@article {46234, title = {Spatial distribution and spread of sheep biting lice, Bovicola ovis, from point infestations}, journal = {Veterinary parasitology}, volume = {81}, year = {1999}, note = {LR: 20041117; JID: 7602745; ppublish}, month = {1999}, pages = {323 - 339}, abstract = {

The spatial distribution of chewing lice (Bovicola ovis) on their hosts was examined in Polypay and Columbia ewes initially artificially infested on the midside or the neck. Densities of lice were determined at 69 body sites in eight body regions at approximately monthly intervals for 2 years. In the second year, half of the ewes were mated and lice were counted at 26 body sites on the resulting lambs. Polypay ewes had higher densities of lice than Columbias at most inspections but there was little effect of infestation point or mating on either numbers or the distribution of lice. During periods of high louse numbers densities were generally greatest on the sides or the back. Densities on the head were also high at times and peaked later than overall louse densities. Shearing markedly reduced density but increased the proportion of lice found on the neck, belly and lowleg sites. The distribution of lice on the lambs was similar to that on the ewes except that fewer lice were found on the head. Comparisons of lice per part with the numbers of lice extracted from clipped patches indicated that a sheep with wool bearing area of 1 m2 and a mean count of one louse per 10 cm fleece parting carried approximately 2000 lice. At most times of the year inspections for sheep lice should be concentrated on the sides and back, but in recently shorn sheep greater attention should be paid to the lower neck and ventral regions. Implications of the observed distributions of lice for the efficacy of chemical treatments are discussed.

}, keywords = {abdomen, Analysis of Variance, animals, Back/parasitology, head, Lice Infestations/parasitology/veterinary, Linear Models, Mallophaga, Research Support, Non-U.S. Gov{\textquoteright}t, sheep, Sheep Diseases/parasitology, Skin/parasitology, wool}, isbn = {0304-4017}, doi = {https://doi.org/10.1016/S0304-4017(98)00259-3}, url = {https://www.sciencedirect.com/science/article/pii/S0304401798002593?via\%3Dihub}, author = {Peter J. James and Moon,R. D.} } @article {46227, title = {Prevalence and clustering of louse infestation in Queensland sheep flocks}, journal = {Veterinary parasitology}, volume = {82}, year = {1999}, note = {LR: 20031114; JID: 7602745; ppublish}, month = {1999}, pages = {243 - 250}, address = {NETHERLANDS}, abstract = {Information provided by wool growers in Queensland, Australia between 1995 and 1997 was used to assess the prevalence and spatial distribution of louse (Bovicola ovis) infestation in sheep flocks. The estimated prevalence of louse-infested flocks was 40\% (95\% confidence interval, 35-46\%). Although the prevalence of infestation was higher in western regions (41-50\%) compared to the south region of Queensland (31\%), the difference was not statistically significant (P > 0.05). Significant (P = 0.02) clustering of infested flocks was detected in the south region where two foci were apparent. We conclude that Queensland sheep flocks have a moderate prevalence of louse infestation, and that clustering of infestation is not strong. The control of lice is an industry-wide issue that needs to be addressed by most wool growers in Queensland.}, keywords = {animals, Lice Infestations/epidemiology, Lice/growth \& development, Prevalence, Queensland, sheep, Sheep Diseases/epidemiology/parasitology, wool}, isbn = {0304-4017}, author = {Ward,M. P. and Armstrong,R. T.} } @article {46216, title = {Do sheep regulate the size of their mallophagan louse populations?}, journal = {International journal for parasitology}, volume = {29}, year = {1999}, note = {LR: 20041117; JID: 0314024; 0 (Antibodies); RF: 54; ppublish}, month = {1999}, pages = {869 - 875}, address = {ENGLAND}, abstract = {

Alternatives to chemicals for controlling parasites are required to minimise problems from resistance, residues in animal products and occupational exposure. Utilisation of host response to parasites through selection of resistant types or vaccination is an appealing option. To date most studies have been with haematophagous or invasive parasites which directly contact elements of the host immune system. Sheep lice (Bovicola ovis) feed superficially on the skin of sheep ingesting lipid, scurf, bacteria and loose stratum corneum squames. Evidence is presented that despite their surface feeding habit Bovicola ovis stimulate an immune response in sheep and that this response may play a part in regulating the size of louse populations.

}, keywords = {animals, Antibodies/immunology, hypersensitivity, Lice Infestations/immunology/parasitology/veterinary, Mallophaga, Research Support, Non-U.S. Gov{\textquoteright}t, sheep, Sheep Diseases/immunology/parasitology}, isbn = {0020-7519}, doi = {https://doi.org/10.1016/S0020-7519(99)00055-7}, url = {https://www.sciencedirect.com/science/article/pii/S0020751999000557?via\%3Dihub}, author = {Peter J. James} } @article {39778, title = {Genetic structure of the Bovicola ovis (Mallophaga : Trichodectidae) in southwestern Australia}, journal = {Environmental Entomology}, volume = {28}, year = {1999}, month = {1999}, pages = {675 - 680}, abstract = {

The sheep biting louse, Bovicola ovis (Schrank), is an economically important, worldwide ectoparasite of sheep. In Australia, up to 30\% of sheep flocks are infested with lice. The usual method of control has been synthetic pyrethroids applied as pour-on along the back of the sheep, but treatment failures have become widespread since 1985 because of the development of resistance. We used allozyme markers to study the distribution of genetic variation within and among populations of lice on different farms in Western Australia. Genetic variation within populations was similar to previously reported values for other ectoparasitic arthropods. Heterozygote deficiencies were found at 1 locus ina number of population acid another 2 loci in 1 other population. However, another variable locus conformed to Hardy-Weinberg equilibrium and there was little evidence of extensive linkage disequilibrium between loci, Further studies are necessary to establish the breeding system. Genetic differences among populations were not related to geographic separation, which is consistent with an island model of population structure. A small but significant proportion (2.8\%) of the total genetic variation was distributed among populations\&$\#$39; equivalent under the island model to a gene flow of 8.7 individuals exchanged per generation. The implications of this result are discussed in terms of controlling and managing synthetic pyrethroid resistance in sheep biting lice.

}, keywords = {differentiation, Evolution, flow, frequencies, genes, genetics, insecticide, lice, Phthiraptera, populations, Pyrethrum, resistance, sheep, snail}, url = {http://www.phthiraptera.info/sites/phthiraptera.info/files/37959.pdf}, author = {Lymbery,Alan J. and Dadour,Ian R.} } @article {39570, title = {Spermatogenesis in Bovicola limbata Gervais, 1844 and B. caprae Gurlt, 1843 (Phthiraptera: Ischnocera)}, journal = {Cytologia (Tokyo)}, volume = {64}, year = {1999}, month = {1999}, pages = {25 - 27}, author = {Tombesi,M. L. and Papeschi,A. G. and Mola,L. M.} }