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| ...eneus and Western corn rootworm are able to destroy entire harvests. Furthermore Bark beetles, Ips typographus, the Old-house borer and Mountain pine beetles destroy wooden structures, forests and woods. The Asian ladybird is among those considered useful , as it is the enemy of many pests in agriculture and forestry. | | |
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| ...tle fly uses its proboscis to suck up liquids from carrion and nectar from flowers. The female common green bottle flies lay their eggs on carrion, which the larvae then feed on when they hatch.
The Common green bottle fly larvae are considered useful as they are used as fishing bait, animal feed and today (once again) in the treatment of wounds.
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| Green lacewings | | ... on the chest and abdomen segments, or are plump and have long bristles on the sides of the body.
Adult green lacewings fly at night and at dawn. They feed on pollen, nectar or honeydew. There are also species that are predatory. The latter are useful in agriculture as they eat insects, mites and aphids. | | |
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| ...t among the blood-sucking insects. They feed on nectar or water. While the Nematocera have a bad reputation amongst humans because their bites can be painful and can cause allergies and transmit germs, the crane fly (larval stage) is regarded as a useful animal, because the diet and elimination behaviour of the larvae help to improve the soil. | | |
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| The European paper wasp poses no risk to humans. In fact, it is very useful as a plant pollinator and insect predator. | | |
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| The honey bee, silkworms, grasshoppers and crickets are regarded as useful by humans. Indeed crickets are part of the human diet in many countries. Furthermore in addition to their use in the pharmaceutical industry, certain insects are kept as pets in terrariums.
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| As ladybirds eat pests they are considered useful by humans. However In Europe the Subcoccinella vigintiquatuorpunctata can be harmful, especially if it occurs in alfalfa , sugar beets, clover, potatoes, carnations and dahlias. | | |
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| ...llowed out body of the aphid and after five days, the young adult wasps hatch. Some species specialize in spinning cocoons and live on their eggs.
Because the hatching wasps keep the populations of plant pests down, they are considered very useful. They are also actually used in agriculture to kill plant pests (aphids) or moths. | | |
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| ...to build cocoons under water. Air is kept in these cocoons for the larvae to breathe. Water scavenger beetles feed on plants and rotting substances. Their larvae mostly live predatorily at the bottom of water bodies. Water scavenger beetles are very useful because they purify the water. | | |
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| ...in some cases lead to mental illness (arachnophobia). Some species of spiders are in fact dangerous to humans, for example, the black widow. In Cambodia, spiders are brutally killed and eaten. However in many Asian cultures, the spider is considered useful because it kills insects. In West Africa, the spider is considered a deity. | | |
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