“…When compared with dichlorvos (LC 50 = 1.35 μg/L), the essential oil of B. frondosa and 4-terpineol showed only 375 times and 248 times less toxicity against L. bostrychophila, respectively. However, the essential oil of B. frondosa demonstrated a stronger fumigant toxicity against booklice than several essential oils using the same bioassay, e.g., Artemisia rupestris (LC 50 = 6.67 mg/L air) [11], A. frigida (LC 50 =1.25 mg/L) [12], C. wenyujin (LC 50 = 2.76 mg/L) [13], V. jatamansi (LC 50 = 6.0 mg/L) [15], and K. galangal (LC 50 = 1.5 mg/L air) [17], but the oil of B. frondosa demonstrated less toxicity than the essential oils of Allium chinense (LC 50 = 186.5 g/L air) [18] and F. vulgare fruits (LC 50 = 34.07 μg/L) [14]. However, the currently commercial fumigants (e.g.…”