Hawaii’s diverse ecosystems are home to a variety of wasp species, both native and introduced. While some wasps play a beneficial role, others, particularly non-native species, can pose concerns. Understanding the types of wasps present and their behaviors is a first step toward safe coexistence.
Wasps in Hawaii: An Overview
Hawaii’s native wasps are primarily non-social, solitary, and non-aggressive towards humans. In contrast, many commonly encountered wasps are introduced species, often through human activity.
The mild, year-round warm climate of Hawaii allows certain introduced wasp species to thrive. This can lead to larger and more persistent colonies for some social wasps. Introduced wasps establish themselves in various habitats, from urban areas to natural landscapes, and can significantly alter the local insect community.
Key Wasp Species Found in Hawaii
Among the most common and impactful wasp species in Hawaii are the Western yellowjacket, various paper wasps, and mud daubers. The Western yellowjacket (Vespula pensylvanica) is an aggressive, non-native species that arrived in Hawaii around the 1970s and has spread across most islands. These wasps are characterized by their yellow and black markings and can build large, perennial underground nests, sometimes containing hundreds of thousands of individuals. Yellowjackets are known for aggressively defending nests and can sting repeatedly.
Paper wasps, such as the common paper wasp (Polistes exclamans exclamans) and the redbrown paper wasp (Polistes olivaceus), are also prevalent. These wasps typically have reddish-brown bodies with yellow markings and construct paper-like nests that hang from a single stalk, often found under eaves, decks, or light fixtures. They vigorously defend their nests and can sting multiple times. Mud daubers, like the black and yellow mud dauber, are largely solitary wasps recognized by their slender waist and mud tube nests. Unlike yellowjackets and paper wasps, mud daubers are generally not aggressive.
Ecological Significance and Management
Wasps play varied roles within Hawaii’s ecosystems, ranging from beneficial to detrimental, depending on the species. Native wasps, such as those in the genus Sierola, are important arthropod predators and parasites, helping to regulate insect populations. Some native wasps also contribute to pollination, though this role is often overshadowed by introduced pollinators.
Invasive wasp species can have negative ecological and economic impacts. Western yellowjackets, for example, are highly predatory and can disrupt native insect populations by preying on them and competing for resources. Their large, perennial colonies exert significant predatory pressure, leading to declines in native arthropod communities. This has led to abatement measures by Hawaiian National Parks to control yellowjacket populations. Beyond ecological impact, aggressive invasive wasps can become agricultural pests and public health concerns due to their stinging. Management efforts often involve trapping and nest removal, especially in sensitive ecological areas. Biological control, such as introducing parasitic wasps for agricultural pests like the coffee berry borer, is also explored.
Safe Encounters and Prevention
Encountering wasps can be a concern, but there are practical steps to ensure safety and prevent stings. To avoid attracting wasps, keep outdoor eating areas free of food debris, dispose of food in sealed bins, and avoid leaving sugary drinks unattended. Trimming plants and trees can also help reduce potential nesting sites. Since yellowjackets often nest underground, exercise caution when walking in grassy or wooded areas.
If wasps are encountered, move slowly and calmly, avoiding sudden movements that might provoke them. Remaining still if a wasp approaches can prevent a sting, as swatting can cause them to sting and even release an alarm pheromone that attracts other wasps. If a sting occurs, wash the affected area with soap and water. Applying a cold compress can reduce pain and swelling, and over-the-counter pain relievers or antihistamines may help with discomfort and itching. Seek immediate medical attention if signs of a severe allergic reaction, such as difficulty breathing, facial or throat swelling, dizziness, or hives, occur. For large or inaccessible nests, contacting a professional pest control service in Hawaii is advisable.