Figure 1 Life cycle diagram of Schlechtendalia chinensis
A typical life cycle of the horned gall aphid in Hubei, China. A
fundatrix (1) finds a suitable tender leaf on the primary hostRhus chinensis , to feed and initialize gall formation, and feeds
inside the induced gall by the end of April or the beginning of May.
Afterwards, the fundatrix and the wingless daughters (called
fundatrigeniae) (2) reproduce for generations viviparously and
parthenogenetically within the gall from May to October. The gall size
increases gradually along with the growth of the aphid population in it.
At the end of October, winged autumn migrants (3) emerge from the gall
and fly away after the gall opened. The migrants find the mossPlagiomnium maximoviczii nearby where they produce nymphal
offspring. (4) The nymphs feed on the moss and secrete waxes to wrap
themselves up for overwintering. Winged spring migrants (5) emerge by
the end of March, then fly back to the primary host and reproduce sexual
females (6) and males (7) in the trunk crevices. After mating, the
female reproduces a fundatrix to begin the next life cycle. * Graphs not
in scale. Stippled sector indicating the in-gall stages.