Leaf Beetles (Chrysomelidae)

Some beetles are a pest in agriculture, e.g. the Colourado Beetle does a lot of damage in potato fields. Another example of a pest is the Common Asparagus Beetle. This beautiful little beetle lives on asparagus and both the larvae and adults nibble on the leaves. It belongs to a family of smaller beetles, known as leaf beetles. Many species can be a pest at times in agriculture, gardens or parks.

This is the harmful Asparagus Beetle (Crioceris asparagi), a beautiful leaf beetle.

The beautiful Scarlet Lily Beetle below to the left is also a serious pest in many gardens. Both the red beetle and its larvae love lilies and fritillaries. They can do so much damage to the plant, it'll actually die in the end. The best way to fight them is to catch each individual beetle and kill it. Unless you have a lot of lilies in your garden of course... This is a newcomer to Britain. First discovered in the 1940's the animal is now present in most parts of England and some parts of Ireland. Except for the Cardiff region it is still absent from Wales and Scotland. Common in our everyday garden is the Alder Leaf Beetle, below to the right. It is a very small, black leaf beetle with a blueish reflection. In larger numbers it can become a pest, though.

To the left: the extremely infamous Lily Beetle (Lilioceris lilii), also called Scarlet Lily Beetle. To the right: not harmful in gardens usually: The Alder Leaf Beetle (Agelastica alni).

The beautiful Cereal Leaf Beetle below is extremely notorious in agriculture. Especially the larvae are capable of destroying entire harvests. Originating from Europe this species can now be encountered all over the world. Only introduced in the USA in 1962, the animal conquered almost all states and is now considered one of the most devastating pests. There are a few similar species and even though we are quite convinced this is Oulema melanopus (also known as Lema melanopus in the past) a mix up with the very similar Oulema duftschmidi is imaginable.

The beautiful, but much feared Cereal Leaf Beetle (Oulema melanopus).

The most dreaded leaf beetle probably is the Colourado Potato Beetle below. It used to destroy potato crops completely. This is mainly due to the fact that it multiplies very quickly indeed: three weeks after being laid an egg goes through all stages of beetle life and is an adult itself, capable of laying eggs. And each female will lay some 500 eggs! Yet, this once was a scarce beetle. It used to live in a small portion of the State of Colourado. It used only a small amount of food plants (nightshades only) and was considered a rarity by coleoptorists. But then the potato arrived. This is a member of the nightshade family as well. The Colourado Potato Beetle quickly adapted himself to eating potatoes and soon it became so abundant that it destroyed potato crops all over the US. By the mid-1800's it was imported to Europe, where it soon became as destructive as it used to be in the USA. All kinds of pesticides were used to kill the animal, but usually in vain, for the animal quickly immunized itself to most insecticides. The best definition I ever read about this beetle is this one: the Colourado Potato Beetle is a beetle still mad at us for eating his potatoes. The animal does not really look like most other leaf beetles, but rather like a large Lady Beetle. It suddenly turned up in our garden in the summer of 2004.

Known by almost all, seen by a few: the Colourado Potato Beetle (Leptinotarsa decimlineata).

The species below is very remarkable indeed. It is able to hide under its enlarged chitinepaltes completely. In English this group of Leaf Beetles is known as Shield Beetles or Tortoise Beetles. In Western Europe there are over 30 species, many of which really look like one another. This remarkable creature found in our garden turns out to be Cassida vittata.

This typical Shield Beetle (Cassida vittata) behaves just like a turtle.

Within the large family of Leaf Beetles the Shield Beetles are not the only remarkable species. Another strange group is called Flea Beetles. These are very small beetles (2 to 4 mm only) with powerful hind legs. These are used to jump. That's how these beetles got their name. Some do some damage to plants by eating small holes in the leaves. The number of flea beetles is rarely high enough to do serious damage, though. The pictures below are of a brown species and the antennae has 11 segments. This information, combined with the shape gave Mr. Frank Koehler of the famous german beetle site http://www.koleopterologie.de the opportunity to name its genus: Longitarsus. It is impossible to name the exact species from just these pictures.

Only 3 mm is this Flea Beetle, belonging to the genus Longitarsus.

Below another very small, blueish black leaf beetle. It does look like all the others, but this time we know its name: Haltica oleracea, also known as Altica oleracea. We know this not by looking at the creature, but by examining the plant it lives on. In our garden it lives only on our Evening Primrose. And this is the only species known to inhabit this plant. It appears in April, almost as soon as the plant starts growing and makes the leaves look miserable, with yellow spots and lot of small holes. Later in May the plant certainly grows more quickly than the attackers can eat and starts to look more representable, still covered in these very small insects. From then on a kind of balance is reached and the plant seems to be effected only slightly. This blue flee beetle is known from many plants, including some important ones in agriculture, such as strawberry and turnip.

This is another flea beetle, making our Evening Primrose look miserable: Haltica oleracea, also known as Altica oleracea.

The larvae of the small leaf beetles usually are inconspicuous, even though the pink larva of the Colourado Beetle is quite striking. The larva of Altica oleracea is easily overlooked though: small, brownish and slowly moving. It too eats from the leaves of various plants, including the Primroses in our garden. And, let's be honest, beautiful is not a word that jumps to mind looking at the little rascal.

How the ugly larva to the left may turn into the beautiful little beetle to the right is one of nature's great mysteries. We are looking at Altica oleracea again.

All pictures © Hans Arentsen (info@gardensafari.net) and © Hania Arentsen (photog@gardensafari.net).

Also visit Hania's Photographer's Pages, including pictures from Holland, Germany, China, the USA and Malaysia.