''Druon ignotum'' is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

gall wasp Gall wasps, also traditionally called gallflies, are hymenopterans of the family Cynipidae in the wasp superfamily Cynipoidea. Their common name comes from the galls they induce on plants for larval development. About 1,300 species of this gene ...

in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Cynipidae Gall wasps, also wikt:gallfly#Usage notes, traditionally called gallflies, are hymenopterans of the family Cynipidae in the wasp superfamily Cynipoidea. Their common name comes from the galls they induce on plants for larval development. About 1 ...

Ecology and Life History

This species is widely distributed in central and eastern

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

Larvae A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect developmental biology, development such as insects, some arachnids, amphibians, or cnidarians typical ...

induce

galls Galls (from the Latin , 'oak-apple') or ''cecidia'' (from the Greek , anything gushing out) are a kind of swelling growth on the external tissues of plants. Plant galls are abnormal outgrowths of plant tissues, similar to benign tumors or wart ...

white oaks ''Quercus'' subgenus ''Quercus'' is one of the two subgenera into which the genus ''Quercus'' was divided in a 2017 classification (the other being subgenus ''Cerris''). It contains about 190 species divided among five sections. It may be called ...

, including

bur oak ''Quercus macrocarpa'', the bur oak or burr oak, is a species of oak tree native to eastern North America. It is in the white oak section, ''Quercus'' sect. ''Quercus'', and is also called mossycup oak, mossycup white oak, blue oak, or scrub ...

swamp white oak ''Quercus bicolor'', the swamp white oak, is a North American species of medium-sized trees in the beech family. It is a common element of America's north central and northeastern mixed forests. It can survive in a variety of habitats. It forms ...

overcup oak ''Quercus lyrata'', the overcup oak, is an oak in the white oak group (''Quercus'' sect. ''Quercus''). The common name, overcup oak, refers to its acorns that are mostly enclosed within the acorn cup. It is native to lowland wetlands in the east ...

, and

post oak ''Quercus stellata'', the post oak or iron oak, is a North American species of oak in the white oak section. It is a slow-growing oak that lives in dry areas on the edges of fields, tops of ridges, and also grows in poor soils, and is resistant ...

. Like many oak gall wasps, this species has two generations per year - one

asexual Asexual or Asexuals may refer to: *Asexual reproduction **Asexual reproduction in starfish *Asexuality, the lack of sexual attraction to anyone or lack of interest in or desire for sexual activity. **Gray asexuality, the spectrum between asexualit ...

(or agamic) and one sexual, with each generation producing distinct galls. Galls of the agamic generation are small, ovoid, and occur in clusters along veins on the underside of leaves. They are covered by woolly cream- or pink-colored hair that becomes brown over the winter and sometimes wears away. Females emerge from these galls early in spring and

oviposit 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 ...

in the buds of host oak trees. This induces the galls of the sexual generation, which are small ovoid cells within buds and young shoots; they cause little or no externally visible deformity. Both male and female adult wasps emerge from these galls and mate, with mated females then ovipositing on the underside of oak leaves, inducing the galls of the agamic generation.

Taxonomy

This species was first described by

Homer Franklin Bassett Homer Franklin Bassett (September 2, 1826 – June 28, 1902) was an American hymenoptera, hymenopterist specializing in gall wasps. In addition, he was the librarian of Silas Bronson Library in Waterbury, Connecticut. Early life and education ...

as ''Cynips ignota'' in 1881 and has been included in various genera before its recent placement in '' Druon''.

References

External links

* * {{Taxonbar, from=Q113110634 Cynipidae Gall-inducing insects Oak galls Taxa named by Homer Franklin Bassett Insects described in 1881 Hymenoptera of North America