biology
The mature female wasp seeks out adult female ladybirds, although they will sometimes oviposit into a male adult or larva
A larva (; plural larvae ) 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.
The ...
l instar
An instar (, from the Latin '' īnstar'', "form", "likeness") is a developmental stage of arthropods, such as insects, between each moult (''ecdysis''), until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or ass ...
. One egg is planted in the host's soft underbelly. The wasp larva hatches after 5–7 days into a first instar larva with large mandibles
In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower tooth, teeth in place. The mandible sits beneath the maxilla. It is the only movabl ...
and proceeds to remove any other eggs or larvae before beginning to feed on the ladybird's fat bodies and gonads.[
The wasp larva inside the ladybird goes through four larval instars in 18–27 days.][ Meanwhile, the ladybird continues to forage and feed until the wasp larva, when it is ready to emerge, paralyzes the ladybird before tunneling out.] It pupates in a cocoon attached to the leg of the living ladybird, whose brightly colored body and occasional twitching reduce predation. A growing ''D. coccinellae'' wasp nestled in its cocoon is extremely vulnerable, and other insects will devour it. If one of these predators tries to eat it, the ladybird retaliates, scaring it off. The ladybird becomes the parasite's bodyguard, by protecting it from predators. However, wasp cocoons protected in this way develop into adults that produce fewer eggs, due to the energy demands of maintaining a living protector.
Ladybirds paralyzed, twitching, and attached to the cocoon of ''D. coccinellae'' have been compared to zombie
A zombie (Haitian French: , ht, zonbi) is a mythological undead corporeal revenant created through the reanimation of a corpse. Zombies are most commonly found in horror and fantasy genre works. The term comes from Haitian folklore, in whic ...
s by many writers. After 6–9 days, the wasp emerges from the cocoon.[ Remarkably, some 25% of ladybirds revive and emerge from paralysis once the cocoon has been emptied.][ The paralytic effect has been proposed to be associated with an RNA virus, '']Dinocampus coccinellae paralysis virus
''Dinocampus coccinellae paralysis virus'' (DcPV) is a single-stranded, positive-sense RNA virus of insects, in the picorna-like virus family ''Iflaviridae'', which was first characterised in 2015. It asymptomatically infects the parasitic brac ...
''.
Ecology
''Dinocampus coccinellae'' can itself be parasitised by ''Gelis agilis
''Gelis agilis'' is a tiny wingless hyperparasitoid wasp that attacks the parasitoid wasp ''Cotesia glomerata'' and other parasitoids, like ''Dinocampus coccinellae''.
References
{{Taxonbar, from=Q2751372
Ichneumonidae
Hyperparasites ...
'', a hyperparasite
A hyperparasite, also known as a metaparasite, is a parasite whose host, often an insect, is also a parasite, often specifically a parasitoid. Hyperparasites are found mainly among the wasp-waisted Apocrita within the Hymenoptera, and in two othe ...
that is known for its mimicry of ants. The wingless females of ''G. agilis'' oviposit into ''D. coccinellae'' cocoons; the egg immediately hatches and consumes the developing wasp. Cocoons hosting ''G. agilis'' usually take twice as long to emerge.
Economic importance
Because one large aphidophagous ladybird can consume up to 5,500 aphid
Aphids are small sap-sucking insects and members of the superfamily Aphidoidea. Common names include greenfly and blackfly, although individuals within a species can vary widely in color. The group includes the fluffy white woolly aphids. A t ...
s in a year, any ladybird parasite represents a potential threat to agriculture.
References
External links
*
*
Photos of ''Dinocampus coccinellae'' by Bert Pijs
{{Taxonbar, from=Q1578772
Braconidae
Insects described in 1802
Mind-altering parasites