Gall Facts for Kids

The red things are galls produced by a gall mite on a leaf

Gall produced by an insect on a vine

Galls can also appear on skeletal animals and in the fossil record. Two galls with perforations on a crinoid stem from the Middle Jurassic of southern Israel

Oak apple or oak gall is a large, round, gall commonly found on species of oak, 2–5 cm in diameter. They are caused by chemicals injected by the larva of certain kinds of gall wasp in the family Cynipidae

Galls are growths on the surface of plants and other lifeforms. They are caused by various parasites, such as fungi, bacteria, insects and mites.

Plant galls are abnormal growths of plant tissues similar to benign tumors or warts in animals.

What causes a plant gall can often be known without the actual agent being there. Many types of gall have typical structures. This is true of many galls produced by insects and mites.

Insect galls on plants give some herbivorous insects their own microhabitat. They are plant tissue which is controlled by the insect. Galls are the habitat and food source for the maker of the gall. The gall may contain nutritious starch and other tissues. Galls often give the insect physical protection from predators.

Insect galls are usually induced by chemicals injected by the larvae or the adults of the insects into the plants, and possibly by mechanical damage. After the galls are formed, the larvae develop inside until fully grown, when they leave. In order to form galls, the insects must seize the time when plant cell division occurs quickly. The growing season, usually spring in temperate climates, is longer in the tropics.

Gallery

Gall on a Maple leaf
Rose bedeguar gall on a wild rose in summer.
Neuroterus albipes forma laeviusculus
Eucalyptus leaf gall
Cola-nut galls on Pedunculate Oak
Gymnosporangium
Oak marble galls, one with a Gall fly exit hole and another with Phoma gallorum fungal attack.
Pineapple gall on Sitka spruce.

Images for kids

A crown gall on Kalanchoe infected with Agrobacterium tumefaciens.
Gall from a Jade Plant (Crassula ovata)
Sectioned oak marble gall showing central "cell", inquiline chamber, and exit-hole with a possibly parasitised stunted gall specimen.
Goldenrod round gall made by the fly Eurosta solidaginis
Galls caused by an Eriophyid mite (Eriophyidae) on Banksia integrifolia infructescence in Melbourne, Australia
Rhododendron ferrugineum infected by an Exobasidium fungus.
Oak artichoke gall (Andricus fecundator)
Knopper gall (Andricus quercuscalicis)
Knopper gall (Andricus quercuscalicis)
Andricus kollari oak gall
Andricus kollari oak gall
Red-pea gall (Cynips divisa) on pedunculate oak
An oak tree with multiple oak apples
Oak apples on an oak tree
Lime nail galls (Eriophyes tiliae tiliae)
Leaf galls on Rhododendron ferrugineum
Dasineura investita nettle gall
Schizomyia impatientis jewelweed flower gall
Pachypsylla celtidisumbilicus hackberry gall
Neolasioptera boehmeriae false nettle stem gall
Kokkocynips rileyi oak gall
Phylloteras poculum oak galls
Gall on peach tree leaves
Eucalyptus cypellocarpa at The Gap Scenic Reserve, Australia
Gall attack on Eucalyptus due to Leptocybe invasa at Acharya N. G. Ranga Agricultural University
Fruit gall on Actinidia polygama

Gall facts for kids

Gallery

Images for kids

See also