The overwintering of Heliothis armigera (Hb.) was studied

Field surveys, field cage studies, and records of light trap catches were used to follow the abundance and mortality of Heliofhis puncfiger (Wallengren) and H . armiger (Hiibner), through the autumn, winter and spring. over a 9 year period.Both the timing of spring emergence and magnitude of moth flights of H . armiger were consistent with prior observations of autumn and winter populations in the Namoi Valley. Subsequent abundance was greater in 2 seasons when wheat anthesis and spring emergence coincided. but overwintering populations declined considerably during the study period.Although H . puncfiger was not usually abundant in the area during autumn and winter, earlier and larger moth flights of that species than of H . armiger occurred in spring, leading to heavier infestation of crops and pastures. Apparent anomalies in the early spring abundance of H. puncfiger may be explained by migration from other areas, or early emergence of the non-diapausing fraction of the population.Substantial parasitism of overwintering H . armiger by Ichneumonidae and Tachinidae was recorded, while mechanical destruction of pupae during cultivation of crop residues also caused heavy mortality.

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