cis-4-[3-(p-tert-butylphenyl)-2-methylpropyl]-2,6-dimethylmorpholine

Toxicity to terrestrial arthropods

Link to relevant study record(s)

Reference

Endpoint:

toxicity to terrestrial arthropods: short-term

Type of information:

experimental study

Adequacy of study:

key study

Study period:

28.07.- 05.08.1999

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Qualifier:

according to guideline

Guideline:

other: EPPO 170, Side-effects on honeybees

Version / remarks:

1992

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Test organisms (species):

Apis mellifera

Animal group:

Hymenoptera (honeybees)

Details on test organisms:

TEST ORGANISM
- Common name: Honeybee
- Source: colonies from a breeding line of a commercial beekeeper in Baden-Württemberg, Germany

- Age at test initiation: approx. 22 - 32 days

- Cultural background (if honeybees): Apis mellifera carnica (Hymenoptera, Apidae)
- Disease free: yes, healthy colony

Study type:

laboratory study

Limit test:

no

Total exposure duration:

48 h

Test temperature:

24°C - 29°C

Humidity:

relative humidity 50% - 75 %

Photoperiod and lighting:

24 h darkness

Details on test conditions:

TEST SYSTEM
- Test container / cage (material, size): cages made of high grade steel (10 x 5.5 x 8.5 cm); frontside: transparent pane for observation; perforated board on the bottom (guaranteering sufficient air supply for the test insects
- Details of emergence and fecundity chambers:
- No. of organisms per container (treatment): 10 bees
- No. of replicates per treatment group: 5

EFFECT PARAMETERS MEASURED (with observation intervals if applicable):
LD50, (50% mortality of honeybees after exposure over 24 h or 48 h)

FOOD CONSUMPTION (if oral study)
- Starving before Test feeding: 2 hours 25 minutes
- Amount of treated diet consumed per group: offered amount of 250 µL per cage

Nominal and measured concentrations:

nominal concentrations: Control, 6.25, 12.5, 25.0, 50.0, 100.0 µg a.s./bee; analysed: 95.7% (w/w)

Reference substance (positive control):

yes

Remarks:

Dimethoate (BAS 152 11; 400 g/L)

Key result

Duration:

48 h

Dose descriptor:

LD50

Effect conc.:

> 95.6 µg per animal

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: Oral test

Key result

Duration:

48 h

Dose descriptor:

LD50

Effect conc.:

> 100 µg per animal

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: Contact test

Details on results:

In the oral toxicity test the maximum nominal test level of Fenpropimorph (100 µg a.s./bee) corresponded to an actual intake of 95.6 µg a.s./bee. Up to this concentration the corrected mortality did not exceed 21.7%.
In the contact toxicity test the corrected mortality did not exceed 2.0% at Fenpropimorph concentrations between 6.25 and 100 µg a.s./bee.
The LD50 of the test substance was determined to be > 95.6 µg a.s./bee in the oral test (48 h) and > 100 µg a.s./bee in the contact test (48 h).

Results with reference substance (positive control):

The LD50 oral and LD50 contact of the active ingredient dimethoate was determined occasionally during the bee testing season in order to examine the variability of the bees used for the test.

Table 8.3/1       Toxicity of Fenpropimorph to honeybees (Apis mellifera carnica L.) in oral and contact toxicity
	Oral test	Contact test
Mortality	mortality did not exceed 21.7% at 95.6 µg a.s./bee	mortality did not exceed 2.0% at 100 µg a.s./bee
Endpoints [µg a.s./bee]
LD50	> 95.6	> 100

 

The reference substance showed a corrected mortality of 97.8% in the oral test (48 h) and of 56% in the contact test (48 h).

Conclusions:

Toxicity of Fenpropimorph was tested in both an acute oral and a contact test on honeybees. The LD50 (48 h) was >100 µg a.s./bee in the contact toxicity test and >95.6 µg a.s./bee in the oral toxicity test.

Description of key information

After 48 h, the oral toxicity test with Apis mellifera revealed an LD50 >95.6 µg/bee, the acute contact toxicity study  an LD50 >100 µg/bee.

Additional information

Key study (BASF, 1999/11450, 1999)

An acute contact toxicity study with fenpropimorph in honeybees (Apis mellifera) was conducted according to guideline EPPO 170 (1992). Toxicity of fenpropimorph was tested in both an acute oral and a contact test on honeybees. The honeybees were exposed to the following five test substance concentrations: 6.25, 12.5, 25.0, 50.0 and 100.00 µg/bee. The organisms were observed at 2, 4, 24 and 48 hours after application to determine their death rate. The LD₅₀ (48 h) was >100 µg a.s./bee in the contact toxicity test and >95.6 µg a.s./bee in the oral toxicity test.

 

Additionally it shall be mentioned that in the publication ''Effects of pesticides on the reproduction of Hypoaspis aculeifer (Gamasida: Laelapidae) in the laboratory'' from the year 1995 from Paul H. Krogh the effects of fenpropimorph on the predacious mite H. aculeifer were investigated. During a test duration of 3 weeks a NOEC > 6.0 mg/kg was determined via a single species reproductive test system (no test guideline is available).