Illinois is home to a diverse array of wasps that play crucial roles in our ecosystem.
From the northern paper wasp to the intimidating cicada killer, these insects belong to several families including Vespidae, Sphecidae, and Crabronidae.
Understanding the different types of wasps in Illinois can help residents appreciate their ecological benefits while taking appropriate precautions to avoid painful stings and potential allergic reactions.
The wasp diversity in Illinois includes social species like yellow jackets and hornets, as well as numerous solitary species such as mud daubers and thread-waisted wasps.
While many people fear wasps for their venom, most species are non-aggressive unless their nests are threatened.
The Wasps of Illinois field guide identifies numerous species that help control pest populations, with many parasitoid wasps targeting specific insect pests as part of their fascinating life cycle.
Eastern Cicada Killer
The Eastern Cicada Killer (Sphecius speciosus) is one of the largest wasps found in Illinois.
Despite their intimidating size—reaching about two inches in length—these wasps are actually mild-mannered and rarely aggressive toward humans.
These wasps have a distinctive appearance with black and yellow markings on their bodies.
Their abdomen features yellow bands, while their wings have a rusty tinge, making them easy to identify among other wasp species.
Cicada killers are solitary insects, unlike social wasps such as yellowjackets.
They don’t form large colonies or defend territory in groups, which significantly reduces the risk they pose to people.
The name “cicada killer” comes from their hunting behavior.
Females capture cicadas, paralyze them with their sting, and bring them to underground nests as food for their larvae.
Nesting Habits:
- Dig burrows in well-drained soil
- Prefer sunny, bare or sparsely vegetated areas
- Create tunnels up to 24 inches long
- Each nest contains multiple cells for eggs
Though females have stingers, they rarely use them on people.
Males may seem aggressive as they defend territory, but they lack stingers entirely and cannot harm humans.
Cicada killers are beneficial insects that help control cicada populations.
They’re most active in July and August when cicadas are abundant, and their presence typically indicates a healthy ecosystem.
Bald-Faced Hornet
The bald-faced hornet (Dolichovespula maculata) is a common wasp species in Illinois.
Despite its name, it’s actually not a true hornet at all. These insects are technically a type of yellowjacket wasp, though they look quite different from their yellow relatives.
These wasps are easy to identify by their distinctive coloring. They have a mostly black body with bold white markings on their face and abdomen.
They measure between 0.5-0.8 inches in length, making them larger than many other wasps.
Bald-faced hornets build large, football-shaped paper nests that hang from tree branches or building eaves.
These impressive structures can grow to 14 inches in diameter and house between 400-700 workers at their peak.
Behavior and Diet:
- Primarily feed on insects and nectar
- Aggressively defend their nests when threatened
- Can sting multiple times, unlike honeybees
The sting of a bald-faced hornet is quite painful. These wasps can be dangerous to those with allergies, and their defensive nature means they may attack in groups if their nest is disturbed.
Nests are typically abandoned in late fall when temperatures drop.
Only young queens survive the winter by finding shelter in rotting logs or other protected areas. They emerge in spring to start new colonies.
While they may seem intimidating, bald-faced hornets provide valuable pest control by hunting flies, caterpillars, and other insects. It’s best to appreciate them from a safe distance.
Paper Wasp
Paper wasps (Polistes spp.) are common insects found throughout Illinois.
The Northern paper wasp (Polistes fuscatus) is one of the most recognizable species in the state.
These wasps have a distinctive appearance with red eyes, dark wings, and red-yellow striped abdomens.
Paper wasps get their name from the paper-like material they use to build their nests.
They create these nests by chewing wood fibers and mixing them with saliva.
The result is a horizontal comb of paper cells that often hangs from overhangs or near outdoor lights.
Several paper wasp species call Illinois home, including:
- Northern paper wasp (Polistes fuscatus)
- Metric paper wasp (Polistes metricus)
- European paper wasp (Polistes dominula)
The European paper wasp is a newer arrival to Illinois. This species was first identified in Urbana in central Illinois and has been present in northern Illinois for several years.
Paper wasps are generally less aggressive than some other wasp species. However, they will defend their nests if threatened.
Their sting can be painful and may cause allergic reactions in some people.
Despite their intimidating appearance, paper wasps play an important role in the ecosystem.
They are predators that help control pest populations by feeding on caterpillars and other insects. This makes them beneficial for gardens and agriculture.
