Abstract  [Aim]  To determine the effect of food deprivation on the predatory behavior of the ladybird, Harmonia axyridis, on two different walnut aphids, Chromaphis juglandicola and Panaphis juglandis. [Methods]  The predatory behavior of adult H. axyridis after different levels of food deprivation was observed in a laboratory and the average time required to complete each stage of the predation process, and the number of aphids consumed, were measured. [Results]  Predatory behavior had six stages: Searching, feeding, grooming, resting, vibrating wings and excreting. The proportion of time consumed by each stage could be ranked as follows: Resting > searching > grooming > feeding > vibrating wings > excreting. Compared to the control group which had constant access to food, H. axyridis that had been subject to 24 h of food deprivation spent 45.18% more time preying on C. juglandicola and 62.09% more time preying on P. juglandis. Food deprivation increased the number of C. juglandicola consumed from 87.5 to 132.9, and the number of P. juglandis from 52.5 to 104.5. The average time required for a ladybird to consume one C. juglandicola was 13.10-13.61 seconds, compared to 40.21-48.94 seconds for one C. juglandicola. [Conclusion]  Food deprivation and prey species have significant effects on the predatory behavior of H. axyridis adults.