Observations on the biology and behaviour of Homoeosoma farinaria Turner (Lepidoptera:Pyralidae) on Senecio jacobaea L., in Tasmania

The blue stem borer, H. farinaria Turner has a bivoltine life cycle on ragwort, S. jacobaea L., in northern Tasmania. Development is continuous, although the insect overwinters as a quiescent larva until the onset of warmer weather in spring. Adults are active from late November and larvae from this generation quickly complete their development during summer. Second generation adults fly from mid-February until March. Surveys showed that infestations in ragwort were more common in the north than in the south of the State. Four hymenopterous parasites were identified during the study of which a braconid, Apantales sp., was predominant.