Spirodiclofen

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Chemical Identification | General Product Information | Physical & Safety Data

Chemical Identification

Common Name

Spirodiclofen

中文通用名

螺螨酯

IUPAC

3-(2,4-dichlorophenyl)-2-oxo-1-oxaspiro[4.5]dec-3-en-4-yl 2,2-dimethylbutyrate

CAS

3-(2,4-dichlorophenyl)-2-oxo-1-oxaspiro[4.5]dec-3-en-4-yl 2,2-dimethylbutanoate

CAS No.

148477-71-8

Molecular Formula

C₂₁H₂₄Cl₂O₄

Molecular Structure

General Product Information

Category

Acaricides / Miticides > Tetronic acid acaricides

Activity

Acaricide/Miticide
Spirodiclofen is active against the eggs, larvae, nymphs, all quiescent stages and adult females of mites. It targets lipid metabolism, affecting the production of energy by the mite. It is used in the range 50 to 200 g ai/1000L. One application per season is recommended to avoid development of mite resistance, following IRAC guidelines.

In field trials, the initial activity of spirodiclofen is less than that of fast acting products such as acequinocyl or pyridaben but it is significantly faster acting than hexythiazox or etoxazole. The activity of spirodiclofen is largely unaffected by extremes of temperature and rainfall; spirodiclofen adheres to the waxy cuticle of the plant and cannot be washed off by rain. The residual action is around 6 weeks. It can be used in IPM-programmes as it is harmless to beneficials, and in resistance management programmes.

In pome fruit, the efficacy of spirodiclofen is less temperature dependent than the current reference, amitraz, and the long residual activity enables it to protect flowers, fruitlets and shoots over most of the pear sucker infestation period. When applied at the early stage of development of pear sucker nymphs (when mature eggs are close to hatching), spirodiclofen provides good control of L1-L3 larvae on the flower clusters and shoot tips and inhibits or disrupts further development to the L4-L5 instars. Scale insects are best controlled by an application when the scale crawlers begin to migrate. Spirodiclofen does not produce adverse effects in Anthocoridae and other important natural predators in pears.

In field trials in Peru in 2002, spirodiclofen provided good control of red spider mites in a commercial plantation on mandarin oranges. In Brazil, Envidor will be developed for the control of: Brevipalpus phoenicis, Polyphagotarsonemus latus, Phyllocoptruta oleivora and Panonychus citri on citrus; B phoenicis and Oligonychus ilicis on coffee; Aceria guerreronis on coconuts; Aculops lycopersici on tomatoes; Tenuipalpus hevea on rubber trees; P latus on papaya and Panonychus ulmion apples.

Field trials in Poland in 1999-2001 (ISHS Acta Horticulturae) confirmed the potential for control of two-spotted mites (T urticae) on blackcurrant plantations. Envidor 240SC was applied just after flowering and just after fruit harvest and gave control equivalent to the commercial standards (fenazaquin, propargite, fenpyroximate) with a residual action of 2-6 weeks.

The US has the second largest citrus growing area (440,000 ha in 2002) in the world, with orange the dominant species (331,000 ha). Grapefruit is grown on around 62,000 ha. Phyllocoptruta oleivora is the major mite target across the citrus segments. Field trials in citrus in Florida from 1996-2001 with Envidor 240SC (175-350 g ai/ha, with or without spray oil) demonstrated that spirodiclofen provided good control at 52 days after application of pink citrus mite (Aculops pelekassi) and citrus rust mite (P oleivora), superior to the control provided by avermectin. Consequently, Envidor will be developed in the oil-based spray market (summer) and the non-oil (spring / fall) market. It was shown to be compatible in tank mixes with Kocide 2000, the most common copper fungicide treatment.

Field trials in lemon groves in California showed that Envidor plus oil could provide control of citrus budmite (Eryophyes sheldoni) to 36 DAT. There also appears to be potential for the control of California red scale (Aonidiella aurantii).

Almonds: trials in the US showed Envidor to be superior to propargite and equivalent or superior to avermectin for the control of the brown mite, Bryobia rubrioculus.

Field trials evaluated the use of Envidor on apples in Nova Scotia from 1998 to 2001, and on apple, pear, peaches and grapes in Ontario in 2001. The product was found to provide control of two-spotted spider mites, European red mites, apple rust mite, peach silver mite, pear rust mite and pear psylla. Biological control of European red mites using Typhlodromus pyri was still possible whilst using Envidor.

