Sexual dichronism and intersexual phoresy in gall-forming coccoids

Summary Coccoid gall-formers from the genus Cystococcus exhibit sexual dichronism, producing the males of a brood well before their sisters. This ensures the coexistence in the maternal gall of winged adult males and their first instar wingless sisters. Females disperse by clinging to the attenuate abdomens of their brothers, and the efficiency of this dispersal is reflected in an even dispersion on host trees. Evolution of this form of phoresy may be associated with the paternal genome loss prevalent in the Coccoidea.