Mud Dauber
Mud daubers (Sceliphron caementarium) are solitary wasps measuring about three-fourths of an inch to 1 inch long.
The common mud dauber (Sceliphron caementarium) has a distinctive brownish-black body with yellow markings.
These wasps also feature an elongated, very thin waist connecting the thorax to the abdomen.
Unlike social wasps that live in colonies, mud daubers live alone.
They build characteristic mud nests that look like organ pipes or clumps of dirt attached to walls, ceilings, or other sheltered areas.
These artistic structures are made of mud collected from puddles and wet areas.
Mud daubers are generally non-aggressive and rarely sting humans.
They prefer to save their venom for their prey – spiders. Yellow-legged mud daubers specifically prey on spiders, which they paralyze with their sting and store in their mud nests as food for their larvae.
The life cycle of mud daubers includes:
- Egg-laying in mud nests
- Larvae feeding on paralyzed spiders
- Pupation inside the mud chamber
- Adults emerging to start the cycle again
Birds are natural predators of mud daubers, as they typically feed on solitary wasps while avoiding social wasp species that might attack as a group.
Despite their somewhat intimidating appearance, mud daubers are beneficial insects that help control spider populations.
Their presence around homes actually indicates fewer spiders in the area.
Great Golden Digger Wasp
The Great Golden Digger Wasp (Sphex ichneumoneus) is a striking insect found throughout Illinois.
It features a distinctive appearance with a deep black head and thorax covered in dense, velvety golden hairs.
This solitary wasp species belongs to the taxonomic Kingdom Animalia and can be found statewide in Illinois.
Unlike social wasps that live in colonies, these digger wasps lead independent lives.
Despite their intimidating appearance, Great Golden Digger Wasps are generally non-aggressive toward humans.
They’re currently being studied by scientists for their behavioral responses, offering valuable insights into insect behavior.
These wasps earn their “digger” name from their nesting habits.
Females excavate burrows in soil where they place paralyzed prey for their developing young.
This behavior helps control populations of certain insects.
Important to note: Great Golden Digger Wasps serve as pollinators in Illinois ecosystems.
While collecting nectar, they transfer pollen between flowers, supporting plant reproduction.
When encountering these wasps, it’s best to observe from a distance.
Though not typically aggressive, they can sting if handled or if their nest is disturbed.
Their distinctive coloration helps distinguish them from other common Illinois wasps like the Great Black Digger Wasp and the Katydid Wasp.
Blue-Winged Wasp
The Blue-winged Scoliid Wasp (Scolia dubia) is a distinctive insect found in Illinois.
It has a black and hairy head, thorax, and upper abdomen, making it easily recognizable among other wasps.
This beneficial wasp measures about 3/4 to 1 inch long with metallic blue-black wings that shimmer in sunlight.
The lower portion of its abdomen displays bright reddish-orange bands, creating a striking contrast against its dark body.
Habitat and Behavior:
- Found in gardens, meadows, and grassy areas
- Active during late summer and early fall
- Attracted to flowering plants for nectar
- Non-aggressive toward humans
Unlike yellowjackets or hornets, the Blue-winged Wasp is solitary, meaning it doesn’t live in colonies.
Each female builds her own nest and provisions it independently.
These wasps serve an important ecological role as natural pest controllers.
They specifically target beetle grubs, including the destructive Japanese beetle larvae that damage lawns and gardens.
The female Blue-winged Wasp hunts by digging into soil to locate grubs.
Once found, she paralyzes the grub with her sting and lays an egg on it.
When the wasp larva hatches, it feeds on the living but paralyzed grub.
Gardeners should welcome these natural predators in their yards.
Despite their intimidating appearance, they rarely sting humans unless handled or threatened directly.
To attract these beneficial insects, plant diverse flowering plants and avoid using broad-spectrum insecticides that kill indiscriminately.
Braconid Wasp
Braconid Wasps (Braconidae Family) are small but beneficial insects found throughout Illinois.
They belong to the second-largest family in the order Hymenoptera, after their close relatives, the Ichneumonidae.
These tiny wasps might be mistaken for flies if not for their distinctive coloration and the female’s long ovipositor.
The ovipositor is a tube-like organ that females use to lay eggs inside or on host insects.
Braconids serve a vital ecological role as parasitoid wasps. They target garden pests and use them as living food sources for their developing offspring.
This natural pest control helps maintain balance in gardens, farms, and wild areas across Illinois.
