There are many types of wasps in Arizona. Most people only think of the paper wasps. They form the “nests” that look like open umbrellas or overturned wine glasses filled with “honeycomb.” Actually, these cells contain no honey and are made of paper manufactured by the wasps from chewed up tree bark. Paper wasps are meat eaters and do not feed on pollen, though like most animals and insects, they will take advantage of high energy sugar when they find it in rotting fruit or your soda. Each colony has multiple queens, acting together to defend the nest, which can grow quite large, but the nest is only used for one season. It contains eggs and larvae, which the queens feed bits of meat and dead insects. There are several species of paper wasps. Some can be extremely aggressive while others will ignore humans if not provoked.
Hornets and Yellow Jackets are also paper wasps. They are stouter and more heavy-bodied in their proportions than paper wasps. They will form similar umbrella nests, but will stack them to form a multi-tiered nest. While paper wasps will construct their umbrellas in areas protected from rainfall, like under eaves, tables and palm fronds, hornets will build their nests in protected voids and cavities found in caves, attics and dense shrubs. Their stacked nest is enclosed in a paper envelope usually shaped like a football or globe. Yellow Jackets form similar, smaller nests, but generally select smaller voids like underground abandoned rodent burrows or dryer vents. Hornets and Yellow Jackets range from very aggressive to extremely aggressive.
Mud wasps are similar in appearance to paper wasps but have longer, thinner petioles, the narrow “wasp waist.” Mud wasps do not form nests as bees and paper wasps do. In fact, they do not form colonies. They live solitary lives, with some species forming a column of chambers in a long tube on the side of a home or other vertical surface. They may make several of these tubes, immediately adjacent to each other creating an organ pipe type of pattern. Some of the smaller species form very beautiful tiny clay pots, similar to the ones made by Native Americans. These wasps, called Potters Wasps, make their clay from wet soil usually found alongside bodies of water.
The most impressive wasps, and sometimes the most frightening, are the Cicada Killers and their giant cousins, the Tarantula Hawks. These giant wasps are usually noticed when their large shadow crosses your path. Looking up, you will see a loud, large wasp with a wingspan of up to 3 inches. Though they visit flowers for nectar, they are best known for hunting large insects and spiders. They paralyze their prey with their sting. The wasp then flies off or drags off their large victim, stashing them in a hole in the ground that the wasp created for this purpose. The paralyzed prey serves as a food source for the developing larvae. Since these wasps are solitary and do not have a nest to protect, they are non-confrontational using their sting defensively as a last resort.
Bringing firewood into your home, you may encounter another type of wasp. Wood wasps land on natural wood and sense beetle larvae feeding under the surface of the wood. Their “stinger” is a drill and ovipositor, a syringe like tube for injecting eggs under the surface and into the beetle larvae. The smallest of these wasps are so small they are mistaken for gnats, but the largest may be over an inch long. The ovipositor may be several times the length of the wasps’ body for a combined length of 3 inches or more. Firewood brought in to the home will dry out triggering the emergence of adult wasps. These large wasps begin to fly around the room, looking for a way out.
On occasion, small wasps will emerge from plants and fruit brought in to the home. These incredibly small wasps parasitize other insects that are feeding on the plants. Completely harmless to humans, these little wasps are smaller than gnats and are not usually identified as wasps. There is one species that hunts down cockroach eggs, and another that parasitizes fly pupa, the “cocoons” that adult flies emerge from.
Wasps are beneficial insects that serve to control other insect pests. Left alone, wasps typically are not aggressive, but should always be treated with respect. Your Pest Control Technician can help you decide what action to take and has the appropriate tools and safety equipment to safely manage wasps.
Call University Termite and Pest Control today to find solutions to your wasp problems. In Tucson, call 886-4146. Statewide, call 800-877-4146.