WHAT ARE GALL WASPS?
Gall wasp belongs to the family of Cynipidae and these insects are also called as Gall flies. Around 1300 species of gall wasps are found through out the world and this insect is very small with 1-8 millimeters long. These insects are usually red, black or yellow in color and the color varies on different species.
Gall wasp comes from the group of stinging wasps that parasite plants and around 600 species are seen in United States and Canada. Most of this species attack oak trees and specific tissues of host plant. There are some species that attack raspberry, blackberries and other species of rose family.
Life cycle
The life cycle of these wasp are complex and the life cycle produces two alternative forms. In certain species different type of galls are formed on different type of host plants. The reproduction of gall wasp takes place on two sex propagation in which a male is completely not used. It takes several years to complete the life cycle of a gall wasp.
During first generation the adult female will lay their eggs under the side of oak leaves and after that egg hatches to form larvae. The larvae forms galls in the veins of the leaves. When they form adult they again lay eggs inside the twigs and at last the second generation larvae create twig galls during summer or spring.
When the female insect lays egg the plant galls are developed. You can easily find galls on most part of the trees such as leaves, buds, branches and roots. Some other species of gall wasp lives in eucalyptus tree, maple trees and in many herbs.
Types of gall wasps
Most species of gall wasp can be seen on oak tree and one of the most common oak gall wasp are two centimeter in diameter with a spherical galls under the side of oak leaves.Citrus gall wasp - Citrus gall wasps are pest which are seen on various citrus trees such orange, lemon and grape fruit. They damage citrus tree by laying eggs inside the narrow stem. Citrus gall wasp has a black body with red tinted eyes that cover most of its head.
Wool -Sower gall wasp – This type of gall wasps appear on white oak tree during spring season. They don’t hurt the tree enough but sometimes wool sower gall wasp attack affects the growing condition of the tree. This gall wasp is about 1/8 inch long and they uses white oak tree for a host. The wasp attack leaves, branches, roots and flowers of the white oak tree.
Chest nut gall wasp- This wasp is seen on the chest nut trees in china. This gall wasp is also seen through out in United States and in New England. They lay eggs in chest nut shoots and this insect affect the shoot production and nut growth of the tree. The larvae of this insect feed the galls of the chest nut tree and this is creating serious problem in China and America.
