Mediterranean Fruit Fly Control on Persimmon, 1991

The study was conducted at a 50-yr-old persimmon orchard in Kula, Hawaii. Thirty trees were used; 15 for treatment and 15 for control. Sprays were applied to bearing trees prior to first harvest and continuing weekly throughout the harvest period to control MFF. Application dates were as follows: 18 and 25 Sep; 2, 9, 16, 23, and 30 Oct; 6, 13, 20, and 27 Nov. Sprays were applied with a CO2-pressurized backpack sprayer at 30 psi with a single nozzle generating large droplets. Each tree received 100 ml of spray (25 liters/ha), 2.0 mg Al/ml. The spray was directed at the underside of foliage on each tree. Control trees were not sprayed. All mature persimmon fruits on each tree were harvested weekly. Harvest dates were as follows: 10, 15, 22, and 29 Oct; 5, 12, 19, and 26 Nov; 3 Dec. Efficacy of sprays was evaluated weekly at harvest by sorting the harvested fruit from each tree into the following categories: (a) marketable fruit; (b) fruit fly stung fruit; and (c) unmarketable fruit with damage by other factors (minor insect pests, disease etc.). Fruits in each category were counted.