The stylostome is a funnel- or channel-like structure formed in response to trombiculid mites. The formation is not caused by the mouthparts of the mites, because these mites do not have needle-like mouthparts as hematophagous animals have been known to have, but have chelicerae, which only pierce the skin. The tube is formed by the digestive enzymes in the saliva, which are the same salivary secretions that break down cells and cause the surrounding tissue to harden. [1] As the mite feeds longer, the saliva seeps further down, digesting more tissue and causing the stylosome to penetrate to lower layers of skin. [2]
Normally, the bite mark causes local swelling or welts, but in more serious cases it causes dermatitis. The mite can be infected with a disease called scrub typhus in Asia and the Pacific and can transmit the disease by carrying saliva directly into the blood stream, but mites in North America have not been known to transmit Lyme disease, Rocky Mountain spotted fever, tularemia or any other disease.
Mosquitoes, the Culicidae, are a family of small flies consisting of 3,600 species. The word mosquito is Spanish and Portuguese for little fly. Mosquitoes have a slender segmented body, one pair of wings, three pairs of long hair-like legs, and specialized, highly elongated, piercing-sucking mouthparts. All mosquitoes drink nectar from flowers; females of some species have in addition adapted to drink blood. Evolutionary biologists view mosquitoes as micropredators, small animals that parasitise larger ones by drinking their blood without immediately killing them. Medical parasitologists view mosquitoes instead as vectors of disease, carrying protozoan parasites or bacterial or viral pathogens from one host to another.
Ticks are parasitic arachnids of the order Ixodida. They are part of the mite superorder Parasitiformes. Adult ticks are approximately 3 to 5 mm in length depending on age, sex, species, and "fullness". Ticks are external parasites, living by feeding on the blood of mammals, birds, and sometimes reptiles and amphibians. The timing of the origin of ticks is uncertain, though the oldest known tick fossils are from the Cretaceous period, around 100 million years old. Ticks are widely distributed around the world, especially in warm, humid climates.
Hemiptera is an order of insects, commonly called true bugs, comprising over 80,000 species within groups such as the cicadas, aphids, planthoppers, leafhoppers, assassin bugs, bed bugs, and shield bugs. They range in size from 1 mm (0.04 in) to around 15 cm (6 in), and share a common arrangement of piercing-sucking mouthparts. The name "true bugs" is often limited to the suborder Heteroptera.
Mites are small arachnids. Mites span two large orders of arachnids, the Acariformes and the Parasitiformes, which were historically grouped together in the subclass Acari. However, most recent genetic analyses do not recover the two as each other's closest relative within Arachnida, rendering the group non-monophyletic. Most mites are tiny, less than 1 mm (0.04 in) in length, and have a simple, unsegmented body plan. The small size of most species makes them easily overlooked; some species live in water, many live in soil as decomposers, others live on plants, sometimes creating galls, while others are predators or parasites. This last type includes the commercially destructive Varroa parasite of honey bees, as well as scabies mites of humans. Most species are harmless to humans, but a few are associated with allergies or may transmit diseases.
Whiteflies are Hemipterans that typically feed on the undersides of plant leaves. They comprise the family Aleyrodidae, the only family in the superfamily Aleyrodoidea. More than 1550 species have been described.
Colorado tick fever (CTF) is a viral infection (Coltivirus) transmitted from the bite of an infected Rocky Mountain wood tick (Dermacentor andersoni). It should not be confused with the bacterial tick-borne infection, Rocky Mountain spotted fever. Colorado tick fever is probably the same disease that American pioneers referred to as "mountain fever".
An itch is a sensation that causes a strong desire or reflex to scratch. Itches have resisted many attempts to be classified as any one type of sensory experience. Itches have many similarities to pain, and while both are unpleasant sensory experiences, their behavioral response patterns are different. Pain creates a withdrawal reflex, whereas itches leads to a scratch reflex.
