Increased control of the sheep biting louse Bovicola (Damalinia) ovis with deltamethrin formulated in a fractionated wool grease carrier
Fri, 2007-02-02 15:01 — Vince Smith
| Title | Increased control of the sheep biting louse Bovicola (Damalinia) ovis with deltamethrin formulated in a fractionated wool grease carrier |
| Publication Type | Journal Article |
| Year of Publication | 2000 |
| Authors | Hennessy, DR, Darwish A, Maxwell CA |
| Journal | Veterinary parasitology |
| Volume | 89 |
| Pages | 117-127 |
| Journal Date | Mar 28 |
| Accession Number | 45007 |
| Keywords | Animals; Insect Control ; insecticide ; Lice Infestations/prevention & control/veterinary ; Mallophaga ; Oils ; Pyrethrum ; Research Support, Non-U.S. Gov't ; Sheep ; Sheep Diseases/prevention & control ; Wool |
| Abstract | The synthetic pyrethroid deltamethrin (DM) containing a trace of [(14)C]-DM was formulated with non-oxidised sterol and wax ester fractions (F1) of wool grease and as the commercial preparation 'Clout-S'. These were applied as a 'backline' strip to sheep immediately after shearing and the concentration of [(14)C]-DM at meridians adjacent to the application strip and at 1/4 and 3/4 of the dorsal-ventral distance was determined. The F1 formulation resulted in significantly greater lateral spread of DM with less remaining at the application site (66+/-8% of dose) 98 days after treatment compared to 'Clout-S' (94+/-3% dose). Autoradiographic examination of treated wool demonstrated that there was more DM in the lower half of the wool staple when formulated in F1 compared to 'Clout-S'. Greater mortality occurred when sheep biting lice Bovicola (Damalinia) ovis were exposed in vitro to wool containing DM from F1 compared to 'Clout-S' treated sheep. In field trials there was increased efficacy against synthetic pyrethroid resistant B. ovis with F1 formulation than with 'Clout-S'. The study has demonstrated that synthetic pyrethroid availability, and therefore efficacy, can be significantly increased when the insecticide is formulated in a 'carrier' with the physicochemical characteristics of wool grease. |
