Evaluation of the acaricidal toxicities of camphor and its structural analogues against house dust mites by the impregnated fabric disc method.

Background: The acaricidal activities of (±)-camphor structural analogues against house dust mites were evaluated using the impregnated fabric disc bioassay.

Results: The acaricidal effects of camphor and its structural analogues were evaluated against Dermatophagoides farinae and D. pteronyssinus. Based on the LD50 values against D. farinae, (±)-camphor (0.95 µg cm(-2) ) was 38.75 times more effective than N,N-diethyl-m-toluamide (DEET) (36.81 µg cm(-2) ), followed by (+)-camphor (1.41 µg cm(-2) ), (-)-camphor (2.03 µg cm(-2) ) and (1R)-camphor oxime (3.31 µg cm(-2) ) in the impregnated fabric disc bioassay. However, camphor-10-sulfonic acid and camphoric acid had no observable activity against D. farinae or D. pteronyssinus. The acaricidal activities of camphor and its structural analogues against D. pteronyssinus were similar to those against D. farinae.

Conclusion: These results indicate that camphor and its structural analogues are suitable for producing acaricidal agents against house dust mites.