I hope you and Hap are both doing well and business good. I need some help with an offspring of our large Opuntia which has a white spoor like growth on it. The plant doesn’t seem to be hurt by it at all, but none the less I wanted to know what it is and what to do about it. Let me know if you have any knowledge or advice. As we need some small items I hope we can get up your way soon.
The Opuntia has a bad infestation of Scale Insects. They are sort of Limpet-like vampires of the pest world. You should be able to get rid of them, but it will take a bit of work. First, spray the branch down with straight rubbing alcohol (or Vodka) and then loosen them with an old paint brush, the alcohol will dissolve the shellack they coat themselves with when they glue down as adults. After doing what you can with the alcohol and paint brush, rinse with a “stern” jet of water from the hose, this will help blast off more them. Follow up with a good spray of Neem Oil at 1-2% solution, you can get this at any good nursery, as it is used on Roses as a natural insecticide and fungicide. Respray with Neem after a week at least three times to break the life-cycle of any hold outs or eggs that survive. Make sure to spray the Neem in the evening and not during the hot sun, as the oil needs time to disperse as to not cause burning of the plant. You should also fertilize that plant and give it an extra drink to boost it’s natural immunities.