This is the week to begin managing SJS crawlers emerging from the female covering. Use a two application program at 10-14d intervals beginning at the first available window.
Over the past five years the San Jose scale (SJS) has become one of the most damaging of insects in tree fruit. In part, it’s due to the time of year when crawler emergence is combined with Codling Moth and Obliquebanded Leafroller emergence. The materials we now employ for lepidopteran pests (Delegate, Altacor, Proclaim, Intrepid, Granulosis virus, mating disruption and Bt) are relatively ineffective against the SJS. Whereas, in years past, up through the early 1990’s, Penncap-M and Lorsban, used against the OBLR, also controlled the SJS during this window of internal and leafroller management.
Most growers with a few fruit infested with SJS in year one, turn into bushels of infested fruit by year 2, quickly followed by whole blocks with bins of damaged fruit by year three. If you had a single tree infested last season with SJS over the packing line, it’s time to weigh in hard on scale this week!
Using degree days accumulations from the first flight of the male AND historical mean data calls for San Jose scale (SJS) crawler emergence will occur on or after the 16th of June. If you had SJS on your fruit last season AND did not make applications against this insect during the pre-bloom or early post-bloom period, the window for applying an effective insecticide begins this week. Choices are available for SJS management include Admire Pro 4.6SC at (2.8 fl.oz./A) a feeding toxicant, Assail 30SG (8.0 oz./A) a translaminar feeding and contact insecticide, Centaur 0.7WDG (34.5 oz./A) and Esteem 35WP (4-5 oz./A) insect growth regulators; Imidan 70WP 70WS (2.13-5.75 lb./A), contact insecticide; the pre-mix insecticides Endigo ZC (5-6 fl.oz./A), Leverage 360 (2.4-2.8 fl.oz./A) and Voliam Xpress EC (6-12 fl.oz./A) include contact and feeding activity.
A two week window is needed for Movento to be effective. If you’re trying to clean up a robust population, Movento PLUS OIL or a penitratnt such as LI700 at a penetrating rate should be applied with a contact insecticide.