Prepared Warning: Trampers Be Aware – A Comprehensive Guide on Wasp Ambushes

In the heart of Aotearoa, New Zealand, a group of adults and children experienced a harrowing encounter with wasps, the country's unwelcome inhabitants that boast the highest densities of German (and common) wasps in the world, particularly in beech forests at the top of the South Island.

The incident unfolded on a rough, tree root-covered track, where a scream echoed through the forest, followed by yelling, more screaming, and crying children. A disturbance of a wasp nest under a tree root in the middle of the track was the unseen threat that sent panic through the group.

Wasps, known for their aggressive behaviour, can sting multiple times, unlike bees who lose their stinger after the initial jab. This trait makes encounters with wasps potentially more dangerous.

Fortunately, the group was prepared with a first aid kit for wasp stings, which included self-injectable adrenaline (such as an EpiPen®), antihistamine tablets, antihistamine cream, and an inhaler that contains Ventolin. Adults quickly sprang into action, picking up children and moving them quickly away from the danger.

However, the aftermath of the encounter highlighted the importance of understanding the early signs of an anaphylactic reaction. These include feeling sick, rapid pulse, tight chest, fullness in the throat, coughing, severe swelling, rash, low blood pressure (feeling faint), vomiting, cramps, and feeling very unwell.

In an anaphylactic reaction, which can be life-threatening, it is crucial to use a Personal Locator Beacon or emergency communication device to get help, and treat with adrenalin. If stung on/in/near the mouth or lips, swelling may impact breathing. In such cases, immediately take an antihistamine tablet, apply antihistamine cream to the throat, and sip cold water.

To avoid such encounters, hikers are advised to stay away from obvious nesting sites, close off openings like holes in trees or walls that wasps could use to build nests, and cover drinks and food. Avoiding fragrant cosmetics and wearing close-fitting clothing can also reduce the risk of attracting wasps.

Localized wasp control efforts have been underway for years, led by the Department of Conservation and local or regional councils. Baiting reduces wasp numbers during the peak of the season, but does not appear to have a long-term impact, particularly in beech forests, and needs to be repeated each year.

In a bid to combat wasps, the Environmental Protection Authority | Te Mana Rauhi Taiao approved the release of two new biological controls to combat wasps in February 2021. The Tasman District Council was approved to release a beetle and hoverfly parasitoid to mitigate social wasp populations.

Biological control is not expected to be a rapid solution to control wasp populations, but a long-term, self-perpetuating control that will eventually work over a landscape scale. Fresh stock of a third biological control agent (a parasitoid wasp) will be released this summer (2022/23) at three privately owned locations in the top of the South Island, Te Tau Ihu.

Wasps are a nuisance to trampers and eat large amounts of native insects and baby birds, damaging the beech forest ecosystem. With no natural predators in New Zealand, but plenty of food and mild winters, the country unfortunately offers an ideal habitat for these pests.

To avoid disturbing wasp nests while tramping, pay close attention to where you place your feet, watch for wasps entering and exiting holes/gaps in the ground, and do a thorough assessment of the area before taking off your pack or sitting down. It is also recommended to wear long-sleeved tops and pants in areas with high wasp populations.

In the event of a wasp sting, assess and treat the sting by observing the sting location, washing the area with cold clean water, applying a cold compress, taking an antihistamine tablet, applying antihistamine cream, raising the limb or sting site, monitoring the patient's symptoms, and continuing to apply antihistamine cream and cold compression if necessary.

As we navigate the unique challenges posed by wasps in Aotearoa, it's essential to stay informed, prepared, and vigilant. By following safety guidelines and supporting ongoing wasp control efforts, we can make our tramping experiences safer and more enjoyable for all.