Commercial growers often spray at night, to avoid the high temperature problems. Trees are just fine even if it is 95 or higher the following afternoon.

I did not realize that there was a problem with application at high temperature. That could be the problem causing the leaf drop on my mandarin, although I have been applying in the afternoon.

--- Skeet

Oil just discourages the leaf miner from laying eggs. It doesn't kill the miner. I use a summer rate of dormant oil with spinosad all summer long to keep off the scale and whitefly. Kills the dredded leaf footed bugs as well.

I have not been able to find Sunspray ultra fine oil at any of my local sources so I tried the internet and found that it was no longer available from the manufacturer. Looks like you can order it in large quantities but the pint and quart sizes are not available.
Here’s the link http://www.groworganic.com/item_POP806_SunsprayUltraFineOilQuart.html
What would be a good alternative?
Karl

I am a chemical engineer in an oil refinery. It is interesting that the hort oil in Florida is 435 mid boiling point as that is in the kerosene atmospheric pressure boiling range and actually close to the heavier end of gasoline! Gasoline endpoint can be around 400F or so. Perhaps it is 435F in a vacuum distillation? Kerosene atmosperic pressure boiling range is 380F to 550F or so. We used to make hort oil in our refinery to be shipped off to central america for the banana crop. The banana oil has am atmospheric boiling range in excess of 650F and distilled off as the top cut on our crude vacuum tower. My 5 gallon can of dormant oil doesn't list a boiling point.

I found that buying dormant oil from an ag store in 2.5 or 5 gallon can was much cheaper. 2.5 gallons was cheaper than a gallon at the big box stores.