02399nas a2200277   4500008004100000020001400041245009700055210006900152260000900221300001400230490000700244520146100251653001201712653002101724653002001745653004601765653001501811653003501826653001001861653003201871653003701903100002101940700001901961700001501980856012601995       1989                        eng d  a0304-401700aFeeding of the chewing louse Damalinia ovis (Schrank) (Phthiraptera:Trichodectidae) on sheep0 aFeeding of the chewing louse Damalinia ovis Schrank Phthiraptera  c1989  a233 - 2510 v303 aThe possibility that Damalinia ovis ingests intact epidermis could explain economically important irritation behaviour by infested sheep. To test this, feeding lice were observed on sheep by hand lens and macrophotography and on light and scanning electron microscope preparations. Aspects of feeding behaviour were described, particularly an epidermal ingestion posture. Louse ingesta were examined in paraffin and frozen sections. Lipid-covered stratum corneum squames were identified in crop, midgut, rectum and faeces. Nucleated keratinocytes from inner epidermal strata were not seen, neither were wool fibres. Vertical frozen sheep skin sections, with feeding lice cryofixed by liquid nitrogen, showed mandibles engaged in the outer stratum corneum of the epidermis. The epidermal origin of some ingesta was confirmed by confirming lice over sheep whose skin was stained with Oil Red O, whose colour was seen in crop, midgut, rectum and faeces of harvested lice. Lipase was found in louse midgut. It was concluded that sebaceous secretions may form an important component of the D. ovis diet. The relative contribution from loose scurf or from stratum corneum squames was not determined. Mechanical stimuli by feeding lice did not seem to be the source of host irritation. The role of sensitising agents in louse brei filtrates was investigated with inconclusive results. Intradermal injections of louse faeces did not elicit a demonstrable response.10aanimals10aFeeding Behavior10aFrozen Sections10aLice Infestations/parasitology/veterinary10aMallophaga10aMicroscopy, Electron, Scanning10asheep10aSheep Diseases/parasitology10aSkin/parasitology/ultrastructure1 aSinclair, A., N.1 aButler, R., W.1 aPicton, J.  uhttps://phthiraptera.myspecies.info/content/feeding-chewing-louse-damalinia-ovis-schrank-phthirapteratrichodectidae-sheep02435nas a2200289   4500008004100000020001400041245013300055210006900188260001800257300001400275490000700289520147300296653001201769653002401781653002101805653004601826653001501872653002301887653003701910653001001947653003201957653002001989100002102009700001702030700002102047856007702068       1998                        eng d  a0269-283X00aSerum and skin surface antibodies and their associations with sheep biting lice, Bovicola ovis, on experimentally infested sheep0 aSerum and skin surface antibodies and their associations with sh  aENGLANDc1998  a276 - 2830 v123 a<p>The sheep biting louse (Bovicola ovis) feeds superficially on the skin of sheep but appears to stimulate an immune response. In this study we examined the association between louse infestation and serum and skin surface antibodies. Louse numbers were monitored on experimentally infested Polypay and Columbia ewes for two years and on their lambs in the second year. Serum and skin wash samples were tested for antibodies to soluble extracts of B. ovis, Stomoxys calcitrans and Musca autumnalis by enzyme linked immunosorbent assay (ELISA). In addition, the effects of skin wash extracts on B. ovis were examined in vitro. The titre of anti-B. ovis antibodies in the serum did not differ significantly between infested and naive ewes. However, there was an increase in serum antibody titre which coincided with periods of high louse density in ewes with high louse counts. Infested lambs had higher serum antibody levels than naive lambs. Substantial cross reactivity was evident among extracts of the different insects. Densities of lice on the ewes during population decline were negatively related to the titre of skin surface antibodies. Skin washings collected from sheep during B. ovis population decline reduced the number of louse progeny when incorporated into louse diet. These results indicate that B. ovis stimulates an immune response in sheep and suggest that compounds on the skin surface may play a role in the regulation of louse populations.</p>
10aanimals10aAntibodies/analysis10aBiological Assay10aLice Infestations/parasitology/veterinary10aMallophaga10apopulation density10aResearch Support, Non-U.S. Gov't10asheep10aSheep Diseases/parasitology10aSkin/immunology1 aJames, Peter, J.1 aMoon, R., D.1 aRagsdale, D., W.  uhttps://onlinelibrary.wiley.com/doi/abs/10.1046/j.1365-2915.1998.00110.x02510nas a2200313   4500008004100000020001400041245009700055210006900152260000900221300001400230490000700244520155500251653001201806653002501818653001201843653002201855653000901877653004601886653001801932653001501950653003701965653001002002653003202012653002202044653000902066100002102075700001702096856008302113       1999                        eng d  a0304-401700aSpatial distribution and spread of sheep biting lice, Bovicola ovis, from point infestations0 aSpatial distribution and spread of sheep biting lice Bovicola ov  c1999  a323 - 3390 v813 a<p>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.</p>
10aabdomen10aAnalysis of Variance10aanimals10aBack/parasitology10ahead10aLice Infestations/parasitology/veterinary10aLinear Models10aMallophaga10aResearch Support, Non-U.S. Gov't10asheep10aSheep Diseases/parasitology10aSkin/parasitology10awool1 aJames, Peter, J.1 aMoon, R., D.  uhttps://www.sciencedirect.com/science/article/pii/S0304401798002593?via%3Dihub