5,7-dichloro-4-(4-fluorophenoxy)quinoline;quinoxyfen (ISO)

Toxicity to terrestrial arthropods

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to terrestrial arthropods: short-term

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EPA OPP 141-1 (Honey Bee Acute Contact Toxicity)

Deviations:

yes

Remarks:

Refer any other information on material and methods section. The deviations observed did not adversely affect the results of the study.

GLP compliance:

yes

Application method:

contact

Specific details on test material used for the study:

- Substance ID: TSN 100010
- Name of substance: XDE-795
- Purity: 99%

Analytical monitoring:

no

Vehicle:

yes

Remarks:

acetone

Test organisms (species):

Apis mellifera

Animal group:

Hymenoptera (honeybees)

Study type:

laboratory study

Limit test:

no

Total exposure duration:

46 h

Test temperature:

19.8 to 23.1°C

Humidity:

65 ± 16%

Photoperiod and lighting:

Photoperiod: Approximately 8 hours light and 16 hours dark
Lighting: Fluorescent tubes that emitted wavelengths similar to natural sunlight

Nominal and measured concentrations:

Negative control, solvent control, 1.6, 3.1, 6.3, 12.5, 25 µg a.i./bee

Reference substance (positive control):

no

Key result

Duration:

46 h

Dose descriptor:

LD50

Effect conc.:

> 25 other: µg/bee

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mortality

Remarks on result:

other: highest dose tested

Duration:

46 h

Dose descriptor:

other: NOED

Effect conc.:

25 other: µg/bee

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mortality

Remarks on result:

other: highest dose tested

Validity criteria fulfilled:

yes

Conclusions:

46 hour contact LD50 (honey bee): >25 µg/bee (highest dose tested)
46 hour contact NOED (honey bee): 25 µg/bee

Executive summary:

The test substance was tested for acute contact toxicity with the honey bee following EPA guideline 141-1. Five treatment levels representing 1.6, 3.1, 6.3, 12.5 and 25 µg a.i./bee were tested along with a solvent and a negative control for 2 days. Two replicates were tested at each dose with 50 bees per replicate.

At test termination, mortality in the negative and solvent control groups was 5% and 8%, respectively. Small numbers of immobile or lethargic bees were noted during the test in both control groups. Bees in the 1.6, 3.1, 6.3, 12.5, and 25 µg a.i./bee doses had mortalities of 7, 6, 6, 10, and 7%, respectively, by test termination. Small numbers of immobile or lethargic bees were observed in all treatment levels during the test. The numbers of bees exhibiting mortality and clinical signs were small, not dose responsive, and not considered to be treatment related.

The acute contact LD50 value for honey bees exposed to the test substance was determined to be greater than 25 µg a.i./bee, the highest dose tested. The no observed effect dose was determined to be 25 µg a.i./bee. The test substance was classified as relatively nontoxic to honey bees according to the toxicity categories of Atkins.

Reference 2

Endpoint:

toxicity to terrestrial arthropods: short-term

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EPA OPP 141-1 (Honey Bee Acute Contact Toxicity)

Deviations:

yes

Remarks:

The relative humidity was above approximately 40%. This did not adversely affect the results of the study.

GLP compliance:

yes

Application method:

contact

Specific details on test material used for the study:

- Substance ID: TSN 100010
- Name of substance: XDE-795
- Purity: 99%

Analytical monitoring:

no

Vehicle:

yes

Remarks:

acetone

Test organisms (species):

Apis mellifera

Animal group:

Hymenoptera (honeybees)

Study type:

laboratory study

Limit test:

no

Total exposure duration:

48 h

Test temperature:

33.1 to 33.7°C

Humidity:

37 to 53%

Photoperiod and lighting:

The bees were maintained under continuous darkness, except during periods of dosing and observations

Nominal and measured concentrations:

Negative control, solvent control, 6.3, 12.5, 25.0, 50.0, and 100 µg a.i./bee

Reference substance (positive control):

no

Key result

Duration:

48 h

Dose descriptor:

LD50

Effect conc.:

> 100 other: µg/bee

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mortality

Remarks on result:

other: highest dose tested

Duration:

48 h

Dose descriptor:

other: NOED

Effect conc.:

100 other: µg/bee

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mortality

Remarks on result:

other: highest dose tested

Validity criteria fulfilled:

yes

Conclusions:

48 hour contact LD50 (honey bee): >100 µg/bee (highest dose tested)
48 hour contact NOED (honey bee): 100 µg/bee

Executive summary:

The test substance was tested for acute contact toxicity with the honey bee following EPA guideline 141-1. Five treatment levels representing 6.3, 12.5, 25.0, 50.0 and 100 µg a.i./bee were tested along with a solvent and a negative control for 2 days. Four replicates were tested at each dose with 25 bees per replicate.

