''Copidosoma'' is a genus of chalcid wasps, which are

parasitoids In evolutionary ecology, a parasitoid is an organism that lives in close association with its host at the host's expense, eventually resulting in the death of the host. Parasitoidism is one of six major evolutionary strategies within parasi ...

of Lepidoptera. The wasps are

polyembryonic Polyembryony is the phenomenon of two or more embryos developing from a single fertilized egg. Due to the embryos resulting from the same egg, the embryos are identical to one another, but are genetically diverse from the parents. The genetic differ ...

, depositing one or two eggs into their host which then develop into multiple offspring and have a soldier caste and a reproductive caste.

Species and biology

''Copidosoma'' has over 200 species, according to the Natural History Museum of London's Universal Chalcidoidea Database. Among these is ''

Copidosoma floridanum ''Copidosoma floridanum'' is a species of wasp in the family Encyrtidae which is primarily a parasitoid of moths in the subfamily Plusiinae. It has the largest recorded brood of any parasitoidal insect, at 3,055 individuals. The life cycle begins ...

'', known for having the largest recorded brood of any parasitoidal insect, at 3,055 individuals, and for having its genome sequenced by the

Human Genome Sequencing Center The Baylor College of Medicine Human Genome Sequencing Center (BCM-HGSC) was established by Richard Gibbs (biologist), Richard A. Gibbs in 1996 when Baylor College of Medicine was chosen as one of six worldwide sites to complete the final phase of t ...

as part of the i5K project. They are mainly

parasitoids of the caterpillars of Lepidoptera and have been deliberately introduced into many areas as biological control agents for agricultural pests, e.g. ''Copidosoma floridanum'' was introduced to

Hawaii Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only state ...

to control the tomato looper ('' Chrysodeixis chalcites'') while '' Copidosoma koehleri'' is used extensively in control of the potato tuber moth (''

Phthorimaea operculella ''Phthorimaea operculella'', also known as the potato tuber moth or tobacco splitworm, is a moth of the family Gelechiidae. It is an oligophagous insect that feeds on the plant family Solanaceae and is especially known for being a major pest of ...

'') and '' Copidosoma primulum'' has been used in China to control the cotton bollworm ('' Helicoverpa armigera'') in wheat crops. The wasps of the genus ''Copidosoma'' are also of interest because they are polyembryonic, i.e. more than one embryo can be found in a single egg, and they have developed a caste system where an embryo can develop into a reproductive adult or a soldier caste. The wasp lays its egg into the host moth's egg and after the caterpillar hatches it undergoes a number of

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 ...

stages until it reaches its final instar and during this time the wasp's egg produces as many as 3000 embryos through cloning, these form an assemblage called a polymorula and live as endoparasitoids in the host. In a study on ''C. floridanum'' 24% of the members in the polymorula, of either sex, develop in to soldiers and when the host is killed in its final instar these soldiers die too while their siblings consume the host and pupate to emerge as adults around two weeks later. Like other Hymenoptera the females are produced from fertilised eggs and the males from unfertilised eggs, female eggs produce a higher number of soldiers throughout development while male eggs produce fewer and only in the later stages of the cycle. Where there is more than one brood, where more than one egg has been laid in a host the soldier caste from the first female brood will kill all any larvae from subsequent eggs laid, except that if a male brood is older and from a different mother then the females will co-exist with the males. It appears that the early emerging female soldiers purpose is inter-specific competition, they ensure that the first female brood has the host to themselves by killing other non related and females and related and younger males, while the later soldiers are produced to defend the host from intra-specific competitors and are produced by both sexes, although male soldiers of ''C. floridanum'' lack aggression and their production may be a trait which is being selected against. Most species of this genus are quite host specific and use a few species of moth as their hosts and phylogenetic analysis indicates that the more closely related the species of wasp are to one another the more similar the species of host selected tend to be. For example the wasps of the species group named after '' Copidosoma cervius'' are all parasitoids of moths in the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Geometridae The geometer moths are moths belonging to the family Geometridae of the insect order Lepidoptera, the moths and butterflies. Their scientific name derives from the Ancient Greek ''geo'' γεω (derivative form of or "the earth"), and ''metro ...

while those in the ''nacoliae'' species group attack caterpillars of the families

Pyralidae The Pyralidae, commonly called pyralid moths, snout moths or grass moths, are a family of Lepidoptera in the ditrysian superfamily Pyraloidea. In many (particularly older) classifications, the grass moths (Crambidae) are included in the Pyralida ...

and

Tortricidae The Tortricidae are a family of moths, commonly known as tortrix moths or leafroller moths, in the order Lepidoptera. This large family has over 11,000 species described, and is the sole member of the superfamily Tortricoidea, although the genus ...

Others of note

* '' Copidosoma thebe'' (Walker, 1838) senior synonym of ''Litomastix claviger'' Mercet, 1921

Species and biology

Others of note

Species

References

External links