The ecology of lice on sheep. 2. The influence of temperature and humidity on the development and hatching of the eggs of Damalinia ovis (L)

Abstract

The temperature and humidity requirements for the development and hatching of the eggs of Damalinia ovis (L.) were determined. Morphogenesis of the eggs of D. ovia was completed only within the temperature range 30-39°C but the most favourable range was 33-39°C. When development was completed eggs hatched from 22-42.5°C. The majority of embryos within eggs incubated at 33-39°C and maintained at R.H.'s of 7-92 per cent. completed their development but those exposed to 92 per cent. R.H. failed to hatch. An exposure to 92 per cent. R.H. for only the last 24 hr of their development was sufficient to prevent hatching.