Pests or beneficial insects? Fight or Attract?

the essentials in brief

• Fire beetles should not be fought because they do no harm
• Fire beetles are beneficial insects: They prevent the spread of fungus and eat the larvae of pests
• Adult fire beetles only live briefly, the larvae overwinter and develop into beetles in the next spring

Is it necessary to combat it?

Killing fire beetles only makes sense in the event of specific damage. If your plants are damaged, the cause should be addressed. Since the adult beetles do not feed on living tissue, but only consume plant juices and nectar, there is no need to worry about your garden. It is therefore not necessary to get rid of the insects. This also applies to the larvae, because they only feed on the wood-dwelling insects and fungi. If you want to get rid of fire beetles, you are jeopardizing the natural balance.

Fire beetles are completely harmless and anything but harmful. On the contrary: they even help to keep the ecosystem in balance.

Be careful when using chemical agents

There are numerous home remedies that can be used for pesky insects. In addition to deterring substances such as coffee grounds, there are also more aggressive methods that kill the pests. However, most of the remedies do not work selectively. They kill all insects that come into contact with the substances. When you control aphids, fire beetles can also be harmed. Therefore, pay attention to which substances you use in the garden and whether they can also damage beneficial living beings.

How home remedies work:

• oil: prevents oxygen uptake
• soap: causes dehydration
• Fragrances: confuse or deter

Toxic and dangerous?

All three types of fire beetles that you can find in nature are completely harmless. The beetles are unable to damage human skin because they have no mouthparts to bite or sting. The larvae do not pose a threat to humans either. Only conspecifics have to be careful if the insects are prone to cannibalism.

Beware of fire-red insects?

There are numerous species in the animal kingdom that warn potential predators with their conspicuous colors. Bright red shades often indicate that the animal is poisonous. But there are also insects that have only adopted the outward appearance of dangerous species. Fire beetles are one of them. Their color is said to have a deterrent effect, although the insects do not produce any toxic substances. They are also not toxic to children or responsible for a sudden rash.

In the house

If a fire beetle accidentally gets lost in the apartment, don't panic. The animals are probably more scared than you are. Make sure that the insect returns to its natural habitat quickly. Use a glass that you put over the animal. Then you can slide a sheet of paper under the glass and thus transport the beetle into the glass. Put it out at the edge of the forest or on dead wood.

Harmful or useful?

Fire beetles do not become a nuisance. They do not spread en masse, nor can they be called pests. Adult beetles are not dangerous for the plants as they do not feed on the plant tissue and therefore do not leave any damage.

They only feed on sap that is secreted by flowers or that come out through open wounds on trees. No living trees are sought to lay eggs. The larvae develop in dead wood and do not feed on plant tissue either.

Prevent fungus from spreading

The insects are often found near plants that have been infected by aphids. As a result, they often give the impression of a plant pest, but they are not after the plant. Much more attractive are the sweet secretions of aphids, which are eaten by fire beetles.

Fire beetles protect your plants. Honeydew often offers good living conditions for sooty mildew fungi. If the plant is completely covered by the excretions of the plant sap sucking lice, their photosynthetic performance can be extremely limited. Fire beetles free the plants and ensure that no fungi can settle on the sticky mass.

Eliminate unwanted insects

The larvae are predatory and hunt other insect larvae. These are killed and sucked out. Although cannibalism can also occur, the larvae primarily target alien larvae. It is not uncommon for bark beetle larvae to appear on their menu. That is why fire beetles are one of the most valuable beneficial insects when it comes to fighting bark beetles.

This is why bark beetles are dangerous:

• drill tunnels in the bark of healthy trees
• lay eggs in the breeding tunnels
• can multiply en masse during long periods of heat and drought
• cause pure spruce stands to die off

What do fire beetles eat?

Adult fire beetles rarely eat. They feed exclusively on sweet juices such as flower nectar or tree sap. The honeydew from aphids is a particularly tasty addition to the menu.

Larvae eat various fungi that grow in the dead wood. They also feed on other insect larvae that they find under the bark and in dead wood. When there is a shortage of food, cannibalism can be observed. However, this is only the exception and occurs more often when the conditions are no longer optimal. Time and again, drought leads to the fact that more developed larvae eat younger generations.

The fire beetle in portrait

Fire-colored beetles are a family of insects whose scientific name is Pyrochroidae. They belong to the order of the beetles and are sometimes referred to as cardinals. The family includes around 140 species worldwide, eight of which are native to Europe. Only three species live in Central Europe. The flight time of the species occurring in Central Europe is limited to a short period between May and June. When a thunderstorm approaches, the beetles seek shelter in the vegetation.

Fire beetles prefer to fly in this weather:

• Calm
• high relative humidity
• Temperatures over 20 degrees Celsius

general characteristics

Cardinals grow to be between three and 20 millimeters long, with their bodies appearing flat and elongated. The top is finely haired, which is only visible under the microscope. Almost all species are red to brick-red in color.

