clothianidin (ISO); (E)-1-(2-chloro-1,3-thiazol-5-ylmethyl)-3-methyl-2-nitroguanidine

Toxicity to terrestrial arthropods

Link to relevant study record(s)

Reference

Endpoint:

toxicity to terrestrial arthropods: long-term

Type of information:

experimental study

Adequacy of study:

key study

Study period:

14 Aug - 11 Sep, 2000

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

ISO 11267 (Inhibition of Reproduction of Collembola by Soil Pollutants)

Version / remarks:

1998

Deviations:

no

Remarks:

stated in the report. According to OECD current guideline 232: 5 replicates in control instead of 8, peat content of 10% instead of 5%.

GLP compliance:

yes (incl. QA statement)

Remarks:

Niedersächsisches Umweltministerium, delivered on 07 Jul, 1997

Application method:

mixed into soil

Analytical monitoring:

no

Vehicle:

no

Details on preparation and application of test substrate:

The dosages in mg product/kg dry weight were applied once at test begin for all replicates of one treatment into the test medium. The test item was dissolved in 25 mL demineralised water, additionally 9.6 mL demineralised water were given to the test medium to adjust a humidity of 40 - 60% of the maximal water capacity. The test substrate was mixed with a long handled blender for at least three minutes to insure a homogeneous distribution of the test item. Afterwards soil amounts (30 g wet weight per replicate) were distributed to the single replicates. To insure easy immigration of springtails the substrate in the test containers was not compressed.

Test organisms (species):

Folsomia candida

Animal group:

Collembola (soil-dwelling springtail)

Details on test organisms:

Folsomia candida was bred at the test facility in covered polyethylene flasks (height 7.5 cm, diameter 7 cm) on artificial soil containing 90% w/w calcium sulphate dihydrate and 10% w/w powdered activated charcoal.
Juvenile springtails (10-12 days old) were used.
The springtails were fed with granulated dry yeast of commercially available quality.

Study type:

laboratory study

Limit test:

no

Total exposure duration:

28 d

Test temperature:

18.5 - 21.5°C

pH (if soil or dung study):

5.90 - 6.36

Humidity:

40-60% of the WHC

Photoperiod and lighting:

16 h light / 8 h dark about 587.3 lux

Details on test conditions:

Artificial soil as test medium consists of components as follows:
-10 % peat, air dried and finely ground
- 20 % kaolin (kaolinite content > 30 %)
- 69 % quartz sand (sand with > 50 % particles sized 50-200 µm)
- 0.4 % calcium carbonate (CaCO3)
Glass beakers with a volume of 100 mL were used and covered with PARAFILM.
5 replicates per dosage of test and reference item and control were used with 10 juvenile springtails per replicate

Nominal and measured concentrations:

Nominal: 0.01, 0.032, 0.1, 0.32 and 1.0 mg product/kg soil dry weight

Reference substance (positive control):

yes

Remarks:

E 605 FORTE (Parathion / 520 g/L)

Key result

Duration:

28 d

Dose descriptor:

EC50

Effect conc.:

0.76 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

reproduction

Key result

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

0.32 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

reproduction

Details on results:

The mean number of juveniles found in the untreated control was 697. The mean number of juveniles of the test item treatments 0.01 mg product/kg was 705, at 0.032 mg product/kg 601, at 0.1 mg product/kg 751, at 0.32 mg product/kg 606, and at 1.0 mg product/kg 252.
When compared to control group only the concentration 1.0 mg product/kg was statistically significantly different from the control (ANOVA, DUNNETT'S METHOD, p < 0.05).

Results with reference substance (positive control):

E605 FORTE was tested as toxic reference treatment in a separate study (LC50 = 0.14 mg product/kg for corrected adult mortality and EC50 = 0.13 mg product/kg for reproduction).

Please refer to "overall remark/ attached background material" field for result tables.

Validity criteria:

- The number of juveniles in the control should be > 100 per replicate. In this study the number of juveniles in the control group was at least 582 juveniles per replicate.
- The coefficient of variation of the reproduction rate should be < 30 % in control group. In this study the coefficient of variation was 14.6 % for control group.
- The mortality in the control group should be < 20 %. In this study the adult control mortality was 2 % in control group.
Since the the quality criteria were fulfilled the study is assumed to be valid .

Validity criteria fulfilled:

yes

Remarks:

accordong to the report. For further details please refer to “Any other information on results incl. tables”.

Conclusions:

The present guideline study was conducted in compliance with GLP. Under the test conditions used, for Folsomia candida reproduction, the EC50 28-day was 0.76 mg a.s./kg dws and the NOEC 28-day was 0.32 mg a.s./kg dws.

Description of key information

From key study, the 28 -day EC50 and NOEC for terrestrial arthropods exposed to the present test material were 0.76 and 0.32 mg a.s./kg dry weight soil.

Key value for chemical safety assessment

Short-term EC50 or LC50 for soil dwelling arthropods:

0.76 mg/kg soil dw

Long-term EC10, LC10 or NOEC for soil dwelling arthropods:

0.32 mg/kg soil dw

Additional information

There are eight GLP-studies available for toxicity testing to terrestrial arthropods and one of them was identified as a key study.

 

In the key study (2000), the chronic toxicity of test substance to collembola (Folsomia Candida) was investigated after 28-day exposure according to ISO/FDIS 11267 (1998) guidelines. The test item was incorporated into the soil. Ten female collembolan per replicate were exposed to concentrations of 0.01, 0.032, 0.1, 0.32 and 1.0 mg/kg soil dry weight, alongside with a control. The reproduction EC₅₀ and NOEC were determined to be 0.76 and 0.32 mg a.s./kg soil d.w., respectively.

 

Additionally, four studies on Apis mellifera, two studies on Hypoaspis aculeifer and one study on Aphidius rhopalosphi were conducted with the substance or the formulated product. The acute LD₅₀ for adult honey bees was 0.04426 µg a.s./bee for oral and 0.00379 µg a.s./bee contact exposure. The chronic LDD₅₀ for adult honey bees was 0.00183 µg a.s./bee/day. The NOEC for larvae exposed to repetitive exposure (3 or 6 days) ranged from 40 to 680 µg a.s./kg diet. For H. aculeifer; the LC₅₀ was > 100 mg a.s./kg dry weight soil and the NOEC reproduction was 148.5 mg a.s./kg dry weight soil. The LR₅₀ forA. rhopalosiphi was 0.001448 mg/kg dry weight soil.