Caterpillar Hunter beetles are fascinating creatures known for their striking appearance and unique hunting habits.
One of the species, the Fiery Searcher Caterpillar Hunter (Calosoma scrutator), stands out with its deeply grooved metallic green elytra edged in lustrous reddish-orange coloration.
These meat-eating beetles play an essential role in controlling caterpillar populations, helping maintain a healthy balance in our ecosystems.
Various caterpillar species are prey for these hunters, such as the forest tent caterpillar and the eastern tent caterpillar.
Caterpillar Hunters can efficiently locate their prey and contribute to their population control, ensuring that they do not cause harm to trees and other vegetation in their natural habitats.
Understanding and appreciating the impressive Caterpillar Hunter beetle not only provides fascinating insights into the insect world.
Caterpillar Hunter Basics
Classification
Caterpillar hunters belong to the family Carabidae and are a type of ground beetle.
The ground beetles are a diverse group with over 40,000 species worldwide. Within that, the Caterpillar Hunters have 167 species.
Caterpillar hunters are well known for their beneficial role in controlling pest populations. Here are some classification details:
- Family: Carabidae
- Genus: Calosoma
Identification
Caterpillar hunters can be identified by their elongated, slightly flattened bodies and their large, powerful jaws.
They are recognizable by their large thorax, which is almost the size of their abdomens and much wider than their heads.
They have a metallic blue or green coloration, giving them a distinctive appearance.
Caterpillar hunters are well-adapted predators, feeding on caterpillars and other pests. Their habitat usually consists of gardens, fields, and agricultural areas.
Habitat and Range
United States
Caterpillar Hunters can be found throughout the United States¹.
The main species in the US, Calosoma scrutato are commonly found in forests, gardens, and fields².
Another native US species, Calosoma sayi is also found across the country.
Some key features of their habitat are:
- Presence of caterpillars as prey
- Availability of leaf litter and soil for hiding
Other Places
The Calosoma sycophanta, or forest caterpillar hunter, is native to Europe.
Moreover, eight species of Calosoma are found in the southern Levant, including Egypt, Israel, and Jordan.
Physical Characteristics
Color Variations
Caterpillar Hunters exhibit a variety of colors, including:
- Red: Some species have bright red markings or bands on their bodies.
- Green: Green is a common color in caterpillars to help them blend in with foliage.
- Brown: Many Caterpillar Hunters have a brown color, providing excellent camouflage.
Additionally, they may display gold or dotted patterns to help with camouflage or mimicry.
Size and Shape
Caterpillar Hunters vary in size and shape. Examples of different sizes include:
- Large: Some species grow up to 4 inches (10 cm) in length.
- Small: Others may be as tiny as 0.5 inches (1.3 cm) in length.
Shape variations within Caterpillar Hunters range from slender and elongated to short and stout, each adapted to their specific habitats and lifestyles.
Life Cycle
Eggs
The life cycle of a caterpillar hunter begins with the eggs.
Female caterpillar hunters lay their eggs on plants, providing a food source for the soon-to-hatch larvae.
- Eggs are small and inconspicuous
- Laid on leaves or stems of plants where caterpillars are present
Larvae
Once hatched, the caterpillar hunter larvae feed on their preferred prey: caterpillars.
Some examples of the types of caterpillars they consume include the Forest Tent Caterpillar and the Saddleback Caterpillar.
- Larvae of the spiders are active predators
- Grow and molt through several instars
- Appearance changes as they mature
Pupate
The final stage in the life cycle is pupation. Caterpillar hunters form a cocoon, typically attached to a leaf or a twig, where they will transform into their adult form.
During their life cycle, caterpillar hunters play a crucial role in controlling the populations of various caterpillar species.
By preying on these pests, they help maintain the balance of the ecosystem and contribute to the overall health of the environment.
Feeding Habits
Diet
Caterpillar Hunters are insects that primarily feed on caterpillars. They can be found on trees and among foliage, where they search for their prey.
Their food choice can significantly impact the caterpillar population, providing a form of natural pest control.
Some examples of their diet include:
- Gypsy Moths and Tent Caterpillars
- Leaf-feeding caterpillars
- Moth larvae
- Butterfly larvae
Pest Control Role
Biological Control
Caterpillar Hunters play a crucial role in biological control as they help to regulate pest populations.
They are known as voracious eaters, capable of consuming large amounts of caterpillars in a short period of time.
They feed on various caterpillar species that can harm plants and trees.
Beneficial Insects
Caterpillar Hunters are considered beneficial insects because they combat pests without harming plants.
They act as a natural alternative to chemical pesticides.
Do Caterpillar Hunters Bite or Sting?
Caterpillar Hunter beetles (Calosoma spp.) do not sting, as they do not possess a stinger. However, like many other beetles, they can bite if handled or threatened.
