Resource Guide for Organic Insect and Disease ... - Cornell University

164 Organic Resource Guide
accurately measure the required amount of Entrust SC, a graduated cylinder is required, allowing
measurements of volumes to the nearest one-tenth of a milliliter. Alternatively, a scale can
be used to measure weights to the nearest one-tenth of a gram. Mixing only as much spray as
needed for a single treatment is recommended. Do not use more than 3 gallons of spray per
1000 sq ft of area. Follow all other label instructions for mixing and application.
milliliters (mL) or grams (g)
Entrust SC, per gallon per 3 gallons of per 5 gallons
fl oz/acre of spray spray or 1000 sq ft of spray
2 0.5 1.4 2.3
3 0.7 2.0 3.4
4 0.9 2.7 4.5
5 1.1 3.4 5.7
6 1.4 4.1 6.8
7 1.6 4.8 7.9
8 1.8 5.4 9.1
9 2.0 6.1 10.2
10 2.3 6.8 11.3
According to the manufacturer, the rate of 7 fluid ounces per acre is equivalent to 1 teaspoon
per 1,000 square feet. Dow. (2012)
Studies have shown that some populations of the diamondback moth have developed resistance
when Entrust is used intensively (Zhao et al. 2002), so resistance management should
be practiced. Avoid applications of Entrust on consecutive pest generations. Alternate sprays
with other effective products, and implement cultural controls. The Entrust label has detailed
instructions for resistance management.
Many crops have maximum yearly application restrictions. See the label for specific information.
REENTRY INTERVAL (REI): 4 hours.
EFFECTS ON THE ENVIRONMENT
Leaf persistence: Spinosad is partly taken up by leaf tissue, which enhances its effectiveness
over time. Dry surface residues do little harm to non-plant feeding insects. Spinosad residues
on the leaf surface are broken down by sunlight. Half-lives for spinosyn A are 1.6 to 16 days,
depending on the amount of sunlight received (Saunders & Brett 1997).
Fate in water: When spinosad is mixed with water, very little breakdown (hydrolysis) occurs;
however, in water exposed to sunlight, photodegradation occurs rapidly (Saunders & Brett
1997). In the absence of sunlight, the half lives of spinosyn A and D are at least 200 days.
Soil Persistence: Soil microbes degrade spinosad into other spinosyns that can persist in the
soil for several months and remain biologically active. Repeated applications could lead to
some build-up of spinosyns in soil. A 10-month field study in California and Mississippi showed
that no degradation products were found in soil below 24 inches (Saunders & Brett 1997).
Leaching: Spinosyn A is more water-soluble than spinosyn D; therefore, it was the subject of
soil mobility studies. Research showed that spinosyn A and its soil metabolites bind to soil and
have low soil mobility.
Wildlife: Spinosad shows slight toxicity to birds, moderate toxicity to fish, and slight to moderate
toxicity to aquatic invertebrates. In laboratory tests, it was highly toxic to bees, oysters (US
EPA 1997 a,b), and other marine mollusks (Dow 2001).