1,2-dichlorobenzene

Toxicity to terrestrial arthropods

Administrative data

Endpoint:

toxicity to terrestrial arthropods, other

Remarks:

Several studies on the toxicity of 1,2-dichlorobenzene to terrestrial arthropods were summarized in the assessment of the BUA report 53 (1990).

Type of information:

other: BUA report

Adequacy of study:

other information

Reliability:

other: BUA report

Rationale for reliability incl. deficiencies:

other: BUA report

Data source

Reference

Reference 1

Reference Type:

other: BUA report

Title:

Unnamed

Year:

1990

Reference 2

Reference Type:

publication

Title:

Chemicals affecting the preimaginal stages of the housefly. V. Vapour toxicity of the dichlorobenzenes to housefly pupae.

Author:

Levinson ZH

Year:

1955

Bibliographic source:

Riv parassitol, 16: 253-256

Reference 3

Reference Type:

publication

Title:

The fever fly, Dilophus febrilis L., and methods for control of its larvae in cultivated lawns

Author:

Edwards EE

Year:

1941

Bibliographic source:

Ann Appl Biol, 28: 34-38

Reference 4

Reference Type:

publication

Title:

Control of fly larvae in simulated pit latrines and in carcasses

Author:

McDuffie WC, Lindquist AW, Madden AH

Year:

1946

Bibliographic source:

J Econ Entomol, 39: 743-749

Reference 5

Reference Type:

publication

Title:

The use of fatty acids in insecticidal aerosols

Author:

Sullivan WN, Goodhue LD, Fales JH

Year:

1941

Bibliographic source:

Science, 94: 444-445

Reference 6

Reference Type:

publication

Title:

Insecticidal smokes... Their application in the control of household insects.

Author:

Goodhue LD, Sullivan WN

Year:

1941

Bibliographic source:

Soap and Sanit Chemicals, 17: 98-100

Reference 7

Reference Type:

publication

Title:

Fumigating action of a mixture of orthodichlorobenzene and naphthalene applied by a new method

Author:

Sullivan WN, McGovran ER, Goddhue LD

Year:

1941

Bibliographic source:

J Econ Entomol, 34: 79-80

Reference 8

Reference Type:

publication

Title:

Effects of fumigants on the water loss in Periplaneta americana (L.)

Author:

Bhatia SS

Year:

1976

Bibliographic source:

Proc Indian Acad Sci, 83B: 18-25

Reference 9

Reference Type:

publication

Title:

Studies on the control of fly larvea by chemicals. I. Comparative effects of various insecticides in the laboratory bioassay method for contact poisons.

Author:

Toyama T, Suzuki T

Year:

1954

Bibliographic source:

Botyu Kagaku 19: 115-121

Reference 10

Reference Type:

publication

Title:

Prevention of extraneous substances (specially mite) in medicines. (6) Effect of various chemicals for mites.

Author:

Honma S

Year:

1967

Bibliographic source:

Yakuzaigaku 27: 192-196

Materials and methods

Principles of method if other than guideline:

BUA report

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

1,2-dichlorobenzene

EC Number:

202-425-9

EC Name:

1,2-dichlorobenzene

Cas Number:

95-50-1

Molecular formula:

C6H4Cl2

IUPAC Name:

1,2-dichlorobenzene

Results and discussion

Any other information on results incl. tables

BUA report:

Several studies on the toxicity of 1,2-dichlorobenzene to terrestrial arthropods were summarized in the assessment of the BUA report 53 (1990). However, these publications were not reliable as the studies were not conducted following todays test methods.

Exposure of housefly pupae (Musca vicina) for three hours to an atmosphere saturated with o-dichlorobenzene at 30 +/- 1 °C yielded a hatching rate of 2 +/- 2% whereas the corresponding figure for the control was 94 +/- 2%.

When soil was treated with a 1% emulsion of o-dichlorobenzene at a rate of 54.4 g/m2 with a vew to controlling the larvae of the fever fly (Dilophus febrilis L.; now called: Philia febrilis), the mean mortality rate was 72%.

Studies on housefly larvae (Musca domestica) whose eggs and larvae were applied to a semi-solid, simulated-excrement nutrient showed that 7 mg/cm2 of o-dichlorobenzene was ovicidal and 35 mg/cm2 was larvicidal within 2 -4 days.

Exposure of houseflies (Musca domestica) for 30 minutes to o-dichloronenzene applied in aerosol form in a concentration of 12.85 g/m3 yielded a mortality rate after two days of 2%. The toxicity was greatly enhanced by addition of fatty acids, e.g., oleic or lauric acid, which themselves are ineffective when used alone. Thus, the mortality rates in the presence of these acids in a concentration of 2.5 g/m3 were 55% and 60% respectively.

