Spined Soldier Bug Identification Guide
Podisus maculiventris
The spined soldier bug is a predatory insect in the stink bug family. Learn how to identify this species and tell it apart from pest stink bugs that invade homes.
Taxonomy
Spined Soldier Bug Coloration
Common color patterns to help identify spined soldier bug
Spined Soldier Bug
Seasonal Activity
When spined soldier bug are most active throughout the year
Where Spined Soldier Bug Are Found
Hover over states to see their names. Green regions indicate where spined soldier bug have been reported.
Spined Soldier Bug Identification Guide
Physical Characteristics
The spined soldier bug (Podisus maculiventris) is the most common predatory stink bug in North America. Adults are 8 to 13 mm long, or about the size of a dime. They have the shield-shaped body found in all stink bugs. Their color ranges from pale brown to tan with mottled gray and brown markings.
The key feature that sets spined soldier bugs apart from pest stink bugs is a pair of sharp spines on the “shoulders.” These are the corners just behind the head. The spines are easy to spot and give the bug its common name. Pest stink bugs like the brown marmorated stink bug have rounded shoulders with no spines.
You can also look at the beak. Spined soldier bugs have a thick beak that is at least twice as thick as their antennae. This heavy beak lets them catch and eat other insects. Plant-feeding stink bugs have much thinner beaks.
Adult spined soldier bugs also have a dark line on the tip of each forewing. This marking plus the shoulder spines makes them easy to tell apart from pest species.
Life Stages
Spined soldier bugs go through five nymph stages before they become adults. The young bugs look very different from adults:
- 1st instar: Very small (about 1.4 mm), with a black head and a reddish belly with black markings
- 2nd instar: Larger than before, starts hunting prey
- 3rd instar: Shows black, orange, and white markings on the reddish belly
- 4th instar: Similar coloring with small wing pads starting to form
- 5th instar: Wing pads are larger, body turns mottled brown, belly markings change to white or tan with black
Eggs are barrel-shaped and about 1 mm wide. They have small spines around the top. Females lay eggs in clusters of 17 to 70 on leaves and stems.
Common Species
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Spined Soldier Bug (Podisus maculiventris): The most common predatory stink bug in North America. Found from Mexico north into Canada.
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Two-spotted Stink Bug (Perillus bioculatus): A predatory species with two dark spots on its back. Known for eating Colorado potato beetles.
Spined Soldier Bug Behavior and Biology
Predatory Lifestyle
Spined soldier bugs hunt and eat other insects. Studies have found them eating over 100 species of prey, including:
- Caterpillars like armyworms and cabbageworms
- Beetle larvae
- Aphids
- Sawfly larvae
- Other stink bugs and true bugs
- Insect eggs
When hunting, spined soldier bugs push their mouthparts forward to catch prey. Plant-feeding stink bugs point their mouthparts down. Spined soldier bugs grab prey with their front legs, pierce it with their beak, and drink the body fluids.
Both young and adult spined soldier bugs are active hunters. Young bugs start hunting soon after their first molt. One spined soldier bug can eat dozens of insects in its lifetime.
Lifecycle and Reproduction
It takes 27 to 38 days for an egg to become an adult. The time depends on temperature and daylight. Eggs hatch in five to nine days. Adults can live one to four months during warm weather.
In warm areas like Florida, spined soldier bugs stay active all year. In cold areas, they have two to three groups of young per year. The last group of adults goes dormant and spends winter hiding from October to April.
Overwintering Behavior
Unlike pest stink bugs that invade homes by the thousands each fall, spined soldier bugs rarely come indoors. They spend winter in places like:
- Under loose bark on trees
- In leaf litter on the ground
- In thick plants
- Under logs and rocks
This is a big difference for homeowners. If you see stink bugs on your home in fall, they are most likely pest species, not spined soldier bugs.
