A postal survey of blowfly strike occurrence in two Queensland shires

Abstract

Objective: To describe the occurrence of blowfly strike in sheep flocks in two shires located in south-eastern Queensland.

Design: Postal survey of woolgrowers within Stanthorpe and Inglewood shires.

Procedure: Questionnaire posted to woolgrowers in June 1999 seeking information on the monthly occurrence of flystrike and number of sheep at risk.

Results: Incidence of body strike and breech strike between August 1998 and May 1999 was 1.1 and 0.5%, respectively. The highest incidence of body strike and breech strike was reported in lambs (6.1%) and weaner sheep (1.5%), respectively. The seasonality of the incidence of body strike was bimodal (November and February), whereas the seasonality of the incidence of breech strike was unimodal (April). Occurrence of body strike within a 3-month period in flocks located within 40 to 50 km of each other was significantly (P < 0.05) clustered.

Conclusion: Body strike appears to be more common than breech strike in the study area, mainly affects lambs and weaners and high-risk periods occur during late spring and autumn. Study results provide valuable information for planning blowfly strike control programs in the area (such as timing of management procedures, use of fly traps), and enable the economic impact of flystrike on the industry in this area to be assessed.