Field Evaluation of Deltamethrin and Ivermectin Applications to Cattle on <i>Culicoides</i> Host-Alighting, Blood-Feeding, and Emergence
The impact of topical applications of deltamethrin and ivermectin to cattle on <i>Culicoides</i> spp. landing and blood-feeding was studied in this work using sticky traps mounted on Friesian heifers’ backs. There was no effect of the insecticides on total numbers of <i>C...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2019-08-01
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| Series: | Viruses |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1999-4915/11/8/731 |
| Summary: | The impact of topical applications of deltamethrin and ivermectin to cattle on <i>Culicoides</i> spp. landing and blood-feeding was studied in this work using sticky traps mounted on Friesian heifers’ backs. There was no effect of the insecticides on total numbers of <i>Culicoides</i> trapped or the proportion engorged. Deltamethrin and ivermectin treatment did not prevent blood-feeding on these animals. Deltamethrin did result in significant <i>Culicoides</i> mortality as evidenced by the numbers of dead midges combed from heifers’ upper flanks. The proximity of engorged midges on traps to dead midges in the hair suggests that blood-feeding took place despite midges receiving an ultimately lethal dose of deltamethrin. Ivermectin application resulted in a smaller proportion of nulliparous than parous females caught. There was no significant effect of ivermectin on the numbers of <i>Culicoides</i> that emerged from dung samples (but <i>p</i> was small at 0.095 for the Obsoletus group <i>Culicoides</i>). In cases of suspect animal imports, pour-on or spray applications of deltamethrin could reduce the risk of onward transmission of bluetongue virus. |
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| ISSN: | 1999-4915 |