Phanacis taraxaci (Ashmead, 1897)

Nomenclature: Gillettea taraxaci Ashmead, 1897

Feeds on: Induces galls on Taraxacum officinale F. H. Wigg.

Distribution: United States: Minnesota, Pennsylvania

Gillettea taraxaci

Fusiform enlargements of petiole, along midrib or at base of peduncle. An European species on an introduced European host plant, Taraxacum officinale.

[Photo caption]

343. On wild dandelion, Taraxacum officinale. Green and fleshy in June, becoming brown and pithy later. The maker emerged the next spring.

Phanacis taraxaci
Dandelion gall wasp

Host: Dandelion (Taraxacum officinale).

Gall location: On the leaf, often extending from the very base of the leaf all the way up the petiole and midrib.

Description: Spherical to oval-shaped, blister-like, single-chambered galls, often only a few millimeters in length. Typically quite abundant, and sometimes with multiple adjacent galls clustered together or otherwise confluent.

Range: Dandelions are found throughout North America, but thus far, this gall has only been observed in a handful of northern states and provinces, including Pennsylvania, Michigan, Minnesota, Oregon, Quebec, and Saskatchewan. These galls certainly exist elsewhere within the range of the host plant.

This species was introduced to North America from Europe along with its host plant. Interestingly, this gall was first described in North America prior to its discovery in Europe. Because dandelions are often considered weeds and are frequently culled, this gall generally appears to be more common in areas that are not actively maintained.

The dandelion gall wasp and the catsear gall wasp (Phanacis hypochoeridis), both of which are introduced species, are the only representatives of the gall wasp tribe Phanacidini to be found in North America.

on Taraxacum

GALL
2-4 mm large, hard, unilocular swellings of the midrib, smooth and often red in colour. Often they are aggregated, into masses of upto 3 cm long and a cm thick. This happens in particular in the pedicel, that locally may develop into a sausage-like gall.

HOST PLANTS
Asteraceae, monophagous
Taraxacum officinale.

[click link below for photos]

Aylax taraxaci (Ashmead)

Gillettea taraxaci Ashmead
Aulax taraxaci

Gall. (Plate XIV, Fig. 8.) Along and surrounding the petiole or midrib of the leaf of the common dandelion (Taraxacum taraxacum). Polythalamous. Pithy, irregular, oblong swellings, usually composed of knottv swellings and occurring together and forming, oblong irregular galls. Length 25-50 mm.

Habitat. Minnesota (Winona); New York; Canada (Ontario).