A mortality rate of 100% occurred when American and German cockroaches and bedbugs were exposed to a mixture of o-dichlorobenzene and lauric acid in a concentration of 21 -24 g/m3 and 1.1 -1.2 g/m3.

When houseflies (Musca domestica) and American cockroaches (Periplaneta americana) were exposed for 24 hours to a mixture of 12.7 g/m3 of o-dichlorobenzene and 4 g/m3 of naphthalene, the mortality rates were 100% for the flies, 53.6% for the cockroach noymphs and 94.4% for the adult cockroaches. Ten days later, the mortality rate for the nymphs and the adult cockroaches was also 100%.

4577 mg/m3 of o-dichlorobenzene proved fatal to cockroaches (Periplaneta americana); no information is provided on length of exposure. While the cratures were still alive, the thoracic spiracles remained open longer, whereby loss of water occurred at approximately three times the usual rate.

Larvae of blowflies (Cochliomyia macellaria) in animal carcasses are instantaneously immobilized and killed by 34 -54 grammes of o-dichlorobenzene sprayes per kilogramme of carcass. From 6.8 -10.8 grammes of o-dichlorobenzene sprayed per kilogramme of carcass in a 20 -% solution in fuel oil, which is ineffective on its own, had the same larvicidal action.

A study of the larvicidal action on the meatfly larva, Sarcophaga peregrina ROBINEAU-DESVOIDY, yielded LC50 and LC99 values of ca. 1.4 g/L and ca. 2.8 g/L respectively for 24 hours contact with o-dichlorobenzene emulsions and a 24 -hour follow-up period.

In vitro tests of toxicity to mites (Tyrophagus dimidiatus) revealed that exposure for 1 minute and 4 minutes to o-dichlorobenzene in a concentration of 10 g/L (the solution contained water and 4% (w/w) of Tween 20) resulted in the deaths of 50% and 100% respectively of the specimens.

The toxic effect of o-dichlorobenzene on aphids of the species Aphis rumicis L. were also investigated. Spraying of an emulsion preparation containing 10 g/L of o-dichlorobenzene induced death in 10% of the specimens (adult, apterous, agamic females). o-Dichlorobenzene proved 100% fatal in concentrations of at least 40 g/L.

In studies o fthe toxicity to eggs of the geometrid moth, Selenia tetralunaria HUFN, emulsified o-dichlorobenzene sprayed in concentrations of at most 50 g/L did not prove toxic.

The effects on the termites, Postelectrotermes militaris (DESNEUX; = Neotermes militaris DESNEUX), that infest the roots and trunk of the tea plant was investigated in a field trial. The galleries in the wood of the infested tea plant were gassed with 10 mL o-dichlorobenzene per plant (the gallery system is accessed by cutting the branch) and the openings were sealed with clay or putty. One week after treatment, the mortality rate was found to be 10.6%.

Combating of termites by treating the soil with o-dichlorobenzene proved not to be very successful in the practicable concentrations and applied amounts. Thus, treatment with as much as 17.5 kg/m3 of soil yielded erratic results. However, effective control was obtained with 123 kg/m3.

Exposure for 16.7 h at 15°C of wireworm larvae of the genus Agriotes to 10.2 g/m3 of o-dichlorobenzene present in vapour form in damp air proved lethal. Larvae exposed to 7 g/m3 of o-dichlorobenzene for the same length of time recovered on cessation of exposure.

The brood of the Douglas-fir beetle (Dendroctonus pseudotsugae HOPKINS) was effectively controlled in standing trees or logs by spraying them with o-dichlorobenzene in diesel oil in a volume ratio of 1:3 or 1:5. Application of approximately 30 or 40 mg of o-dichlorobenzene per cm2 of bark yielded a mortality rate of 100%. The reason for this high application rate in Douglas firs is the ability of the bark of these trees to absorb 2 -3 times more of the oily preparations relabive to the bark of other conifers.

With a view to controlling the Engelmann spruce beetle (Dendroctonus engelmanni HOPKINS), standing trees and logs were treated similarly with a solution of 200 g/L of o-dichlorobenzene in fuel oil. Mortality rates of 95 -98% were recorded.

In an oil-in-water emulsion containing 20% (v/v) fuel oil, o-dichlorobenzene, present in a concentration of 20 g/L emulsion, proved lethal to the larvae and pupae of the mountain pine beetle, Dendroctonus monticolae HOPKINS whereas 77% of the young adults survived. The brood survival rate was 63% when a concentration of 30 g/L of emulsion (containing 33% (v/v) fuel oil) was used.