Many species in the Braconidae family are specialized in the types of hosts they attack.
Some target specific caterpillars, while others focus on aphids or beetle larvae.
The life cycle of these wasps is fascinating and somewhat gruesome.
The female wasp injects her eggs into a living host, and when the larvae hatch, they consume the host from the inside out.
One notable example is Meteorus, a genus of braconid wasps found in Illinois.
These mini-wasps help protect plants in gardens and agricultural fields by controlling pest populations naturally.
Despite their important ecological role, braconids often go unnoticed due to their small size.
They typically measure only a few millimeters in length and don’t sting humans.
Gardeners and farmers should welcome these beneficial insects as they provide free, environmentally friendly pest management services without the need for chemical pesticides.
Ichneumon Wasp
Ichneumon wasps (Ichneumonidae Family) are fascinating parasitic insects commonly found in Illinois.
These wasps belong to the Hymenoptera order, which includes ants, bees, and other wasps.
What makes ichneumon wasps unique is their parasitic lifestyle.
Females use their long ovipositors to lay eggs inside other insects, such as caterpillars or larvae.
The young wasps then develop by feeding on their host from the inside out.
These wasps have a distinctive appearance with a narrow “wasp waist” but differ from stinging wasps as their ovipositor is not modified into a stinger. Most ichneumon wasps are unable to sting humans.
Common Illinois Ichneumon Species:
- Megarhyssa atrata (Giant ichneumon wasp)
- Enicosplius purgatus
- Aritranis director
- Ceratogastra ornata
The size of ichneumon wasps varies greatly depending on the species.
While most are small, some species like the Giant ichneumon wasp can be quite impressive with their extremely long ovipositors.
Despite their somewhat intimidating appearance, ichneumon wasps are beneficial insects.
They provide natural pest control by parasitizing many insects that damage crops and gardens.
Identifying features include their long antennae, narrow bodies, and often visible ovipositors on females.
Many species display striking color patterns that vary from black to bright orange or yellow markings.
Four-Toothed Mason Wasp
The Four-toothed Mason Wasp (Monobia quadridens) is a beneficial insect commonly found in Illinois gardens.
It has a distinctive appearance with a shiny, black body featuring ivory markings on each shoulder, a thin ivory band before the waist, and another ivory band on the abdomen.
This wasp is often mistaken for the Bald-faced Hornet due to their similar appearance. However, they have different behaviors and nesting habits.
Unlike social wasps that live in colonies, the Four-toothed Mason Wasp is solitary.
Each female builds her own nest without help from other wasps.
Diet and Behavior:
- Adults drink flower nectar as their primary food source
- Females hunt caterpillars to feed their young
- They are considered beneficial for garden pest control
Mason wasps get their name from their nesting habits. They build nests using mud or clay in hollow stems, abandoned beetle burrows, or man-made structures.
The female wasp provisions each nest cell with paralyzed caterpillars before laying an egg.
This provides food for the developing larva after it hatches.
Despite their intimidating appearance, Four-toothed Mason Wasps are generally non-aggressive toward humans.
They typically only sting when handled or directly threatened.
Gardeners in Illinois should consider these wasps as allies in controlling caterpillar populations that might otherwise damage plants.
Yellowjacket
The Eastern yellowjacket (Vespula maculifrons) is one of the most common wasp species found in Illinois.
These small, aggressive insects are known for their distinctive yellow and black striped bodies.
Yellowjackets build nests that can house hundreds or even thousands of workers.
While most species create subterranean nests, some may build in wall voids, attics, or hollow trees.
These wasps are notorious for their painful stings and aggressive behavior, especially when their nest is threatened.
In fact, more people are stung by yellowjackets than any other type of wasp or bee in Illinois.
Diet and Behavior:
- Young larvae feed on protein (meat, insects)
- Adults consume sweet liquids and nectar
- Often attracted to picnics and outdoor gatherings
- Notoriously aggressive defenders of their nests
The Eastern yellowjacket is a familiar picnic pest in Illinois, often disrupting outdoor meals while searching for food.
They become particularly aggressive in late summer and early fall.
Despite their fearsome reputation, yellowjackets play an important ecological role.
Adult yellowjackets are pollinators, while their predatory habits help control populations of flies, caterpillars, and other insects.
If encountering a yellowjacket nest, it’s best to keep a safe distance and contact a professional pest control service for removal, especially for people with allergies to insect stings.
