The gall of plant diseases [Cecidium]
Definition of gall of plant diseases or cecidium
A gall or cecidium is usually defined as an abnormal plant over growth caused by the parasitic plant or animal.
Types of gall of plant diseases or cecidium
▲ Phytocecidium: Caused by parasitic plant.
▲ Zoocecidium: Caused by animal. Gall forming mites and insect Mites Acarus, Eriophyes, Phyllocoptes. Insect
▲ Hymenoptera: Cynipidae (Gall wasps).
▲ Diptera: Agromyzidae (greenflies, blackflies or whiteflies), Tephritoidea (gall flies), Cecidomyiidae (gall midges), Chloropidae (grass flies).
▲ Homoptera: Aphididae (Chinese sumac aphid), Coccoidea (Scale insect), Psyllidae (Jumping plant lice).
▲ Besides, a few member of the Coleoptera and Lepidoptera can also produce gall. How insect produce gall
Gall insect → Immature stage → Stimulating substance → Stimulated host tissue → Over growth → Gall.
Example: Rice gall midge and Onion shoot of rice.