Studies conducted in South Africa (SA Fruit Journal, 2002) on lemon and Valencia orange trees confirmed that citrus rust mite has developed resistance to applications of mancozeb, even at high rates, while spirodiclofen showed good efficacy, equal to the standard, Acarol (bromopropylate).

In Japan, citrus is the major fruit crop segment for mite-control products, followed by apple. Field trials in citrus with Daniemon 30SC in 2000-2001 resulted in excellent control at 56-92 DAT of Aculops pelekassi, equivalent to pyridaben. In 2001-2003, more trials with Daniemon 30SC were carried out on citrus for the control of mites. No systemic effects were found; there were long residual effects, and activities to eggs and infant mites were found to be higher. Good control of Tetranychus urticaeand Panonychus ulmiwas achieved in apples; the efficacy of spirodiclofen was unaffected by the METI resistance observed in the trials. Excellent control (99%; equivalent to fenpyroximate) was noted against A schlechtendali in apples with Ecomite 38WG in trials in 1998-2001. In cherry trees, spirodiclofen was highly effective against T urticae.

Spain, France and Italy are the principal target markets for acaricides in Europe, with citrus, grapes and apples being the target crops (around 70% of the EU acaricide market in 2002). Field trials with Envidor applied at the post-blossom stage (BBCH 69-73) in apple showed a slow initial effect followed by high levels of residual control of P ulmi,the rust mite Aculus schlechtendaliand the eryophid mite Epitrimerus piri. Applications made to apples in the pre-bloom period are also effective. In stone fruit, the product was shown to provide good control of P ulmiand T urticae.In Europe, grapes can be subject to phytophagous mite attack, mainly by P ulmi. Envidor applied at BBCH 75-85 gives long lasting control of P ulmi, Epitrimerus vitis and Eotetranychus carpini.

In Spanish citrus, Envidor was also very effective on P ulmiand T urticae. The effect was enhanced by use in mixture with Agridex mineral oil. Crop yield and quality were unaffected at double dose rates.

Trials on pome fruit in European orchards have shown that spirodiclofen can be used in IPM systems. These are important, not only in response to consumer preferences, but also to combat pest resistance. The product is selective to the main predator mites used in apples (Typhlodromus pyri) and in pears (Anthrocoris nemoralis). Any initial suppression of predators is soon recovered. Envidor can be used to support the predator:prey balance in the establishment of IPM and to correct outbursts of pests in stable systems. It was also shown to be safe to ladybird, lacewing and earwig beneficials.

CropUse

CropUses:
almonds, apples, cherries, citrus, coconut, coffee, grapevines, hops, nuts, ornamentals, papaya, pear tree, pome fruits, rubber, stone fruits, strawberries, tomatoes, vines

Product	Crop Rate
Envidor 2SC	Citrus 13 oz/acre (1 L/ha)
Envidor 2SC	Nuts* 14-18 oz/acre*
Envidor 2SC	Vines, pome fruit, stone fruit 16-18 oz/acre

Premix

Spirodiclofen+Fenbutatin oxide
Etoxazole+Spirodiclofen
Clofentezine+Spirodiclofen
Abamectin+Spirodiclofen

Type	AI concⁿ
Water-dispersable granule (WG)	38% (w/w) for Japan
Wettable powder (WP)	36% (w/w)
Suspension concentrate (SC)	3% (w/w) for Japan
Suspension concentrate (SC)	22% (w/w)
Suspension concentrate (SC)	24% (w/w)

Physical & Safety Data

Physical Properties

Molecular weight:411.3; Physical form:White powder. Vapour pressure:3 × 10-4 mPa (20 °C); Partition coefficient(n-octanol and water):logP = 5.8 ( pH 4, 20 °C); Solubility:In water 50 mg/l ( pH 4, 20 °C).;

Toxicology

Oral:Acute oral LD₅₀ for male and female rats >2500 mg/kg. Percutaneous:Acute percutaneous LD₅₀ for male and female rats >2000 mg/kg. Non-irritating to skin and eyes (rabbits). Not a skin sensitiser (SC formulation, guinea pigs). Inhalation:(4 h) for rats >5000 mg/m³.

