Eggs of chicken ascarids (Ascaridia galli and Heterakis spp.) are believed to be hardy and survive for long periods. However, this has not been evaluated quantitatively and our study therefore aimed to determine development and recovery of chicken ascarid eggs after burying in pasture soil. Unembryonated eggs were mixed with soil, placed in sealed nylon bags and buried at 7 cm depth in pasture plots April (spring, n = 72) and December 2014 (winter, n = 72). Eight randomly selected bags per season were used to estimate pre-burial egg recovery [0 week post-burial (wpb)]. Eight random bags were removed at 5, 12, 23, 38, 52, 71 wpb per season and additionally at 104 wpb for spring burial. The content of each bag was analysed for numbers and development stages of eggs. Eggs buried in spring were fully embryonated within 12 wpb. In contrast, eggs buried in winter were developing between 23 and 38 wpb, so that all viable eggs seemed to be fully developed by 38 wpb. About 90% eggs disappeared within 23 wpb (spring) and 38 wpb (winter). Small proportions (2–3%) of seemingly viable and infective eggs were still recovered up to 2 years after deposition. In conclusion, most eggs buried in temperate pasture soil seem to experience a heavy mortality within a few months after the deposition, especially during warm periods. However, a small proportion of eggs may survive and remain infective for at least 2 years.

Effects of temperature on female longevity, fecundity and fertility of the sorghum shootfly, Atherigona seccata Rondani, were investigated. The longevity, preoviposition and oviposition periods, eggs per female per day, mean eggs per female and fertility (per cent eggs hatched), for the shootflies maintained at constant temperatures of 20, 25 and 30°C and alternating temperatures of 30°C (photophase) and 20°C (scotophase) referred to as 20–30°C were determined. At lower temperature (20°C), the longevity, preoviposition and oviposition periods were prolonged considerably, while daily egg production, mean fecundity and fertility were decreased. Higher temperature (30°C) had the reverse effect on preoviposition and oviposition periods as well as daily egg production. There was a significant positive correlation between the pupal weight and the number of eggs laid by the fly at 20°C. Egg mortality increased with advance in maternal age. The rate of increase in egg mortality was faster at 30°C than at lower temperatures.