At the 6.3, 12.5, 25.0, 50.0 and 100 µg a.i./bee test concentrations, the percent mortality was 0% (0 of 100), 0% (0 of 100), 1% (1 of 100), 2% (2 of 100) and 1% (1 of 100), respectively. At the termination of the test, one lethargic bee was noted in one replicate of the 50.0 µg a.i./bee treatment group and one immobile bee was noted on one replicate of the 100 µg a.i./bee treatment group. All other surviving bees in the treatment groups were normal in appearance and behavior throughout the test period. The percent mortality noted in the treatment groups was comparable to the percent mortality noted in the control groups and was not dose responsive. Therefore, the mortalities were not considered treatment related.

The 48-hour contact LD50 value for honey bees exposed to the test substance was determined to be greater than 100 µg a.i./bee, the highest dose tested. The no observed effect dose was determined to be 100 µg a.i./bee. The test substance was classified as relatively nontoxic to honey bees according to the toxicity categories of Atkins.

Reference 3

Endpoint:

toxicity to terrestrial arthropods: short-term

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EPA OPP 141-1 (Honey Bee Acute Contact Toxicity)

Deviations:

yes

Remarks:

The relative humidiy was above approximately 41%. This did not adversely affect the results of the study.

GLP compliance:

yes

Application method:

oral

Specific details on test material used for the study:

- Substance ID: TSN 100010
- Name of substance: XDE-795
- Purity: 98.7%

Analytical monitoring:

no

Vehicle:

yes

Remarks:

diet

Test organisms (species):

Apis mellifera

Animal group:

Hymenoptera (honeybees)

Study type:

laboratory study

Limit test:

no

Total exposure duration:

48 h

Test temperature:

34.2 to 34.6°C

Humidity:

46 to 50%

Photoperiod and lighting:

The bees were maintained under continuous darkness except during periods of diet presentation and observations

Nominal and measured concentrations:

Negative control, 62.5, 125, 250, 500, 1000 ppm a.i.

Reference substance (positive control):

no

Key result

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

> 1 000 ppm

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mortality

Remarks on result:

other: highest concentration tested

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

1 000 ppm

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

other: mortality and clinical observations

Remarks on result:

other: highest concentration tested

Validity criteria fulfilled:

yes

Conclusions:

48-hr LC50 (honey bee): >1000 ppm (highest concentration tested)
48-hr NOEC (honey bee): 1000 ppm (highest concentration tested)

Executive summary:

The test substance was tested in a dietary toxicity with the honey bee following EPA guideline 141-1. Five treatment levels representing 62.5, 125, 250, 500, and 1000 ppm by measuring a calculated amount of the test substance and mixing it thoroughly with a sufficient amount of honey. All test diet concentrations were adjusted for the reported purity of the active ingredient in the test substance. A negative control group was maintained concurrently. Four replicate test chambers were maintained in each treatment and control group, with 25 bees in each test chamber. Observations of mortality and other clinical signs were made approximately 1/2, 1-1/4, 24 and 48 hours after test initiation. Cumulative mortality percentages observed in the treatment groups were used to determine the LC50 value at 48 hours. The no observed effect concentration was determined by examination of the mortality and clinical observation data.

The mortalities and effects observed at the 62.5 through 1000 ppm a.i. test concentrations were variable between replicates and were not dose responsive. Therefore, the mortalities and effects at these concentrations were not considered treatment related. The 48-hour dietary LC50 value for honey bees exposed to the test substance was determined to be greater than 1000 ppm a.i., the highest concentration tested. The 48-hour no observed effect concentration was 1000 ppm a.i..

