''Druon ignotum'' is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

gall wasp Gall wasps, also incorrectly 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 gener ...

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 ...

Cynipidae Gall wasps, also incorrectly 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 gener ...

Ecology and Life History

This species is widely distributed in central and eastern North America. Larvae 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, fungi, or animals. Plant galls are abnormal outgrowths of plant tissues, similar to be ...

white oaks The genus ''Quercus'' contains about 500 species, some of which are listed here. The genus, as is the case with many large genera, is divided into subgenera and sections. Traditionally, the genus ''Quercus'' was divided into the two subgenera '' ...

, 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 o ...

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, 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 also grows in poor soils, and is resistant to r ...

. Like many oak gall wasps, this species has two generations per year - one asexual (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 hymenopterist specializing in gall wasps. In addition, he was the librarian of Silas Bronson Library in Waterbury, Connecticut. Early life and education Bassett was ...

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