For a soil drench application to a tree that's 48 inches DBH, you may uniformly apply a 1.6 oz packet of Zenith 75 WSP Insecticide in no less than 10 gallons of water per 1,000 square feet around the base of the tree, directed to the root zone.
Zenith 75 WSP Insecticide can take up to 8 weeks to translocate throughout a plant/tree and begin to work. It should be applied before the target pest is actively feeding for best results.
Zenith 75 WSP Insecticide is labeled for eradication of thrips for a foliar application as listed. It does not specifically mention the species.
If you have not purchased Zenith 75 WSP Insecticide yet, please note that you must mix up large batches at a time that will require at least a 25 gallon tank to mix up one packet. If you have not purchased the Zenith and you do not have a way to make large tank mixes, then you may want to purchase the Dominion 2L which will allow you to mix very small or large quantities depending on your needs and abilities. For grubs, you should apply 0.6 oz. per 1000 square feet in at least 1 gallon of water.