Reference 4

Endpoint:

toxicity to terrestrial arthropods: short-term

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 213 (Honeybees, Acute Oral Toxicity Test)

Deviations:

no

GLP compliance:

yes

Application method:

oral

Specific details on test material used for the study:

- Substance ID: TSN 100097
- Name of substance: Technical-grade quinoxyfen
- Lot number: DECO-97-152-1
- Purity: 97.3%

Analytical monitoring:

no

Vehicle:

yes

Remarks:

50% w/v solution of sucrose in purified water

Test organisms (species):

Apis mellifera

Animal group:

Hymenoptera (honeybees)

Study type:

laboratory study

Limit test:

no

Total exposure duration:

48 h

Test temperature:

Range finding test: 24.9-26.0ºC
Definitive test: 24.8-25.9ºC

Humidity:

Range finding test: 53-59%
Definitive test: 55-63%

Photoperiod and lighting:

The cages were maintained in darkness except during assessments

Nominal and measured concentrations:

Range finding test: 1, 10, 50, 100 µg a.i./bee
Definitive test: Nominal: 50, 100 µg a.i./bee; Mean dose taken: 51.1, 100.1 µg a.i./bee

Reference substance (positive control):

yes

Remarks:

dimethoate

Duration:

24 h

Dose descriptor:

LD50

Effect conc.:

> 100 other: µg/bee

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mortality

Remarks on result:

other: highest dose tested

Key result

Duration:

48 h

Dose descriptor:

LD50

Effect conc.:

> 100 other: µg/bee

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mortality

Remarks on result:

other: highest dose tested

Duration:

48 h

Dose descriptor:

other: NOER

Effect conc.:

100 other: µg/bee

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mortality

Remarks on result:

other: highest dose tested

Validity criteria fulfilled:

yes

Conclusions:

24- and 48-hr LD50 (honeybee): >100 µg/bee (highest dose tested)
48-hr NOER: 100 µg/bee

Executive summary:

The aim of this study was to determine the oral median lethal dose (LD50) of the test substance to the honeybee, Apis mellifera, following OECD guideline 213.

Worker bees were exposed to treatment solutions (nominally 20 µL/bee) via feeding vials placed in each cage. These contained the diluted products mixed into a 50% w/v solution of sugar in purified water. Untreated 50% w/v sugar solution was provided for the control group. Upon consumption of the dose, or at 6 hours after first exposure, the treated feeding vials were replaced with ones containing untreated sugar solution. The mean amount of test item solution consumed per bee was determined by weighing the feeding vials before and after being placed in the cages. Untreated 50% w/v sugar solution was then provided as sustenance for the bees for the remainder of the test. Bee mortality assessments were made up to 48 h.

Following an initial range-finding test, the test substance was evaluated in a definitive test at two application rates, nominally equivalent to 100 and 50 μg/bee. However, by weighing the total amount of food consumed, it was calculated that the mean doses actually consumed were 100.1 and 51.1 μg/bee, respectively. Five replicate cages of 10 bees each (i.e. 50 bees in total) were used for each test substance treatment rate and the control treatment.

To confirm the sensitivity of the test insects, bees from the same hive were also tested with technical-grade dimethoate (dissolved in acetone and diluted with 50% w/v sugar solution) in a separate bioassay. The dimethoate was applied at a series of doses (nominally 0.20, 0.175, 0.15, 0.125 and 0.10 µg a.i./bee). Three replicate cages of 10 bees each (i.e. 30 bees per treatment in total) were used for each treatment and acetone diluted in 50% w/v sugar solution (five replicate cages) was used as a control.

At 48 h, mortality in the control treatment was 2%. This compared with 4% and 0% mortality (2% and 0% corrected mortality, respectively) for the nominal 100 and 50 µg/bee treatment rates, respectively. It was therefore concluded that the oral LD50 for the test substance at both 24 h and 48 h was higher than 100 µg/bee. As no statistically significant effects were observed in these and the mortality assessments, it was concluded that the 48-h NOER for test substance was 100 μg/bee and no value could be derived for the LOER.

The 24 h-LD50 value derived for oral exposure to technical-grade dimethoate was 0.152 μg a.i./bee (95% confidence limits of 0.131 and 0.166 μg a.i./bee). This indicated that the test insects were of an acceptable sensitivity.

Description of key information

24- and 48-hour Oral LD₅₀ (honeybee): >100 µg/bee (highest dose tested); OECD 213; Reliability = 1

46-hour contact LD₅₀ (honey bee): >25 µg/bee (highest dose tested); EPA OPP 141-1; Reliability = 1

48-hour contact LD₅₀ (honey bee): >100 µg/bee (highest dose tested); EPA OPP 141-1; Reliability = 1

48-hour dietary LC₅₀ (honey bee): >1000 ppm (highest concentration tested); EPA OPP 141-1; Reliability = 1