Observations on the Bionomics of the Free-living First Stage Larvae of the Sheep Lungworm, Muellerius capillaris

Abstract

1. Observations on faecal pellets, herbage and soil, under natural climatic conditions, indicate that the larvae of M. capillaris survive for several months. The majority of the surviving larvae remain in the faecal pellets, and do not pass on to the herbage.2. In the laboratory, larvae survived for many weeks in dry faeces, but the longevity was less in wet faeces. They survived better at a low temperature range of 3–6°C, than at higher temperatures.3. They exhibit a considerable degree of resistance to desiccation; some survived for a maximum of fourteen days at a relative humidity of 75%.4. Bright sunlight rapidly kills off the larvae.5. They can survive at temperatures below freezing point. All of the larvae were alive after three days' continuous freezing, but none were alive after being frozen for twelve days.