Myrmecia pilosula complex (Hymenoptera: Formicidae) (Jack Jumper ant) : distribution, colony activity and behaviour

The Jack Jumper ant (Myrmecia pilosula complex) is limited geographically to the southern parts of Australia. It has a notorious reputation with the public of Tasmania because of the high incidence of allergic reactions to its sting in this part of Australia. The ant's aggressive attack and defence behaviour increases its exposure to the human population which is exacerbated because of its habit of nesting in close proximity to urban areas. Even though this ant has a very high public profile compared to other insects, very little research has examined aspects of M pilosula that influence its exposure to the human population. In this thesis I have addressed gaps in our knowledge related to M pilosula. I have mapped their distribution, described the climatic envelope of their range and predicted their current distribution using climate parameters. On a local scale I have identified daily above ground colony activity patterns and within this, common behaviours displayed. Activity levels were not necessarily related to time of day, but did have a slight relationship with solar radiation. The exact relationship between solar radiation and colony activity has not been resolved. Other measured climatic conditions were found not to be related to ant activity. Particular behaviours displayed by M pilosula throughout a day will increase exposure to a sting event at certain times of the day. M pilosula was found to be associated with particular plant types which are used for foraging, in addition to associations between invertebrate abundance and presence of M pilosula whereby significantly more invertebrates were found on plants with M pilosula. The types of prey recovered at the nest were not reflected in arboreal samples of invertebrates associated with M pilosula. Activity at the nest surface decreases during the middle of the day. Humans are more likely to be stung at a nest in the mornings as the ants are exiting to forage, and in the afternoon when activity increases again after a lull in the middle of the day. To avoid foraging ants, humans partaldng in outdoor activities should utilise the time early in the morning before the ants begin to exit the nest and late evening when most of the ants have returned to the nest. Any outdoor activities that have to be conducted near a nest surface should be considered during the middle of the day when activity at the nest surface is at its lowest. It is likely that M pilosula forage into the night therefore the risk of sting exposure after dark should not be discounted. Due to the arboreal nature of the ant, bushwallcers should remain on pathways when possible, avoid brushing overhanging foliage and in particular, that of Eucalyptus and Acacia.