Spined Soldier Bug vs. Pest Stink Bugs
Many homeowners mix up spined soldier bugs with pest stink bugs. Here are the key differences:
| Feature | Spined Soldier Bug | Pest Stink Bug |
|---|---|---|
| Shoulders | Sharp, pointed spines | Rounded, no spines |
| Beak thickness | Thick (2x antenna width) | Thin (same as antenna) |
| Diet | Hunts other insects | Feeds on plants |
| Plant damage | None | Causes damage |
| Home invasion | Rare | Very common in fall |
| Odor when crushed | Mild | Strong, bad smell |
Role in Gardens and Farms
Spined soldier bugs eat many crop and garden pests. In farm settings, they help reduce pest numbers without sprays.
Studies show:
- In potato fields, spined soldier bugs cut Colorado potato beetle numbers by up to 50%
- Some greenhouses buy and release spined soldier bugs to control caterpillars
- Pheromone lures can attract spined soldier bugs to crops that need pest control
When to Contact a Professional
Spined soldier bugs do not cause problems in homes. They rarely come indoors. But if you see large numbers of stink bugs entering your home, you likely have pest species that need attention.
Signs you may need help include:
- Large groups of stink bugs on sunny walls in fall
- Stink bugs getting inside your home near windows
- Bad smell from crushed or disturbed bugs
- Damage to garden plants from stink bug feeding
A pest control expert can tell you whether you have pest stink bugs or spined soldier bugs. For pest stink bugs, control typically includes:
- Exterior barrier treatments around entry points
- Sealing cracks and gaps around windows and doors
- Preventive sprays before fall invasion season
References
Other Stink Bugs
Explore other species in the stink bugs family
Commonly Confused With
Spined Soldier Bug are often mistaken for these similar pests
Where Spined Soldier Bug Are Found
Hover over states to see their names. Green regions indicate where spined soldier bug have been reported.
Common Questions about Spined Soldier Bug
Are spined soldier bugs harmful to humans?
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No, spined soldier bugs do not harm humans. They do not bite or sting people. Like other stink bugs, they can release a mild odor when disturbed.
What do spined soldier bugs eat?
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Spined soldier bugs are predators that feed on over 100 species of pest insects. They primarily eat caterpillars, beetle larvae, aphids, cabbage loopers, and Mexican bean beetles. They use their sharp beak-like mouthparts to pierce prey and consume their body fluids.
How can I tell a spined soldier bug from a pest stink bug?
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Look at the shoulders behind the head. Spined soldier bugs have sharp, pointed spines on each shoulder, while pest stink bugs like the brown marmorated stink bug have rounded shoulders. Spined soldier bugs also have a thicker beak designed for hunting insects rather than feeding on plants.
Do spined soldier bugs damage plants?
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No, spined soldier bugs do not feed on plants. They are strictly predatory and only hunt other insects. When prey is scarce, they may occasionally feed on plant juices, but this does not cause visible plant damage.
Why are spined soldier bugs in my garden?
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Spined soldier bugs go where they can find prey. If you have caterpillars, beetles, or aphids in your garden, spined soldier bugs may arrive to hunt them.
Do spined soldier bugs enter homes like stink bugs?
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Unlike pest stink bugs that swarm into houses each fall, spined soldier bugs rarely enter homes. They prefer to spend winter outdoors under leaf litter, bark, and in other sheltered natural areas.
How can I tell if I have spined soldier bugs or pest stink bugs?
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Check the shoulders behind the head. Spined soldier bugs have sharp pointed spines, while pest stink bugs have rounded shoulders. Also, pest stink bugs gather on homes in fall to get inside, while spined soldier bugs stay outdoors.
With five years of hands-on experience in the pest control industry, George Schulz is a registered technician with the Virginia Pest Management Association and a proud third-generation professional in a family business that's been protecting homes for over 57 years. He manages and trains a team of service pros while also leading internal research efforts—recently spearheading a deep-dive review of thousands of documents on pest control materials to hand-pick the most kid and pet friendly, most effective solutions tailored specifically for homes in the DC metro area.