An abnormal growth (often a swelling) of plant tissue, caused by external stimuli, generally by insects such as gall wasps (Cynipidae), and gall midges (Cecidomyidae) but also by mites, aphids, psyliids and some Lepidoptera. Sometimes galls are formed by bacteria, parasitic fungi or other diseases of the plant so galls induced by insects are called insect galls.
Links: http://en.wikiped.../wiki/Gall
Some flies preserved in ethanol and then pinned often get the eyes sunken, how can this be avoided? Best answer: I usually keep alcohol-collected material in alcohol
Tried to attach an image to a forum post. jpg, 32kB, 72dpi, no blanks, ... File name is correctly displayed, but when I click "Preview Thread" it just vanishes. Help!