LABORATORY STUDIES ON RESISTANCE TO CYPERMETHRIN IN <i>DAMALINIA OVIS</i> (SCHRANK) (PHTHIRAPTERA: TRICHODECTIDAE)

Levot, G. W.; Hughes, P. B.

doi:10.1111/j.1440-6055.1990.tb00358.x

Cited by 42 publications

(27 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Table 1. Responses of Damalinia ovis to cypermethrin and avermectins, assessed using a wool/skin/cloth bioassay, and that of Levot and Hughes (1990 Levot and Hughes (1990), 2 = Modified wool/skin/cloth bioassay. Number of lice tested.…”

Section: Resultsmentioning

confidence: 99%

“…This assay cannot be directly compared to that of Levot and Hughes (1990) due to the incorporation of the wool/skin substrate and the different temperature and humidity conditions. The LCso for cypermethrin was significantly higher (as indicated by non-overlap of 95% Fiducial limits) in the modified assay.…”

Section: Discussionmentioning

confidence: 99%

“…The difference in results for cypermethrin between assays may be due to a number of factors, including assay conditions, but possibly relates to the dilution effect of the added substrate. For fastacting compounds the contact assay of Levot and Hughes (1990) is a quick and convenient method of comparative assessment. The modified assay is suitable for slower-acting compounds and also may reflect more closely the in vivo situation since the selected conditions are similar to those at skin level of sheep.…”

Section: Discussionmentioning

confidence: 99%

See 2 more Smart Citations

Untitled

1993

Australian Journal of Entomology

View full text Add to dashboard Cite

A bioassay suitable for the determination of dose responses of the sheep body louse, Damuliniu ovis, to avermectins is described. The inclusion of wool/skin substrate resulted in approximately 90% survival of controls over the 48-h test period. Ivermectin and abamectin were highly effective against D . ovis, and similar responses of pyrethroid-susceptible and resistant strains indicated that there was no cross-resistance to ivermectin. IntroductionThe sheep body louse, Damalinia ovis (Schrank), an important ectoparasite of sheep (Arundel and Sutherland 1988), has developed resistance to synthetic pyrethroid insecticides used as pour-ons for louse control (Boray et al. 1988). Ivermectin is highly toxic to larvae of the Australian sheep blowfly, Lucilia cuprina (Wiedemann) , and when applied to sheep as a jetting fluid for fly control shows promise for reducing infestations of D. ovis (unpublished data). However, the laboratory responses of pyrethroid resistant and susceptible lice to ivermectin have not yet been evaluated.The resistance status of D. ovis to pyrethroids can be determined in a laboratory bioassay suitable for any fast-acting contact insecticide ). This assay is not suitable for testing avermectins since these compounds are generally slow acting (Strong and Brown 1987) and more effective through ingestion than by contact action (Lasota and Dybas 1991). Hopkins (1970) successfully maintained an in vitro colony of D. ovis for more than 10 months on a wool/skin substrate held at 37°C and 68% RH. Here, we describe a bioassay modified by the inclusion of wool/skin substrate which is suitable for testing slow-acting compounds such as avermectins, present data on the laboratory efficacy of ivermectin and abamectin against D. ovis, and examine the toxicity of ivermectin to a pyrethroid-sensitive and a resistant population of D. ovis.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Untitled

1993

Australian Journal of Entomology

View full text Add to dashboard Cite

show abstract

“…The deregistration of arsenic and the development of synthetic pyrethroid (SP) resistance (Levot and Hughes 1990) renewed interest i n organophosphate (OP) dips for lice control on sheep. O P products have been registered for this purpose since the mid-1950s in Australia and have been in continual use, not only for lice control, but for flystrike preventiodtreatment as well.…”

Section: Introductionmentioning

confidence: 99%

A Survey of Organophosphate Susceptibility in Populations of Bovicola ovis (Schrank) (Phthiraptera: Trichodectidae)

Levot¹

1994

Australian Journal of Entomology

View full text Add to dashboard Cite

A toxicological survey of 28 field populations of the sheep body louse, Bovicola ovis, identified only one strain whose response to diazinon was recognisably separate from the normally distributed responses of the other strains. The resistance factor (at LC50) of this strain was about 9 times. Resistance to diazinon correlated positively with resistance to coumaphos, but not to propetamphos. The lack of correlation between strain resistances to diazinon and cypermethrin indicates that organophosphate chemicals can be recommended to woolgrowers whose flocks are infested by pyrethroid-resistant lice. Conversely, the results presented here suggest that, at least for the diazinon-resistant strain, a pyrethroid or propetamphos treatment would be the most appropriate control option.

show abstract

“…The efficacy of chemical control of lice resulted in few alternatives having been considered 9 . Resistance of B. ovis to synthetic pyrethroid (SP) backline products was reported as early as 1987 15 . By 1998, in Australia, 90 % of the western Queensland louse population had become resistant to SP compounds (Ward and Armstrong, 1999, as cited by James 9 ).…”

mentioning

confidence: 99%

Infestation with the sheep body louse (Bovicola ovis) in Merino lines divergently selected for maternal multiple rearing ability : short communication

Cloete¹,

Laubscher²,

Cloete³

2003

J. S. Afr. Vet. Assoc.

View full text Add to dashboard Cite

Data were obtained from a population consisting of 160 Merino ewes, as well as 64 male and 75 female progeny of these ewes at the 2-tooth age. The age and sex groups were maintained in separate flocks. The population has been divergently selected from the same base since 1986, either for (high or H line) or against (low or L line) maternal multiple rearing ability. All animals were inspected for sheep lice (Bovicola ovis) during September / October 2002 after a wool growth period of at least 4 months. When expressed relative to mean L-line performance, the advantage in lambs weaned per ewe during the lambing season amounted to approximately 110 % in the H line (1.01 vs 0.48; P < 0.01). The proportion of animals on which 1 or more lice were observed were markedly lower in 2-tooth replacement ewes than in replacement rams and mature breeding ewes (0.053 vs 0.625 and 0.531, respectively; P < 0.01). One or more lice were observed on a lower proportion of H-line ewes than on those of the L line (0.413 vs 0.571, respectively; P < 0.10), while a similar tendency was observed in 2-tooth ewe hoggets (0.033 vs 0.143, respectively; P =0.16). When the mean number of lice on individuals on which 1 or more lice were observed was compared between lines, the average number of lice observed on H-line young rams was lower than in the L line (4.36 Â± 0.85 vs 9.71 Â± 1.84 lice, respectively; P < 0.01). A similar tendency was observed in mature breeding ewes (2.15 Â± 0.38 vs 3.22 Â± 0.42 lice, respectively; P < 0.20). The more highly reproductive H-line ewes were not more susceptible to infestation with B. ovis than ewes of the L line. In fact, available evidence suggest that H-line animals could be more tolerant of B. ovis than those of the L line.

show abstract

LABORATORY STUDIES ON RESISTANCE TO CYPERMETHRIN IN DAMALINIA OVIS (SCHRANK) (PHTHIRAPTERA: TRICHODECTIDAE)

Cited by 42 publications

References 2 publications

Untitled

Untitled

A Survey of Organophosphate Susceptibility in Populations of Bovicola ovis (Schrank) (Phthiraptera: Trichodectidae)

Infestation with the sheep body louse (Bovicola ovis) in Merino lines divergently selected for maternal multiple rearing ability : short communication

Contact Info

Product

Resources

About