Posted by Nosferatumyia on 09-07-2012 15:48
#6
The fly could emerge from a seed brought on pants or dog's tail and then find a flower head more or less fitting it needed. Or a burdock was here the last year only and now is just a rosette.
Terellia tussilaginis follows always AFTER
Tephritis bardanae phenologically, as it needs fully grown flower heads rather than half-sized buds (as
T. b. does)