Simultaneously or selectively, nymphs and adults of Orthezia insignis used physiological age of the host-units, the relative sizes of sap pathways and the concentration of photosynthates to choose feeding and/or oviposition sites, depending on the state of the host plant. On the non-flowering plants, physiological age and relative sizes of pathways were the principal determinants, while on flowering food plants all the three criteria were used although the sink-photosynthate-concentration factor had a decidedly dominant influence on Orthezia than otherwise.