The large and flat head, which is constricted at the transition to the neck and merges into a narrow pronotum, is striking. In contrast to other beetles, the temples of the fire beetles are clearly visible. The actual wings are protected by cover wings, which are widened to the rear and have longitudinal grooves in some species.

pairing

The insects multiply in spring. Some fire beetles use the chemical compound cantharidin to find a suitable mate. This natural substance is said to have an aphrodisiac effect, because the males are said to be more attractive to females due to a particularly high content of cantharidin. However, fire beetles cannot produce this lure pheromone themselves. They take up the natural substance when larvae suck up dead insects. However, the smell has a deterrent effect on many other insects.

development

The females usually lay their eggs under the bark of dead deciduous trees. Here the larva hatches under sheltered conditions in self-dug or unfamiliar passages. She has a strongly flattened body and shows predominantly predatory behavior.

Insects and their larvae are part of the menu of fire beetle larvae. But they also feed on fungi that have settled in the dead wood. The larvae pupate between the wood and the bark, only to crawl to the surface as adult beetles after two to three years. Under favorable conditions, adult beetles develop after a year.

Where do fire beetles live?

Fire beetles inhabit forest edges and forests in which deciduous trees dominate. The more natural the forest, the better the insects can spread. They are dependent on dead wood, which hardly exists in wooded forests. Fire beetles do not find suitable living conditions in monocultures, which mainly consist of conifers.

Your larvae need lignified material, which is already in an advanced stage of rotting. This offers protection and a high level of humidity, which the larvae depend on. If the wood is uncovered, the larvae escape into moister cracks in the wood or into deeper layers of bark.

Herb-rich undergrowth with flowering plants is also important, because adult fire beetles get their food from the flowers. Herbaceous plants that produce nectar are important here. Fire beetles do not hang around flowers that have no nectar to offer.

These trees are preferred:

• Oak
• Linden tree
• birch

Overwinter

Adult fire beetles do not hibernate. Their sole reason for being is mating, which takes place shortly after hatching between May and June. As soon as this is completed and the eggs have been laid, the animals die. Only their larvae overwinter under the bark of dead trees. How often the larvae hibernate depends on factors such as weather and food availability. Usually one or two winters pass before they pupate.

Whether the larvae are active in winter presumably depends on the conditions. The more protected and isolated the habitat, the more active the larvae are. The temperature at which the insect larvae die is not known, at least for the native species.

Digression

Dendroides canadensis

species

The species-rich family contains 21 genera. There are three species native to Central Europe that inhabit very similar habitats. It is not uncommon for larvae of different fire beetle species to live together under the bark of dead trees. They look very similar and can easily be confused with one another.

Scarlet Fire Beetle (Pyrochroa coccinea)

This species becomes between 13 and 18 millimeters long. The body is flat and wide. The wing and pronotum are bathed in strong red tones, while the rest of the body glows in a deep black. If you take a closer look, you can see a brown-red sheen on the forehead. The claw on the legs is also noticeable, because it is reddish-brown in color on the scarlet fire beetle.

Their flight time extends from May to June. This species is comparatively common and is also found in the southern and central parts of Scandinavia. It inhabits forest edges and clearings and is often found on dead wood and on blossoms.

Red-headed fire beetle (Pyrochroa serraticornis)

This beetle is slightly smaller than the scarlet fire beetle because it is only ten to 14 millimeters long. There are similarities in the coloration of the pronotum and the wing, because these are also colored red in Pyrochroa serraticornis. The most important difference is the red head color that gave this species its name.

Good to know:

• occurs in temperate regions of Europe
• predominantly in Central Europe
• lives on the edge of the forest and in clearings
• significantly rarer than the scarlet fire beetle

Orange fire beetle (Schizotus pectinicornis)

This beetle is the smallest of all fire beetles native to Europe, because it reaches a maximum body length of nine millimeters. The pronotum is slightly rounded on the sides and has a black spot. The upper wings have flat longitudinal ribs, which, however, are very weak. Both parts of the body are colored orange-red while the rest of the body is black. Occasionally this species can also be observed under the bark of spruce and pine trees.

Distribution:

• large parts of Europe up to the Arctic Circle
• predominantly deciduous forests
• especially in the foothills and in the mountains

Identify larvae

All three native species lay their eggs on dead wood. The larvae live under the bark and look very similar. Some body features are used to identify the species. The distribution also gives an indication of the species, even if the areas often overlap.

Confusion with other species

Fire beetles are often mistaken for similar looking species. Various features help to distinguish the animals from one another. This can also be done with bare eye will.