Environmental Profile

Bobwhite quail _{[acute oral]}	LD₅₀ >2,000 mg ai / kg
Mallard duck _{[5 day feeding]}	LD₅₀ >5,000 mg ai / kg
Rainbow trout _{[96 h]}	LC₅₀ >0.0351 mg ai / L
Rainbow trout _{[97 d, ELS]}	NOEC = 0.00195 mg ai / L
Bluegill sunfish _{[96 h]}	LC₅₀ 0.0455 mg ai / L
Honeybee _{[oral & contact]}	LD₅₀ >300 μg/bee
Daphnia magna_{[48 h]}	EC₅₀ >0.508 mg ai / L
Daphnia magna_{[21 day, reproduction]}	NOEC 0.0248 mg ai / L
Earthworm	EC₅₀ >1,000 mg ai / kg (of dry soil)
Green algae _{[96 h, growth rate]}	EC₅₀ >0.06 mg ai / L

Fate in :
Spirodiclofen is non-toxic to ladybirds at 300 g/ha, and is slightly harmful to predatory mites under certain field conditions (BCPC 2000). Spirodiclofen is classified as non toxic to birds and mammals and of low acute toxicity to aquatic organisms. The increased toxicity to fish, daphnids and aquatic insects under laboratory conditions of chronic exposure is mitigated by the rapid degradation in water and recommended buffer zones. The product is non toxic to bees by oral or contact exposure and the risk to bee broods is avoided by recommendations not to spray during the blossom period.

Fate in soil:
Aerobic soil metabolism studies in 4 soils provided half-lives for spirodiclofen of 1.1 - 9.8 days. The major metabolites (each accounting for >10% of applied material) were the enol (by ester hydrolysis), a ketohydroxy product, a dihydroxy product and 2,4-dichlorobenzoic acid (DBC-acid); all are described in Pflanzenschutz-Nachrichten Bayer, 2002). The soil DT₅₀ was < 10 days for the enol metabolite and < 30 days for the other 3 metabolites. The DT₉₀ values for spirodiclofen ranged from 3.5 to 32.6 days.
Soil photolysis studies showed that photolysis does not play a significant role in the degradation of spirodiclofen; the DT₅₀ was 16 days in the light and 13 days in the dark.
Adsorption studies using an HPLC method gave a K_OC value of 31,037 for spirodiclofen, indicating strong soil binding and immobility. Batch equilibrium testing of the enol metabolite on 5 soils indicated high mobility (K_d = < 0.4 mL/g, K_OC = < 29 mL/g). The dihydroxy and DCB-acid metabolites were classified as intermediate and high mobility, respectively while the ketohydroxy metabolite was found to be of low mobility.
Leaching studies on 4 different soils in packed columns exposed to extreme irrigation showed spirodiclofen to be exclusively located in the top layer of soil with no parent being identified in the leachates. Aged leaching studies on a sandy loam soil with heavy rain irrigation again showed no parent in the leachates; the radioactivity in the leachate accounted for 53% of the applied dose and mainly comprised enol and DCB-acid metabolites.
Groundwater modelling using the Focus-Pearl simulator was based on data derived from the soil studies, annual single applications of spirodiclofen (96-144 g/ha) to pome fruit, stone fruit, citrus and grapes over a period of 20 years and worst case scenarios for soils and climatic conditions. The results indicated that groundwater concentrations at 1 metre for spirodiclofen and its major metabolites would not exceed 0.1 μg / L.

Fate in aquatic systems:
In aqueous hydrolysis studies, the half life of spirodiclofen is 64 days at pH4, 31 days at pH7 and 2 days at pH9. Enol is the major degradation product and did not break down further, even at elevated temperatures.
In aerobic water-sediment studies, the half life of spirodiclofen in the entire system was 4-5 days (silty sand and sandy loam soils); the parent material was rapidly (< 1 day) eliminated from the water phase by degradation and partitioning to the sediment. The main metabolite was the enol.
In anaerobic water-sediment studies, the half life of spirodiclofen in the entire system was 12 days (loamy sand soil); the parent material was rapidly (< 1 day) eliminated from the water phase by partitioning to the sediment where it was quickly metabolised. The main metabolite was the enol.
Photodegradation was slow in aqueous systems (DT₅₀ around 115 days in buffer at pH4 and 71 days in pond water). The degradation of spirodiclofen was attributed largely to hydrolytic processes as the half lifes were similar in the dark controls, but the minor enol metabolite was rapidly degraded by photolytic processes.

Transport Information

Hazard Class:O (Obsolete as pesticide, not classified)