Abstract
This study investigated the effects of Igusa (Juncus effusus var. decipiens) varieties and aging on the intrusion behavior of Dermatophagoides pteronyssinus, and evaluated a novel mite control method using nonwoven fabric impregnated with 2-butyloctanoic acid (iso-C12) as mite-repellent paper. The intrusion prevention rates for Igusa of Hinomidori, Hinoharuka, and Yunagi were extremely high, at 98.3%, 96.3%, and 93.9%, respectively. However, after one month of sunlight exposure and discoloration, the prevention effect decreased to below 62.5%. Attraction tests using fabrics of different colors did not reveal any relationship with mite behavior, indicating that the preventive effect of Igusa is not visual but is likely related to volatile compounds that diminish over time. The iso-C12-impregnated nonwoven fabric achieved nearly 100% intrusion prevention even at 0.78 v/v%. In simplified Tatami experiments under non-contact conditions, prevention rates of 81–87% were obtained. These results demonstrate that placing iso-C12-impregnated nonwoven fabric beneath Tatami-omote is a practical and effective mite control strategy that minimizes resident exposure while preventing mite invasion into indoor living spaces.