The types differ in this:

• Coloring of the wing-coverts
• body shape
• piercing-sucking mouthparts in Schnabelkerfen
• chewing mouthparts in beetles

Common fire bug

This species does not belong to the group of beetles. Fire bugs are an independent family that belong to the order of the Schnabelkerfen. Thus the insects are only distantly related to the fire beetles, which fall into the order of the beetles. The German trivial names are incorrectly used synonymously. Fire bugs are popularly referred to as fire beetles and vice versa.

However, the respective types can be very easily distinguished if you take a closer look. Fire bugs have a typical color pattern. Their elytra are colored red with black dots and triangles. Fire bugs are often found in large clusters and colonize open habitats such as cemeteries with deciduous trees.

Lily Chicken

This plant pest belongs to the leaf beetle family and is characterized by a sealing lacquer-red color on the pronotum and elytra. As a result, the lily chicken can easily be mistaken for fire beetles, but these insects only reach a body length of between six and eight millimeters.

There are other differences in lifestyle and diet. These fake fire bugs are up Lilies specialized. They lay their eggs on the underside of the leaves. The hatched larvae feed on the leaves like adult insects. They pupate in the earth.

Fire beetle in the garden

Since fire beetles do not cause any damage and their larvae even prove to be useful, it makes sense to settle the animals in your own garden. To do this, you have to design the living conditions in such a way that the beetles find enough food, places to retreat and places to lay eggs.

If you want to remodel your garden accordingly, you should orientate yourself on the way of life of the insects. The more natural the living space, the more attractive the garden appears to the fire beetles. You don't need a lot of space to create an oasis. You can also create new living spaces with small changes on the balcony.

Deadwood

Dead wood is a valuable habitat for numerous organisms. In Central Europe, more than 1,300 different insect species live on old and dead wood. This includes the larvae of the fire beetle. This diversity of insects attracts numerous songbirds and woodpeckers that feed on the insects. You can use old wood to create such a species-rich oasis in the garden. Fallen trees, dead roots or fallen branches are ideal as dead wood.

Stack the material in a garden corner or distribute it evenly over the surface. Fire beetle larvae feel comfortable in particularly thick trunks that are already in an advanced stage of decomposition. There is high humidity in the rotten wood, which the larvae depend on.

This is what the ideal pile of dead wood looks like:

• Dig a pit
• Pile up large pieces of branches, tree slices and roots
• Fill the leaves and sticks in the spaces between them

Flower strips

In order to offer the beetles an abundant supply of food, you should create flower strips rich in species. You can work these into a lawn. The flowers are preferred when they are not exposed to the blazing sun. Fire beetles like partially shaded conditions that are similar to the ratios of forest edges and clearings.

frequently asked Questions

What is the difference between fire beetles and fire bugs?

Fire bugs belong to a different order than fire beetles. They differ in their coloring. While the common Fire bug is colored red and has black markings, the three native species of fire beetles are solid red. Bugs have proboscis-like mouthparts that they use to suckle. Fire beetles, on the other hand, have chewing mouthparts.

Why do fire beetles combine?

Many insects combine to mate. In fire beetles, however, no connections can be observed that last for several hours or even days. What is meant here is the common fire bug, which is incorrectly referred to as a fire beetle. Males and females of these insects can often be seen in a position in which the two hind ends are firmly connected. Because the males want to prevent females from mating with competitors, the connection is sometimes maintained for several days.

Where do fire beetles come from?

The conspicuous insects live in the shelter of trees and bushes in the herbaceous lower layer. They prefer light conditions and often sit on flowers because they feed on the nectar. They lay their eggs in dead wood. This is where the larvae hatch and retreat into the damp cracks in the wood and hunt other insect larvae.

It is a mistake that the animals depend on burned wood. However, there is a species known as the fire beetle that takes advantage of forest fires. The Australian fire jewel beetle is behind this species.

Way of life of the Australian fire beetle:

• Laying eggs on smoldering and smoking trunks
• spoon-shaped larvae eat their way into the wood
• Resin from living trees endangers the development of the larvae

Where did the name come from?

Many fire beetles are showy in color, ranging from scarlet to black. The bright red has been associated with fire in the past, which is how the beetles got their name. The scientific name is made up of the Greek terms “pyros” for fire and “chroma” for color. The German name is a translation of this designation. Fire beetles are also mistakenly called fire bugs, but they belong to a different family.

What do fire beetles need to survive?

The insects are among those living things that depend on dead wood. Their larvae can only develop under the protection of old wood, which is in an advanced stage of decomposition. Inside there is a humid environment, which offers optimal growth conditions for mushrooms. These are vital for the larvae, as they are eaten with preference along with other insect larvae.

What are fire beetles good for?

Fire beetles prove to be useful creatures in pest control. Their larvae hunt other insect larvae that are in the dead wood. The larvae of the dreaded bark beetle are also on their menu. Adult fire beetles feed mainly on sweet plant juices. But even the sticky secretions of aphids are not spurned. In this way, fire beetles ensure that fungi do not spread on the infected plant.