It is some kind of scale insect, maybe the cottony cushion scale. Scale insects are not very vulnerable to poisons, since the actual insect is inside a protective shell.
NOTE: "Do not apply imidacloprid (Merit or Bayer Advanced Citrus Fruit and Vegetables) for cottony cushion scale control. Although imidacloprid has scale insects listed on the label, it doesnâ€™t kill cottony cushion scale. To make matters worse, imidacloprid is very toxic to vedalia beetles. The beetles are poisoned when they feed on cottony cushion scale that have ingested imidacloprid. Cottony cushion scale outbreaks have been observed following use of this insecticide because the vedalia beetles were removed and the insecticide didnâ€™t control the pest. [this article has other suggestions about managing this pest] "https://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7410.html
Your confidor IS imidacloprid, a neonicotinoid poison. It does not kill the scale insects, but it does kill the beneficial insects that might help control them and other beneficials such as honeybees and ladybugs. I did some reading about common garden poisons and summarized it here: https://www.helpfulgardener.com/forum/vi ... 11&t=57653
Along with honeybees and many beneficial insects, imidacloprid is toxic to many birds and freshwater crustaceans, and to earthworms. Neonicotinoids spread in the environment and have been detected in ground water, soils, soil biota, field margin plants, etc
For heavily infested branches as pictured, I would just clip the branch off and bag it and trash it. For what remains spray the insects (only, not the whole plant) with rubbing alcohol.