Gall-inducing insect
Encyclopedia
A gall-inducing insect is any insect that can cause the growth of gall
within plant
s. The term gall fly is also used to cover these species, although most are not true flies.
There are several groups of insects that meet this description. They include the gall wasp
s, scale
s, gall midges, aphid
s, and psyllids.
Galls are growth deformities induced in certain plants by various insects which are mostly species-specific.
The gall's form or type depends on what organism is attacking the plant and where the plant is being attacked.
Based on the form there are two classification systems used to identify the cause of galls. Causitive agents located outside plant tissues, and those agents located inside plant tissues.
Causitive outside agents include:
Krebs gall is caused by surface agents.
Filz gall is caused by agents among surface hairs.
Fold/roll gall is caused by agents within turned-over leaf blades.
Pouch gall is caused by agents within a cuplike structure that occurs when opposite ends of the infected structure arch upward and form a spherical oval.
Causitive inside agents include:
Covering gall is caused by agents embedded within a gall when plant tissues rise up and surround the parasite.
Lysenchyme gall is caused by agents that sink into the plant when the plant cells dissolve away and close around the parasite.
Mark gall is caused by agents burrowing within plant tissue before gall develops.
This symbiotic relationship is rather one sided, whereas not a lot of research has been done to verify any benefit given to the plant species. The insect who causes the gall formation gets an entire microenvironment or microhabitat provided to it. Safe from climate and predation to grown within, and with a rich nutrient formed within the gall for the parasitic insect to feed upon.
Gall
Galls or cecidia are outgrowths on the surface of lifeforms caused by invasion by other lifeforms, such as parasites or bacterial infection. Plant galls are abnormal outgrowths of plant tissues and can be caused by various parasites, from fungi and bacteria, to insects and mites...
within plant
Plant
Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or...
s. The term gall fly is also used to cover these species, although most are not true flies.
There are several groups of insects that meet this description. They include the gall wasp
Gall wasp
Gall wasps , also called Gallflies, are a family of the order Hymenoptera and are classified with the Apocrita suborder of wasps in the superfamily Cynipoidea...
s, scale
Scale insect
The scale insects are small insects of the order Hemiptera, generally classified as the superfamily Coccoidea. There are about 8,000 species of scale insects.-Ecology:...
s, gall midges, aphid
Aphid
Aphids, also known as plant lice and in Britain and the Commonwealth as greenflies, blackflies or whiteflies, are small sap sucking insects, and members of the superfamily Aphidoidea. Aphids are among the most destructive insect pests on cultivated plants in temperate regions...
s, and psyllids.
Galls are growth deformities induced in certain plants by various insects which are mostly species-specific.
The gall's form or type depends on what organism is attacking the plant and where the plant is being attacked.
Based on the form there are two classification systems used to identify the cause of galls. Causitive agents located outside plant tissues, and those agents located inside plant tissues.
Causitive outside agents include:
Krebs gall is caused by surface agents.
Filz gall is caused by agents among surface hairs.
Fold/roll gall is caused by agents within turned-over leaf blades.
Pouch gall is caused by agents within a cuplike structure that occurs when opposite ends of the infected structure arch upward and form a spherical oval.
Causitive inside agents include:
Covering gall is caused by agents embedded within a gall when plant tissues rise up and surround the parasite.
Lysenchyme gall is caused by agents that sink into the plant when the plant cells dissolve away and close around the parasite.
Mark gall is caused by agents burrowing within plant tissue before gall develops.
This symbiotic relationship is rather one sided, whereas not a lot of research has been done to verify any benefit given to the plant species. The insect who causes the gall formation gets an entire microenvironment or microhabitat provided to it. Safe from climate and predation to grown within, and with a rich nutrient formed within the gall for the parasitic insect to feed upon.
Further reading
- Darlington, Arnold (1975) The Pocket Encyclopaedia of Plant Galls in Colour. Pub. Blandford Press. Poole. ISBN 0-7137-0748-8.