Title: Ovicidal and Adulticidal Activity of Eucalyptus Globulus Leaf Oil Terpenoids Against Pediculus humanus capitis (Anoplura: Pediculidae).
Author: Yang, Y.C.; Choi, H.Y.; Choi, W.S.; Clark, J.M.; Ahn, Y.J.*
Source: Journal of Agricultural and Food Chemistry, 2004 May 5, v. 52, no. 9, p. 2507-2511.
Abstract: The toxic effects of Eucalyptus globulus leaf oil-derived monoterpenoids [1,8-cineole, l-phellandrene, (-)-alpha-pinene, 2-beta-pinene, trans-pinocarveol, gamma-terpinene, and 1-alpha-terpineol] and the known Eucalyptus leaf oil terpenoids (beta-eudesmol and geranyl acetate) on eggs and females of the human head louse, Pediculus humanus capitis, were examined using direct contact and fumigation bioassays and compared with the lethal activity of delta-phenothrin and pyrethrum, two commonly used pediculicides. In a filter paper contact bioassay with female P. h. capitis, the pediculicidal activity was more pronounced with Eucalyptus leaf oil than with either delta-phenothrin or pyrethrum on the basis of LT50 values (0.125 vs 0.25 mg/cm2). 1,8-Cineole was 2.2- and 2.3-fold more toxic than either delta-phenothrin or pyrethrum, respectively. The pediculicidal activities of (-)-alpha-pinene, 2-beta-pinene, and (E)-pinocarveol were comparable to those of delta-phenothrin and pyrethrum. l-Phellandrene, gamma-terpinene, and 1-alpha-terpineol were relatively less active than delta-phenothrin and pyrethrum. beta-Eudesmol and geranyl acetate were ineffective. 1-alpha-Terpineol and (E)-pinocaveol were highly effective at 0.5 and 1.0 mg/cm2, respectively, against P. h. capitis eggs. At 1.0 mg/cm2, (-)-alpha-pinene, 2-beta-pinene, and gamma-terpinene exhibited moderate ovicidal activity, whereas little or no ovicidal activity was observed with the other terpenoids and with delta-phenothrin and pyrethrum. In fumigation tests with female P. h. capitis at 0.25 mg/cm2, 1,8-cineole, (-)-alpha-pinene, (E)-pinocarveol, and 1-alpha-terpineol were more effective in closed cups than in open ones, indicating that the effect of the monoterpenoids was largely due to action in the vapor phase. Neither delta-phenothrin nor pyrethrum exhibited fumigant toxicity. Eucalyptus leaf oil, particularly 1,8-cineole, 1-alpha-terpineol, and (E)-pinocaveol, merits further study as potential pediculicides or lead compounds for the control of P. h. capitis.
Descriptors: Eucalyptus globulus; leaves; essential oils; pesticidal plants; insecticidal properties; ovicides; adulticides; Pediculus humanus capitis; lice; insect pests; ova; structure-activity relationships; terpenoids; monoterpenoids
Identifiers: pediculicidal activity
ISSN: 00218561
Category Codes: Pests of Animals (Insects and Other Arthropods); Human Medicine, Health, and Safety; Agricultural Products (Plant)
Call Numbers: NAL Call Number. 381 J8223
Database: Agricola

*The author(s) cited above are not in any way affiliated with Rainforest Essentials. Their citation is offered solely for informational purposes and not to be construed as an endorsement of Lice Off!™ in particular or any of our products in general.