When the trunk of the locust tree (Robinia pseudoacacia L.) was sprayed with emulsions containing at least 8% o-dichlorobenzene, a 100% mortality rate was recorded fo the larvae of the locust borer, Cyllene robiniae FORST. In contrast, an 8% o-dichlorobenzene emulsion was not fatal to the larvae of the codling moth, Carpocapsa pomonella.

After injecting o-dichlorobenzene into grapevine stems infested with larvae of the wasp beetle, Chlorophorus varius MULL, a 75% mortality rate among those larvae immediatley beneath the bark was determined.

Sprayed o-dichlorobenzene acts as a direct-contact insecticide for skins and hides infested with the hide beetle, Dermestes vulpius FAB., and its larvae as well as for the webbing clothes moth of the species Tineola biselliella HUM., proving fatal within 10 -15 minutes.

Twenty four hours exposure to 40 g/m3 of o-dichlorobenzene in vapour form did not have any lethal effect on the flour weevil, Tribolium confusum FAB., the Indian meal moth, Plodia interpunctella HBN., the rice weevil, Sitophilus oryza L., and the granary weevil, Sitophilus granarius L.

For Calandra oryzae L., LC50 and LC95 values of 17 -19 g/m3 and 30 -33 g/m3 were determined. The corresponding values for Calandra sasakii TAKAHASHI were reported to be 6 -8 g/m3 and 12 -18 g/m3. The lower values in each case pertain to weevils that had a higher fat content owing to their having been nourished on a diet richer in fat. It was concluded from this finding that o-dichlorobenzene is absorbed into the insect's body fat and is thus eliminated more slowly.

Five hours exposure of rice weevils, Calandra oryzae L., to concentrations of o-dichlorobenzene greater than 5 g/m3 led to paralysis and death.

Applicant's summary and conclusion

Executive summary:

Several studies on the toxicity of 1,2-dichlorobenzene to terrestrial arthropods were summarized in the assessment of the BUA report 53 (1990). However, these publications were not reliable as the studies were not conducted following todays test methods.

Exposure of housefly pupae (Musca vicina) for three hours to an atmosphere saturated with o-dichlorobenzene at 30 +/- 1 °C yielded a hatching rate of 2 +/- 2% whereas the corresponding figure for the control was 94 +/- 2%.

When soil was treated with a 1% emulsion of o-dichlorobenzene at a rate of 54.4 g/m2 with a vew to controlling the larvae of the fever fly (Dilophus febrilisL.; now called:Philia febrilis), the mean mortality rate was 72%.

Studies on housefly larvae (Musca domestica) whose eggs and larvae were applied to a semi-solid, simulated-excrement nutrient showed that 7 mg/cm2 of o-dichlorobenzene was ovicidal and 35 mg/cm2 was larvicidal within 2 -4 days.

Exposure of houseflies (Musca domestica) for 30 minutes to o-dichloronenzene applied in aerosol form in a concentration of 12.85 g/m3 yielded a mortality rate after two days of 2%. The toxicity was greatly enhanced by addition of fatty acids, e.g., oleic or lauric acid, which themselves are ineffective when used alone. Thus, the mortality rates in the presence of these acids in a concentration of 2.5 g/m3 were 55% and 60% respectively.

A mortality rate of 100% occurred when American and German cockroaches and bedbugs were exposed to a mixture of o-dichlorobenzene and lauric acid in a concentration of 21 -24 g/m3 and 1.1 -1.2 g/m3.

When houseflies (Musca domestica) and American cockroaches (Periplaneta americana) were exposed for 24 hours to a mixture of 12.7 g/m3 of o-dichlorobenzene and 4 g/m3 of naphthalene, the mortality rates were 100% for the flies, 53.6% for the cockroach noymphs and 94.4% for the adult cockroaches. Ten days later, the mortality rate for the nymphs and the adult cockroaches was also 100%.

4577 mg/m3 of o-dichlorobenzene proved fatal to cockroaches (Periplaneta americana); no information is provided on length of exposure. While the cratures were still alive, the thoracic spiracles remained open longer, whereby loss of water occurred at approximately three times the usual rate.

Larvae of blowflies (Cochliomyia macellaria) in animal carcasses are instantaneously immobilized and killed by 34 -54 grammes of o-dichlorobenzene sprayes per kilogramme of carcass. From 6.8 -10.8 grammes of o-dichlorobenzene sprayed per kilogramme of carcass in a 20 -% solution in fuel oil, which is ineffective on its own, had the same larvicidal action.

A study of the larvicidal action on the meatfly larva, Sarcophaga peregrina ROBINEAU-DESVOIDY, yielded LC50 and LC99 values of ca. 1.4 g/L and ca. 2.8 g/L respectively for 24 hours contact with o-dichlorobenzene emulsions and a 24 -hour follow-up period.

