Beetles

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Beetles, Pacific Northwest

Ladybird Larvae, Beetles
Ladybird Larvae, Photo By Bud Logan

The Beetles are the most diverse order of living organisms and their numbers are extraordinary with more than 350,000 named species that represent about 40% of all insects and 30% of all animals. There are at least six times as many beetles as vertebrate species and 90 times more than the number of all mammals.

The order is divided into four suborders and about 150 families. Polyphaga is by far the largest suborder, containing 85% of the known species, including rove, scarabs, stag, metallic wood boring, click, fireflies, blister, mealworms, ladybirds, leaf, longhorn beetles, weevils and many more kinds of beetles.

Perhaps the single most important factor in the success of them is the development of the elytra or armored fore-wings that are leathery and hard, they are not used in flight but are a sheath that covers the more delicate flying wings when they are not in use. In Flight, the elytra are held perpendicular to the body and are used as airfoils.

Flat Faced Longhorn Beetles
Flat Faced Longhorn Beetle, Photo By Bud Logan

They live in almost every conceivable terrestrial and freshwater habitat and even in some marginal marine ones. Many species live in fresh water, either in the larval stage or in both larval and adult stages. Many adults have ventral patches of fine setae that trap air bubbles for use in breathing under water.

Most species of beetles are predators. They are of immense ecological and economic importance. Many are vital in the cycles of decomposition of plant and animal matter. Others are predators of insects and other invertebrates that damage crops and other plants. On the other hand, many beetles feed on the foliage and roots of plants, causing much damage to crops and they can kill huge tracts of valuable forests in a short time.

Carabid Beetle
Carabid Beetle, photo by Bud Logan
This Carabid beetle is one of the more distinctive and attractive of the ground beetles. It is common in forests, parks, and gardens in our area. They have an appetite for escargot, but will eat slugs when shelled delicacies are scarce! The narrow head is an adaptation for eating snails from the shell. This Beetle is mainly nocturnal, but after a rainfall, they become quite active, even during the daytime.

Like many ground beetles, this Beetle is flightless. In fact, the hind wings are practically nonexistent. This means that if you can make your garden Carabid friendly, they will stick around. The larvae live in the soil and prey on soil insects that can do much harm to your garden.

There are four types of Carabid Beetle species occur in the Pacific Northwest, one is limited to the Olympic mountains, the other three are common on the Coast.

Darkling Beetles
Darkling Beetle, photo by Bud Logan
The Darkling Beetle is one of the most common members of the beetle community. Mostly, they are dark colored and spend a good deal of time walking about on the ground.

These beetles feed on dead plants but also will eat fresh plant material. They prefer walking to flying. Their tracks easily can be observed in sandy areas. Darkling beetles are active both at night and during the day.

Many of these beetles have a very interesting defense mechanism. If disturbed, they assume a head down and tail up position, and if handled roughly, they emit a dark colored and foul-smelling fluid. This behavior is enough to discourage all but the most determined predators. The fluid washes off easily with water in case of contact with your hands.

Most species of Darkling Beetles are active above ground through spring, summer, and fall. With the onset of winter weather, some species seek shelter below ground in burrows of other animals and remain there until warmer weather returns in the spring.

Other species of darkling beetles do not live through the winter as adults. They lay eggs in the soil during warm weather and die with the onset of freezing. Their eggs hatch into larvae when warm weather returns.

These larvae live in the soil for up to two years before the adults emerge to eat and reproduce.

European Ground Beetle
European Ground Beetle, photo by Bud Logan
Most species of ground beetles found on Vancouver Island are dull brown or black in color, with long parallel grooves and ridges on the back of their abdomen which is actually their hardened front pair of wings. They have long legs which allow them to move quickly along the ground in search of prey.

European ground beetles are easily distinguished from the others because they are about 2.5 to 4 cm long, making them the largest ground beetles on the island and their upper thorax and elytra are metallic purple or coppery in color. The elytra each have 3 rows of dimples running along the ridges.

European Ground Beetle
European Ground Beetle, photo by Bud Logan
Like most ground beetles, European ground beetles are active at night, and during the day they can often be found resting under leaves or other objects on the ground. This species is often found in habitats associated with humans, such as gardens and near buildings. You are likely to find European ground beetles just about anywhere on Vancouver Island, in forests, fields or around your home. They are often found in large numbers in a single area.

Adult beetles spend the winter hibernating in the soil or leaf litter, under bark or stones. They mate in the spring, and females lay their eggs in the soil. Egg and larval stages are completed through the spring and summer, and the new adults appear in late summer to early autumn. Individuals may live for two years. European ground beetles have large mandibles which they use to feed on soft-bodied prey like slugs, earthworms, and caterpillars; the larval beetles are also fierce predators. They are good to have in your garden! Like many ground beetles, this species can emit a very smelly (but otherwise harmless) substance from glands in its abdomen if you pick it up. European ground beetles have nonfunctional hind wings and cannot fly.

Ladybird Beetle
Ladybird Beetle, photo by Bud Logan
This is one of the most beneficial families of beetles because adults and larvae of most species of Ladybird Beetles feed on pest insects like aphids. A few species like the Mexican bean beetle and the squash beetle are plant-eating and can be major pests of cultivated crops.

Ladybird Beetles are usually rounded or oval in shape and often brightly colored insects. Many ladybird beetles have spots or bands on the front wings, and they have short antennae.

When we were kids and we would see one, we would all say the poem, “Ladybird, ladybird, fly away home, your house is on fire and your children are alone” not sure why we would say that.

Everyone loves seeing them, it must be the colors and peaceful look to them but they are voracious to aphids and in both larvae and adult stage, they consume large amounts of them.

Ladybugs lay eggs by the hundreds where there are aphids or other plant-eating insects. When they hatch, the ladybug larvae feed on aphids with a large appetite. The larvae are elongate and moderately flattened, and they are covered with tubercles or spines and are black with small orange or white markings.

The larvae go through a molt three times before pupating. They attach themselves to leaves, stems or rocks in an orange and black pupa. The newly emerged adult is yellow but its wings soon harden and they begin to get their spots.

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