California Oak Galls Wasps in the family Cynipidae are gall inducers on plants, or inquilines of gall inducers (living inside the galls made by other cynipids). The data for the Texas observations on BugGuide is VERY limited. Diplolepis rosae, rose bedeguar gall. They may also develop as a response to infections by several kinds of fungi, bacteria, and viruses. Oak bullet gall are often found on bur and swamp white oaks where they can cause girdling and twig loss as well as attract numerous stinging insects. Gall Production Gall: An abnormal plant growth caused by the action of insects or other organisms. Found on the twigs of spruce trees, often Norway spruce. Pine-Oak Gall Rust (Eastern Gall Rust): The fungus Cronartium quercuum causes gall rust on approximately 25 to 30 species of pine and oak. These growths typically emerge at bud break in the early spring. Galls affecting leaves are seldom if ever a serious problem. Caused by a small wasp, they typically appear on the leaves of valley oak and California white oak. Inside the gall, there are a number of chambers, each housing a larva which eats its way out. Several small larvae may be found inside the swollen folds of the leaf. Charley Eiseman advises that galls on Texas oaks are largely understudied. Identify oak galls on your trees. Gall Production ... Oak Apple Galls. The adult female wasp lays single eggs in developing leaf buds. It was self-published in 1960 and has black-and-white photos. We have illustrated 12 of the most curious and colourful galls to look for. Texas Woolly Oak Galls. Adults emerge in June and July. Infection of oak causes small brown or yellowing areas on the leaves. There are a number of common oak species in California including both tree species and shrub species. These galls can be found between May and June where the female has laid her eggs in the leaf bud. In an effort to simplify the identification of woolly looking oak galls in Texas, I pulled this info from BugGuide. Galls affecting twigs, such as the gouty oak gall and horned oak gall, can be more serious. One of the most well-known is the common oak gall wasp (Cynips quercusfolii), which induces characteristic, 2-cm in diameter, spherical galls on the undersides of oak leaves. The oak apple gall wasp, Biorhiza pallida, is a tiny wasp that causes growths, or 'galls', on oak twigs. The majority of species occur on oak trees (Quercus sp.). Oak apple or oak gall is the common name for a large, round, vaguely apple-like gall commonly found on many species of oak.Oak apples range in size from 2 to 4 centimetres (1 to 2 in) in diameter and are caused by chemicals injected by the larva of certain kinds of gall wasp in the family Cynipidae. Galls range in size from 1 mm to 6 cm or more and come in many shapes and colors, as depicted on this page. Iron-gall Ink A permanent ink derived from oak galls. Galls are abnormal growths caused when another organism interferes with a plant’s cells. Jumping Oak Gall. Typically associated with conifers and pines, firs, or incense cedars. A related midge species causes the marginal folds or leaf pockets that can be found on red oak or pin oak. The galls start small and green, become larger and red by midsummer, and finally brown knuckle-sized "bullets" by summer's end. Most species of gall wasps live as gall-formers on oaks. Inside of each gall is an individual larva feeding. According to Bugguide, the on-line pamphlet, "Cynipid galls of the Southwest" by Lewis Hart Weld is the best source of info about SW galls, especially desert galls. On the underside of the leaves, yellow to orange powder (spores) is visible. Some galls form where insects or mites feed or lay eggs. Trees species: Black Oak (Quercus kelloggii) Found in hilly regions between 2,000 and 6,000 feet. Gall Insect Management Caused by the aphid Adelges abietis. It's just a first draft, so comments and suggestions are very welcome! Symptoms and Diagnosis Identification and Control .