title: Adulticidal activity of phthalides identified in Cnidium officinale rhizome to B- and Q-biotypes of Bemisia tabaci.
abstract: The residual contact toxicity of three benzofuranoids (Z)-butylidenephthalide (1), (3S)-butylphthalide (2), and (Z)-ligustilide (3) identified in the rhizome of Cnidium officinale (Apiaceae) to B- and Q-biotype females of Bemisia tabaci was evaluated using a leaf-dip bioassay. Results were compared with those of eight conventional insecticides. Based on 24 h LC(50) values, (Z)-butylidenephthalide (254 ppm) and (Z)-ligustilide (268 ppm) were more toxic than (3S)-butylphthalide (339 ppm) against B-biotype females, whereas (Z)-ligustilide (254 ppm) and (3S)-butylphthalide (338 ppm) were more toxic than (Z)-butylidenephthalide (586 ppm) against Q-biotype females. Thiamethoxam, imidacloprid, and acetamiprid differ significantly in toxicity between the B- and Q-biotype females (LC(50), 1.7 to 11.6 vs 364.5 to >3000 ppm). This original finding indicates that the phthalides and the neonicotinoids do not share a common mode of action or elicit cross-resistance. Structure-activity relationship indicates that the presence of conjugation rather than aromaticity appeared to play an important role for phthalide toxicities to the B-biotype females. Global efforts to reduce the level of highly toxic synthetic insecticides in the agricultural environment justify further studies on C. officinale rhizome-derived materials as potential insecticides for the control of B. tabaci populations.
authors: Department of Agricultural Biotechnology, Seoul National University, Seoul, Republic of Korea.
authors: Song-Hwa
authors: SH
authors: Chae
authors: Soon-Il
authors: SI
authors: Kim
authors: Seong-Hum
authors: SH
authors: Yeon
authors: Si-Woo
authors: SW
authors: Lee
authors: Young-Joon
authors: YJ
authors: Ahn
mesh_terms: D000818:Animals; D001572:Benzofurans / Q000737:chemistry* / Q000633:toxicity; D031048:Cnidium / Q000737:chemistry*; D005260:Female; D006430:Hemiptera / Q000145:classification / Q000187:drug effects*; D007306:Insecticides / Q000737:chemistry* / Q000633:toxicity; D008297:Male; D010936:Plant Extracts / Q000737:chemistry* / Q000633:toxicity; D027343:Rhizome / Q000737:chemistry*; D013329:Structure-Activity Relationship
chemical_list: D001572:Benzofurans; D007306:Insecticides; D010936:Plant Extracts; C082022:phthalide