|
|
The beetles comprise an order of insects characterized by complete metamorphosis (including a pupal stage between the larval and adult stages), biting-chewing mouth parts, and two pairs of wings, of which the hind pair are membranous and used for flight and the front pair (elytra) are sturdy and used for protection. The approximately 350,000 known species of beetles in the world comprise the largest animal group in existence. Only 1% of this number, about 3,500 species, are found in Israel. These species represent a wide variety of families, shapes, colours and modes of life. Many species are harmful to crops and stored products, including food, while others are beneficial to mankind through preying on agricultural pests or by recycling waste products. Due to the hardness of their bodies and their tremendous resistance, variety of shapes, range of size (from 1-160 mm) and amazing colours, the beetles are a favourite group for many amateur entomologists and collectors. As a result of their habitat destruction, several species in Israel have become extinct, such as some of the large water beetles; while others are endangered. The four species depicted in the present series of stamps have been chosen as particularly representative of the Israeli landscape.
Pied ground beetle (Graphopterus serrator)
The pied ground beetle belongs to the family Carabidae (ground beetles), of which 400 species are found in Israel. Like many other species of its family, this beetle too is a predator, preying on smaller insects and other tiny creatures. Unlike most of its family, however, it is active by day, inhabiting sandy soil. It actively seeks its prey, and its long bristly legs help it scuttle swiftly over the sand. The prey is caught and chewed by the strong mandibles. The beetle's size (2.5 cm), flat shape, and colouring (white blotches on a black background) make it easy to identify. It is found in Israel from the western Negev desert as tar north as Tel Aviv, representing a more southern, desert fauna.
Copper beetle (Potosia cuprea)
This species represents the approximately 200 species of the family Scarabaeidae (lamellicorn beetles) found in Israel. Some of these beetles feed on dung, while others, including the copper beetle, feed on plants. The copper beetle is commonly seen in the field in the spring, where it can be found flying rather clumsily or feeding, mainly on thistle flower heads. Its spectacular metallic colouring, together with its large size (2.5 cm) and fan-like antennae, make it easy to identify in the field.
Ladybird (Coccinella septempunctata)
This is one of the most common, familiar and congenial beetles. In addition to its hemispherical shape (with a length of 5-8 cm) and bright colours (that warn predators ot its poisonous nature) the ladybird is exceptional in its voracity for aphids, a group of insects that includes many agricultural pests. One beetle (during both larval and adult stages) can eat thousands of aphids within its lifetime. About 70 species of ladybird beetles (Ooccinellidae) are known in Israel, and many of them help to regulate pest populations. Both in Israel and abroad, some of the species are employed for biological control of pests. At the end of spring the beetles migrate to mountain tops, such as Mt. Hermon and Mt. Meron, where they mass together. At the beginning of the following spring they migrate back to the low-lying areas - a phenomenon that has not yet been fully studied.
Yellow banded borer (Chiorophorus varius)
About 120 species of longhorned borers (Cerambycidae) are found in Israel, out of the approximately 30,000 known species of the family throughout the world. The yellow banded borer belongs to a group of species commonly found on flowers in Israel in the spring. Its elongated body (about 12 mm long) and antennae, together with its pattern of black and yellow stripes, liken it to a wasp and provide a good protection against predators. During the larval stage, most members of the family develop in, and feed on, tree trunks, branches, plant stalks and grasses, Some of the species are agricultural pests, while others damage industrial lumber and furniture. Due to the low nutritional value of wood, the larval development of these Beetles often continues for several years.