The bite of a Caterpillar Hunter beetle can be painful due to their strong jaws, which they use for hunting and consuming prey, but it is not dangerous or venomous to humans.
It is always advisable to handle any wildlife, including insects, with caution and respect to avoid any unnecessary stress to the animal and to prevent bites or other defensive reactions.
Caterpillar Hunter Species
Calosoma Scrutator
The Calosoma scrutator, also known as the searcher, is a large, metallic green beetle that is native to North America.
Distinguished by its bright, metallic green head and wing covers with copper or purple highlights, it primarily preys on:
- Gypsy moth caterpillars
- Tent caterpillars
- Cabbage loopers
- Cutworms
- Armyworms
- Loopers
Related Species
There are many other Calosoma species that fall within the caterpillar hunter beetle category. Some common species include:
- Calosoma sycophanta: A European species that preys on gypsy moth caterpillars.
- Calosoma frigidum: Known as the forest caterpillar hunter found in the boreal forests.
- Calosoma wilcoxi: Targets tent caterpillars across North America.
These caterpillar hunter species are vital for controlling caterpillar populations, contributing to natural pest management in various ecosystems.
Conclusion
In essence, Caterpillar Hunter beetles, particularly the Fiery Searcher Caterpillar Hunter, are invaluable assets in natural pest control, targeting harmful caterpillar species across diverse habitats.
With their distinctive appearance, adaptive features, and voracious feeding habits, they contribute significantly to maintaining ecological balance.
Recognizing the importance of these beetles in biological control offers a sustainable alternative to chemical interventions, underscoring the intricate interplay and mutual benefits within ecosystems.
Footnotes
¹ Penn State Extension
² University of Kentucky Entomology
³ Wisconsin DNR
⁴ NC State Extension Publications
12 Comments. Leave new
That is a very beautiful pic of a Calosoma sycophanta forest caterpillar hunter imported from europe,in the early 1900s to control the spread of the gpsy moth in Massachussettes.The native fiery searcher Calosoma scrutator has a red margins going around the edges of the elytra which is slightly darker matellic green to dark The previous is more of a golden green with reddish irradesence in elytra lacking the red margin on edges of elytra.Compare on bugguide.net. sincery Buggnout.
This is some kind of harpalinae. It’s hard to identify the species if you don’t have the specimen but you could try:)
I saw this bug while visiting Spokane and have wondered what it was as well. Vicious killers, I believe hunter is a good word for it. I saw two attacking a worm and threw the worm across the yard and the two bugs started hunting for it immediately. I’m usually not repelled by any type of bug but those bugs are quite disturbing.
We are on night shift doing exploration drilling and are getting swarmed by the calosoma oceanicum bug/caterpilla hunter. How do we keep them away from us? Any tricks would be greatly appriciated as there really doing our heads in.
Interestingly, we are just beginning to get reports of Calosoma adults and larvae from Los Angeles. We have no tips to repel them.
Agonum cupripenne
Thanks for the correction.
We have hundreds of these digging in our yard. I caught one to take to our neighborhood nursery so we could find out what kind it was and how to get rid of them. She has been in a glass jar for 16 days with no food or water, and is still alive and growing. They are a menace to our yard!
You still got her in that jar Dee?
Hey Jake
I am close to your over here on New Braunfels and I am experiencing the same bugs crawling everywhere. I counted over fifty just running across my driveway in about a 15 minute time frame.
They are harmless and I just leave them alone. Sweeping them out of my garage and they seem to head there whole running up the drive.
They grow up into the metallic green “TANKS” that we are all summer.
Could have used them last year as I had an invasion of caterpillars that stripped all the oaks leaves in a 10 mile radius in a matter of a few weeks.
They’ve been showing up in my house like crazy. I’ve probably seen a dozen in the past two days. I sprayed Home Defense Insect Killer around my house a week or two ago. I think that just cleared the way for them, because I never saw them before that. What can I use to get rid of them?
Yep same complaints.. i have sprayed literally everything trying to get rid of these beetles as they are inside my house in groves.. i spread diatomaceous earth around garage door and there are about 30 there dead from a week ago. Still yet they constantly will be crawling on and under my feet, up my legs constantly. Never bite just creepy and aggrivating. Just smashed 5 typing this.. pissed that i cant get rid of them. Worst part is i also have wolf spiders and since the beetle population is so abundant, these wolf spiders will get to be around 3″ leg to leg around.., huge for my standards. In ky.. but the wolf spiders will become a menace in the spring and will get a few bites from them on occasion and will walk right up to you, then run off at light speed.. one was so big when it ran under a broom i had propped up on a door, it knocked the broom over.. yes.., indeed.. these beetles have to go. Tried i think 8 different insecticides. From grub treatment to instant permethrin kill em sprays to toxic stuff that smelled like moldy garlic farts and lingered for a week.. didnt help.. maybe for a few days at most.. ive cleared the yard, keep it tidy and mowed.. dunno what to do..