ectoparasitism

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ectoparasitism

biology

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June 25, 2026

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Ectoparasitism is a form of parasitism where the parasite lives on the exterior of its host. These external parasites, known as ectoparasites, can include organisms like ticks, fleas, leeches, and lice. While they live on the host's body surface, they do not typically cause disease themselves. However, ectoparasites can transmit disease-causing organisms, such as bacteria responsible for Lyme disease or plague. Some examples of ectoparasitic diseases include myiasis, pediculosis (lice infestation), and scabies. The life cycles of some ectoparasites, like certain flatworms (Monogenea), involve a free-swimming larva that must attach to a host to mature.12345

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braconid wasp
Natural history and parasitism
…living within their hosts, or ectoparasitic, living on their hosts. Endoparasitic adult females lay an egg or eggs in the larvae or eggs of the host (braconid wasps do not typically exploit adult hosts). Many species are egg-larval parasitoids, meaning the wasp eggs are laid within the host eggs but…
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…living within their hosts, or ectoparasitic, living on their hosts. Endoparasitic adult females lay an egg or eggs in the larvae or eggs of the host (braconid wasps do not typically exploit adult hosts). Many species are egg-larval parasitoids, meaning the wasp eggs are laid within the host eggs but…
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parasitism
Parasites may be characterized as ectoparasites—including ticks, fleas, leeches, and lice—which live on the body surface of the host and do not themselves commonly cause disease in the host; or endoparasites, which may be either intercellular (inhabiting spaces in the host’s body) or intracellular
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Parasites may be characterized as ectoparasites—including ticks, fleas, leeches, and lice—which live on the body surface of the host and do not themselves commonly cause disease in the host; or endoparasites, which may be either intercellular (inhabiting spaces in the host’s body) or intracellular
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plant disease
Nematode diseases
Many important ectoparasites feed on plant roots—dagger nematodes (Xiphinema), stubby-root nematodes (Trichodorus), spiral nematodes (Rotylenchus and Helicotylenchus), sting nematodes (Belonolaimus), and pin nematodes (Paratylenchus). Leaf, or foliar, nematodes (Aphelenchoides species) and bulb and stem nematodes (Ditylenchus dipsaci) cause severe losses in vegetable and ornamental bulb crops, clovers
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Many important ectoparasites feed on plant roots—dagger nematodes (Xiphinema), stubby-root nematodes (Trichodorus), spiral nematodes (Rotylenchus and Helicotylenchus), sting nematodes (Belonolaimus), and pin nematodes (Paratylenchus). Leaf, or foliar, nematodes (Aphelenchoides species) and bulb and stem nematodes (Ditylenchus dipsaci) cause severe losses in vegetable and ornamental bulb crops, clovers
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flatworm
Development
…majority of the Monogenea are ectoparasitic (externally parasitic) on fish. The eggs hatch in water. The larva, known as an oncomiracidium, is heavily ciliated (has actively moving hairlike projections) and bears numerous posterior hooks. It must attach to a host before it can grow and mature. In some species (e.g.,…
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…majority of the Monogenea are ectoparasitic (externally parasitic) on fish. The eggs hatch in water. The larva, known as an oncomiracidium, is heavily ciliated (has actively moving hairlike projections) and bears numerous posterior hooks. It must attach to a host before it can grow and mature. In some species (e.g.,…
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