Nematode species | Life cycle stage | Â | Â | Â |
---|---|---|---|---|
 | Unembryonated egg | Embryonated egg | Pre-infective larvae | Infective larvae |
H. contortus | High susceptibility to cold and desiccation. High mortality at < 10°C. | Susceptible to cold and desiccation. Low hatching in the abscence of moisture and/or at < 10°C. | High susceptibility to cold and desiccation. | Optimum survival under warm and moist conditions. Poor survival in dry climates (warm or cool) and sub-freezing winter. |
T. colubriformis | Intermediate susceptibility to cold and desiccation. High mortality at < 5°C. | Intermediate susceptibility to cold. Low susceptibility to desiccation. | Susceptible to cold and desiccation. High mortality at < 5°C. | Optimum survival under warm or cool moist conditions. Poor survival over sub-freezing winters. |
Te. circumcincta | Low susceptibility to cold. Intermediate susceptibility to desiccation. High egg viability at 0-10°C. | Low susceptibility to cold and desiccation. Hatching at < 5°C. | Intermediate susceptibility to cold. Susceptible to desiccation. | Optimum survival under cool moist conditions and sub-freezing winters. Poor survival under warm, dry conditions. |