In vitro tests of toxicity to mites (Tyrophagus dimidiatus) revealed that exposure for 1 minute and 4 minutes to o-dichlorobenzene in a concentration of 10 g/L (the solution contained water and 4% (w/w) of Tween 20) resulted in the deaths of 50% and 100% respectively of the specimens.

The toxic effect of o-dichlorobenzene on aphids of the speciesAphis rumicisL. were also investigated. Spraying of an emulsion preparation containing 10 g/L of o-dichlorobenzene induced death in 10% of the specimens (adult, apterous, agamic females). o-Dichlorobenzene proved 100% fatal in concentrations of at least 40 g/L.

In studies o fthe toxicity to eggs of the geometrid moth,Selenia tetralunariaHUFN, emulsified o-dichlorobenzene sprayed in concentrations of at most 50 g/L did not prove toxic.

The effects on the termites,Postelectrotermes militaris(DESNEUX; =Neotermes militarisDESNEUX), that infest the roots and trunk of the tea plant was investigated in a field trial. The galleries in the wood of the infested tea plant were gassed with 10 mL o-dichlorobenzene per plant (the gallery system is accessed by cutting the branch) and the openings were sealed with clay or putty. One week after treatment, the mortality rate was found to be 10.6%.

Combating of termites by treating the soil with o-dichlorobenzene proved not to be very successful in the practicable concentrations and applied amounts. Thus, treatment with as much as 17.5 kg/m3 of soil yielded erratic results. However, effective control was obtained with 123 kg/m3.

Exposure for 16.7 h at 15°C of wireworm larvae of the genusAgriotesto 10.2 g/m3 of o-dichlorobenzene present in vapour form in damp air proved lethal. Larvae exposed to 7 g/m3 of o-dichlorobenzene for the same length of time recovered on cessation of exposure.

The brood of the Douglas-fir beetle (Dendroctonus pseudotsugaeHOPKINS) was effectively controlled in standing trees or logs by spraying them with o-dichlorobenzene in diesel oil in a volume ratio of 1:3 or 1:5. Application of approximately 30 or 40 mg of o-dichlorobenzene per cm2 of bark yielded a mortality rate of 100%. The reason for this high application rate in Douglas firs is the ability of the bark of these trees to absorb 2 -3 times more of the oily preparations relabive to the bark of other conifers.

With a view to controlling the Engelmann spruce beetle (Dendroctonus engelmanniHOPKINS), standing trees and logs were treated similarly with a solution of 200 g/L of o-dichlorobenzene in fuel oil. Mortality rates of 95 -98% were recorded.

In an oil-in-water emulsion containing 20% (v/v) fuel oil, o-dichlorobenzene, present in a concentration of 20 g/L emulsion, proved lethal to the larvae and pupae of the mountain pine beetle,Dendroctonus monticolaeHOPKINS whereas 77% of the young adults survived. The brood survival rate was 63% when a concentration of 30 g/L of emulsion (containing 33% (v/v) fuel oil) was used.

When the trunk of the locust tree (Robinia pseudoacaciaL.) was sprayed with emulsions containing at least 8% o-dichlorobenzene, a 100% mortality rate was recorded fo the larvae of the locust borer,Cyllene robiniaeFORST. In contrast, an 8% o-dichlorobenzene emulsion was not fatal to the larvae of the codling moth,Carpocapsa pomonella.

After injecting o-dichlorobenzene into grapevine stems infested with larvae of the wasp beetle,Chlorophorus variusMULL, a 75% mortality rate among those larvae immediatley beneath the bark was determined.

Sprayed o-dichlorobenzene acts as a direct-contact insecticide for skins and hides infested with the hide beetle,Dermestes vulpiusFAB., and its larvae as well as for the webbing clothes moth of the speciesTineola biselliellaHUM., proving fatal within 10 -15 minutes.

Twenty four hours exposure to 40 g/m3 of o-dichlorobenzene in vapour form did not have any lethal effect on the flour weevil,Tribolium confusumFAB., the Indian meal moth,Plodia interpunctellaHBN., the rice weevil,Sitophilus oryzaL., and the granary weevil,Sitophilus granariusL.

ForCalandra oryzaeL., LC50 and LC95 values of 17 -19 g/m3 and 30 -33 g/m3 were determined. The corresponding values forCalandra sasakiiTAKAHASHI were reported to be 6 -8 g/m3 and 12 -18 g/m3. The lower values in each case pertain to weevils that had a higher fat content owing to their having been nourished on a diet richer in fat. It was concluded from this finding that o-dichlorobenzene is absorbed into the insect's body fat and is thus eliminated more slowly.

Five hours exposure of rice weevils,Calandra oryzaeL., to concentrations of o-dichlorobenzene greater than 5 g/m3 led to paralysis and death.