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.