Keywords : Oestrus ovis


Morphological and phylogenetic characterization of Oestrus ovis larvae in sheep: Al-Qadisiyah province, Iraq

Nadia S. Alhayali; Mohenned A. Alsaadawi; Monyer A. Al-Fatlawi; Mansoor J. Alkhaled

Iraqi Journal of Veterinary Sciences, 2022, Volume 36, Issue 1, Pages 133-137
DOI: 10.33899/ijvs.2021.129529.1656

The fly larvae infect the nasal cavities and sinuses (frontal and maxillary) of sheep, goats, and a range of wild ruminants, forming a disease called oestrosis (Nasal myiasis or nasal bot). The disease is one of the significantly diseases for the Iraqi small ruminant industry that causes detrimental economic losses. The current work was carried out to morphologically- and molecularly-characterize O. ovis larvae collected from sheep in a slaughterhouse in Al-Qadisiyah province, Iraq. The study depended on collecting 20 larvae (at different stages) from 20 sheep from 15 October till 17 December 2020. The morphological examination was done using a stereomicroscope and relying on larval characteristic features, including the posterior end, spiracles, and cephalopharyngeal skeleton. The molecular characterization was performed utilizing polymerase chain reaction (PCR) and partial gene sequencing (PGS) methods of the cytochrome c oxidase subunit I (cox1) gene at 700-bp and 300-bp regions. Morphologically, the first-stage larvae (L1) showed characteristic mouth hooks, while the second-stage larvae (L2) revealed clear terminal stigmas. For the third-stage larvae (L3), the color of body segments and their spines' were the most important features for this larval stage. The PCR showed amplification at both regions 700bp and 300bp, in 8 and 7 isolates, respectively. The PGS revealed 15 different local isolates in genetic level aligned with isolates from Kyrgyzstan, Italy, Spain, and Turkey. This study shows the important strain differences of O. ovis that infect the local sheep in Al-Qadisiyah province, Iraq.

Rearing and measurements of Oestrus ovis larvae and pupae (Diptera: Oestridae) from slaughtered sheep heads in Mosul abattoir -Iraq

A.B.J. Alani; E.R. Al- kennany; N.H. Al-ubeidi

Iraqi Journal of Veterinary Sciences, 2018, Volume 32, Issue 1, Pages 21-25
DOI: 10.33899/ijvs.2018.153789

Oestrus ovis larvae 142 were collected from the 133 heads of sheep slaughtered at the Mosul abattoir in Nineveh governorate during March-May 2014. In This study, the weight and dimensions Oestrus ovis larvae and pupae were measured and there was a significant difference between larvae of Oestrus ovis. Forty five of the third larval stage were rearing and them pupated until emergence of the adult stage. Sixteen larvae were emerged to adult (35.6%). (4.4%) larvae did not pupariation and 60% were not reached to adult. The puparation period taking (24-30 hours) and the pupal stage taking (23-28) days the average longevity of adult flies was 10 days. This study is regarded as the first one showing that all flies were similar in their external shape and so all were belonging to Oestrus ovis causing myiasis in sheep.