Linked Life Data

20079571

Source:http://linkedlifedata.com/resource/pubmed/id/20079571

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
2010-3-23
pubmed:abstractText
A farmlet study was conducted over 4 years in which three treatments were applied to six groups of Holstein dairy calves. Calves in each group were infested with equal numbers of N-strain (susceptible) and Ultimo strain (amitraz and synthetic pyrethroid resistant) tick larvae to establish self-sustaining populations with an initial, measurable level of resistance to amitraz. Standard counts of all ticks between 4.5 and 8.0mm diameter on one side of each animal were made each week and treatment was applied when tick numbers exceeded a threshold of 25 engorged adults per side. The three treatments were: 1, spinosad spray whenever tick numbers exceeded the threshold; 2, amitraz spray whenever tick numbers exceeded the threshold; 3, spinosad whenever tick numbers exceeded the threshold for the first 2 months, then amitraz for 2 months, with alternation every subsequent 2 months. Engorged adult female ticks were collected from each treatment group on 10 or 11 occasions during the study and tested using the larval packet test bioassay (LPT) for acaricide resistance. Spinosad 250ppm provided effective control of amitraz-resistant tick populations in the field, using a similar number of treatments as in the amitraz and rotation groups. The initial infestations of all of the groups resulted in the establishment of populations with in vitro evidence of resistance to amitraz using the LPT. Treatment with spinosad or with a rotation between spinosad and amitraz every 2 months resulted in reduced levels of resistance to amitraz according to the LPT. The animals treated with amitraz alone showed increasing resistance to amitraz according to the LPT each summer and autumn with a return to full or almost full susceptibility to amitraz in early spring in all years. This pattern suggests a relative lack of fitness of amitraz-resistant ticks that might be exploited by using an acaricide rotation strategy.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
1873-2550
pubmed:author
pubmed:issnType
Electronic
pubmed:day
19
pubmed:volume
169
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
157-64
pubmed:meshHeading
pubmed:year
2010
pubmed:articleTitle
Rotation of treatments between spinosad and amitraz for the control of Rhipicephalus (Boophilus) microplus populations with amitraz resistance.
pubmed:affiliation
The University of Queensland, School of Veterinary Science, Qld, Australia. n.jonsson@vet.gla.ac.uk
pubmed:publicationType
Journal Article