Fire Ants

Introduction

There are also ants which inject venom into human beings in much the same way as bees wasps and hornets. The most commonly reported stings are from fire ants in the US and jack jumper ants in Australia, both of which are members of the hymenoptera order of insects.

Fire Ants

Fire ants (Solenopsis invicta) are restricted primarily to the United States and whilst there are naturally occuring fire ants it seems that the ones which cause the most allergy problems are the more recently introduced species, dating from around the 1920's. These ants are slowly encroaching from their base in Texas to encompass all the southern United States - they are now encroaching northward and so are starting to become a real issue in the more densely populated areas of the US. They can now be found as far west as Nevada and as far east as Washington.

Fire Ant colonies are characterised by the mounds of soil generated above ground - a result of a network of tunnels under the ground which are used for hunting. The ants are very aggressive and will readily attack anything that disturbs their mound. After firmly grasping the skin with its jaws, the fire ant arches its back as it inserts its rear-end stinger into the flesh, injecting venom from the poison sac. It then pivots at the head and typically inflicts an average of seven to eight stings in a circular pattern. Fire ant venom is unique because of the high concentation of toxins, which are responsible for the burning pain characteristic of fire ant stings.

People are not just allergic to fire ant stings but also anaphylactic. Due to the obvious difficulties in collecting venom from fire ants (due to their size), venom immunotherapy, to be the best of my knowledge is not available for fire ants anaphylactics as a course of treatment. I understand that trials have been conducted using crushed up fire ant body parts but it would appear that this type of treatment was not particularly successful.

It would appear that the safest recourse for a fire ant allergic person is to avoid them by being very careful outside or by moving from their relatively limited geographical habitat. Otherwise protection and treatment is very similar to that recommended by for wasps and bees elsewhere in this site.

Jack Jumper and Bulldog Ants - Australia

Jumper ants are recorded throughout Australia, but usually found in Tasmania, rural Victoria, NSW, ACT and the South East of South Australia. These ants typically cause local reactions - ie swelling and heat.followed by blistering rather like the picture on the right incurred through fire ants. However in a small number of cases - around 3% research indicates - the victims do go on to have a systemic or anaphylactic reaction.

The ant is 10-12mm long, jet black, but with yellow/orange limb extremities and pincers. It has a characteristic hopping motion and is sometimes called a hopper or jumber ant.. Nests are typically a pile of finely granular gravel near the nest. This may be a mound of 20-60cm in diameter but may also be inconspicuous such as under a rock.

The Jack Jumper is carnivorous and a scavenger. It grasps its victim with its pincers and stings with a modified ovipositor, analogous to that of other hymenoptera such as honey bees and wasps.

It would appear that the safest recourse for a fire ant allergic person is to avoid them by being very careful outside or by moving from their relatively limited geographical habitat. Otherwise protection and treatment is very similar to that recommended by for wasps and bees elsewhere in this site.