Beetles

(Cleridae) This family is not widely spread. It includes slightly less than 3,500 species, most of which live in tropical and sub-tropical regions. Larvae and adults are predators living on the same species of host. There are some species that live on trees, shrubs, trunks, branches or in tunnels inside their preys. Some species feed on flowers and pollen while others feed on fodder.

(Elateridae) This is one of the most important families. It includes more than 10,000 species distributed all over the world on all plants. They exist on plant cover and many of them are herbivorous. Some species live in rotten wood while others form groups under stones. Larvae live in various environments such as soil, garbage, rotten wood and termite nests. Some species are considered pests of multiple families for cultivated plants.

(Tenebrionidae) This family is very important and it includes about 19,000 species distributed into more than 2,000 genera. The species exist mainly in tropical and temperate regions of the world. They exist in various groups of families: in rotten wood, fungi, caves, burrows, nests of vertebrates, colonies of ants and termites. Some species cause damages to stored foodstuff such as grains and crop. Many species live in very specialized environments in the most arid regions of the world. In Qatar, this family is one of the best of what the family represents. Five new species have been registered, classified and added for the first time to the encyclopedia of world insects.

(Carabidae) This family has more than 40,000 species and it is one of the most important families of the Coleoptera order. It is found all over the world and includes various families. As adult, it lives most of its life on the ground surface whereas larvae can usually be found under the ground. However, some of its species can be found on trees or living on tree branches. Larvae and adults are mainly predators but they can also eat seeds and sometimes cause damage to crops and stored food materials.

(Buprestidae) This family includes more than 10,000 species type spread all over the world. Jewel beetles live in most tropical forests. The adult insects are usually so colourful with beautiful metallic glitter. Larvae are saproxylophages or, sometimes, xylophages and can be found on different species of trees. Due to the damage they cause, they can be harmful to fruit trees. Larvae of some species are leaf-miners and they are completely herbivorous. Adult insects live on flowers and they are heliophilous and thermophilous.

(Coccinellidae) This family includes about 6,000 species living mainly in tropical and sub-tropical regions. The family is economically important as larvae and adults are generally predators feeding often on aphids, chrysomphalus, moths and thrips, and on larvae of butterflies, Hymenoptera and Diptera orders in their first stages. Some beetles feed on weeds and attack crops and some are used for biological control.

(Chrysomelidae) This family includes slightly more than 35,000 species existing worldwide. Larvae and adults are mainly herbivorous, and some, depending on the species, are more or less connected to a group of plant families. The species of this family often exist in groups on tree leaves and weeds. Some species of this family, such as Bruchids, exist on seeds of fodder plants, inside which they complete their cycle and their larvae grow. Some species are very harmful to agricultural plants and stored foodstuff. Many of these species are toxic as they have developed a system of chemical defense.

(Cerambycidae) This family includes more than 20,000 species existing worldwide. Adults exist mainly on trunks and branches of dead trees. Some species can also be seen on tree trunks, flowers, wild weeds, and on the ground. Larvae are mainly saproxylophages or, in some species, xylophages, rhizophages or stem-eaters.

(Scarabaeidae) This family of Coleoptera order includes more than 30,000 species globally distributed. They live in incredibly various environments and larvae and adults may exist in the same or different environments. They can be found in compost, carrion and mushrooms and on plants. They can feed on pollen, fruits, decaying organic materials or roots depending on species. Some species of this family live in nests of ants, termites, rodents or birds. Other species live and reproduce in dung of various mammals. Some species are of importance economically, either due to their role in fertilizing or helping with the recycling of leaves and roots of agricultural crops damaged by other herbivorous insects.

(Hybosoridae) This family includes slightly more than 200 species divided into 30 genera. Its species are mainly tropical and their biology is not completely understood. It seems that larvae live in decaying plant materials. Some species have been found on the remains of invertebrates and vertebrates during their decomposition, whereas other species can be found in droppings or in layers of cut grass. Adults are usually attracted by light.

(Dryophthoridae) This family has been separated from the Curculionidae family and it is not diversified. Larvae and adults are and related with different groups of plants such as palm, orchid, bromelias and lilies. Some species cause damages to stored grain, corn crops and bananas. Larvae generally dig tunnels and develop inside stems of plants.

(Curculionidae) Along with Carabidae and Staphylinidae families, this family is one of the most important families of the Coleoptera order. It includes slightly more than 50,000 species spread throughout the world, and more than 400 genera. The classification in this family still needs some clarification in terms of subclasses and tribes as some specialists have disagreement about that. Weevils (snout beetles) (Curculionidae) family is close to Apionidae and Nanophigedae families. Larvae and adults are herbivorous and can attack all parts of plants according to species. They can cause considerable damage to crops and stored crops.