By Jojanneke Bijkerk


A gall is an abnormal growth produced by the host organism  in response to the presence of another living organism . If the host is a plant, we call it a plant gall. The galls can be caused by animals (zoocecidia) and also by plants (phytocecidia) or fungi. The most familiair galls are caused by midges, wasps, mites and fungi, but gall-inducing organisms can be found in many more groups of organisms. This website will show you some of them. 



Contarinia craccae on tufted vetch, Vicia cracca

Please check out this about gall wasps:

development of knopper galls!!!



Published on 1 September 2009
Gallenboek, Fourth Edition




Does anybody know what species this is on Aster tripolium? See picture on the right...

Unidentified species of plant galls or other funny gall-like forms of life deserve some attention: go to unidentified species.






If you are interested in the fabulous nature of Belize, you can read about it in my diary on the Belize website:



News: Andricus aries found in different locations in the Netherlands.

Andricus aries in Thijssepark and Amsterdamse Bos November 2006

Andricus aries first found in the Netherlands in 2003 in Diemerpark

On Aster tripolium
(picture: Date Luterop)

Smicronyx jungermanniae, a weevil, on Cuscuta europea (greater dodder), 04.08.06 Gendt, opposite the Millingerwaard!

Gall on Monstera sp.?

Beautiful galls from Belize