Areas Of Tasmania Research Articles

OBSERVATIONS ON THE PASTURE BEETLE, SAULOSTOMUS VILLOSUS WATERHOUSE (SCARABAEIDAE: RUTELINAE)

Saulostomus villosus inhabits parts of south-eastern Australia, including Tasmania. In Tasmania adults were taken at lights in December, January and February. Eggs were laid in the insectary in December and they emerged one month later. First and second instar larvae were field collected from February until October and third instar larvae were collected throughout the year. Pupae were collected in November. It appears the species has a life-cycle of at least 2 years duration. S. villosus occurs in semi-improved and improved pastures on sandy to clay loam soils in regions with an annual average rainfall of 600 to 1,200 mm. Dense larval populations have caused minor pasture damage in some areas of Tasmania. Characters of use in distinguishing the larval stage from those of other scarabaeids are described.

THE BIOLOGY OF FRAUS SIMULANS WALKER (LEPIDOPTERA: HEPIALIDAE)

Fraus simulans Walker a univoltine hepialid, is a native of south-eastern Australia and inhabits most pastoral areas of Tasmania. The adults are crepuscular and fly in late March and early April. The females mate before flying and each lays about 400 eggs. Laboratory studies indicated that the egg stage which lasts about 35 days at 15dC is capable of with-standing the normal range of temperature and moisture experienced in the field in Tasmania in the autumn. The larvae inhabit vertical tunnel in the soil and emerge at night to feed on the foliage of herbaceous plants, particularly grasses. Food consumption appears to be greatest during the period September to December. Pupae are present in February and March. Parasites and predators appear to be few and it is concluded that climatic factors may have a major influence in determining the abundance of F. simulans.