The Ditrysia are a natural group or
clade of
insect
Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (head, thorax and abdomen), three pairs ...
s in the
lepidopteran
order
Order, ORDER or Orders may refer to:
* Categorization, the process in which ideas and objects are recognized, differentiated, and understood
* Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of d ...
containing both
butterflies
Butterflies are insects in the macrolepidopteran clade Rhopalocera from the order Lepidoptera, which also includes moths. Adult butterflies have large, often brightly coloured wings, and conspicuous, fluttering flight. The group comprises t ...
and
moth
Moths are a paraphyletic group of insects that includes all members of the order Lepidoptera that are not butterflies, with moths making up the vast majority of the order. There are thought to be approximately 160,000 species of moth, many of ...
s. They are so named because the female has two distinct sexual openings: one for
mating
In biology, mating is the pairing of either opposite- sex or hermaphroditic organisms for the purposes of sexual reproduction. ''Fertilization'' is the fusion of two gametes. '' Copulation'' is the union of the sex organs of two sexually rep ...
, and the other for laying
eggs (in contrast to the
Monotrysia).
About 98% of
described species of Lepidoptera belong to Ditrysia. As larvae, they initially feed on plants until they grow to become adults and feed on nectar. Distrysian lineage by the ones that live and cater from the host plant, or even the ones that live outside the plant constructing their own shelter. They function as herbivores, pollinators, and prey in terrestrial ecosystems, while also being extremely damaging to the development of agriculture. The Lepidoptera group can be divided into the primitive but
paraphyletic
In taxonomy (general), taxonomy, a group is paraphyletic if it consists of the group's most recent common ancestor, last common ancestor and most of its descendants, excluding a few Monophyly, monophyletic subgroups. The group is said to be pa ...
"micromoths" and the derived
monophyletic
In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic ...
Apoditrysia, which include mostly larger moths, as well as the butterflies. Those with a dorsal heart vessel belong in section
Cossina
Cossina is the name for both a section and subsection of Ditrysian insects in the order containing both butterflies and moths having a dorsal heart vessel. The section named Cossina contains two subsections: one also named Cossina (containing mo ...
. Others, having a ventral heart vessel, belong in section Tineina. While it is difficult to pinpoint the origin of affinities between clades, Tineoidea are found to be useful in understanding the vast diversity in Ditrysia. Obstecomera and Macrolepidoptera are other examples of Ditrysia's subclades. Apoditrysia, Obtectomera, and Macrolepidoptera will be considered monophyletic if one or more organisms are either included or excluded from the clade.
See also
*
Lepidoptera
*
Taxonomy of Lepidoptera
The insect order Lepidoptera consists of moths (43 superfamilies), most of which are night-flying, and a derived group, mainly day-flying, called butterflies (superfamily Papilionoidea). Within Lepidoptera as a whole, the groups listed below bef ...
References
Further reading
*
*
External links
Tree of Life project page: Ditrysia*
Protostome unranked clades
{{Ditrysia-stub