Emergence season of Hypoderma lineatum warbles in southern Punjab, Pakistan

Abstract

The objective of the present study was to observe the seasonal pattern of the life cycle and the warble stage in bovines of Dera Ghazi Khan and Rajan Pur Districts of Southern-Punjab, Pakistan. The study was conducted from July 2004 to June 2005. The association was studied between various climatic changes and the fly life cycle. The larvae of warble flies were extracted from the backs of naturally infested animals and identified. The adult fly laid eggs in June, and hatched larvae penetrated the skin and followed intensive internal migration to diaphragm, esophageal wall and subcutaneous connective tissue in the month of July. At the start of August they reached the subcutaneous tissue and emergence began. In both species, the maximum warble emergence was found in mid-December and the lowest in mid-March and mid-August. It was concluded that preventive treatment should be adopted before the month of July to avoid carcass depreciation and decreased leather quality.