Trombicula, known as chiggers, red bugs, scrub-itch mites, or berry bugs, are small arachnids in the Trombiculidae family. In their larval stage, they attach to various animals and humans, then feed on skin, often causing itching and trombiculosis. These relatives of ticks are nearly microscopic, measuring 0.4 mm (0.01 in) and have a chrome-orange hue. A common species of harvest mite in North America is Trombicula alfreddugesi.
Tungiasis is an inflammatory skin disease caused by infection with the female ectoparasitic Tunga penetrans, a flea also known as the chigoe, chigo, chigoe flea, chigo flea, jigger, nigua, sand flea, or burrowing flea. The flea and the disease that it causes are found in the tropical parts of Africa, the Caribbean, Central and South America, and India. Tunga penetrans is the smallest known flea, measuring 1 mm across. It is also known in Latin America as the nigua and bicho de pie (Spanish) or bicho de pé (Portuguese), literally "foot bug". Tunga penetrans is a member of the genus Tunga, which comprises 13 species.
The discipline of medical entomology, or public health entomology, and also veterinary entomology is focused upon insects and arthropods that impact human health. Veterinary entomology is included in this category, because many animal diseases can "jump species" and become a human health threat, for example, bovine encephalitis. Medical entomology also includes scientific research on the behavior, ecology, and epidemiology of arthropod disease vectors, and involves a tremendous outreach to the public, including local and state officials and other stake holders in the interest of public safety.
Orientia tsutsugamushi is a mite-borne bacterium belonging to the family Rickettsiaceae and is responsible for a disease called scrub typhus in humans. It is a natural and an obligate intracellular parasite of mites belonging to the family Trombiculidae. With a genome of only 2.0–2.7 Mb, it has the most repeated DNA sequences among bacterial genomes sequenced so far. The disease, scrub typhus, occurs when infected mite larvae accidentally bite humans. This infection can prove fatal if prompt doxycycline therapy is not started.
In epidemiology, a disease vector is any living agent that carries and transmits an infectious pathogen such as a parasite or microbe, to another living organism. Agents regarded as vectors are mostly blood-sucking insects such as mosquitoes. The first major discovery of a disease vector came from Ronald Ross in 1897, who discovered the malaria pathogen when he dissected the stomach tissue of a mosquito.
The health of domestic cats is a well studied area in veterinary medicine.
Psoroptes is a genus of mites, including the agents that cause psoroptic mange.
Trombiculidae, commonly referred to in North America as chiggers and in Britain as harvest mites, but also known as berry bugs, bush-mites, red bugs or scrub-itch mites, are a family of mites. Chiggers are often confused with jiggers – a type of flea. Several species of Trombiculidae in their larva stage bite their animal host and by embedding their mouthparts into the skin cause "intense irritation", or "a wheal, usually with severe itching and dermatitis". Humans are possible hosts.
Many species of arthropods can bite or sting human beings. These bites and stings generally occur as a defense mechanism or during normal arthropod feeding. While most cases cause self-limited irritation, medically relevant complications include envenomation, allergic reactions, and transmission of vector-borne diseases.
Brevipalpus is a genus of mites in the family Tenuipalpidae, the flat mites. The genus includes several species that are among the most important economic pests in the flat mite family.
Mites that infest and parasitize domestic animals cause disease and loss of production. Mites are small invertebrates, most of which are free living but some are parasitic. Mites are similar to ticks and both comprise the order Acari in the phylum Arthropoda. Mites are highly varied and their classification is complex; a simple grouping is used in this introductory article. Vernacular terms to describe diseases caused by mites include scab, mange, and scabies. Mites and ticks have substantially different biology from, and are classed separately from, insects. Mites of domestic animals cause important types of skin disease, and some mites infest other organs. Diagnosis of mite infestations can be difficult because of the small size of most mites, but understanding how mites are adapted to feed within the structure of the skin is useful.
Mites are small crawling animals related to ticks and spiders. Most mites are free-living and harmless. Other mites are parasitic, and those that infest livestock animals cause many diseases that are widespread, reduce production and profit for farmers, and are expensive to control.
Many species of flies of the two-winged type, Order Diptera, such as mosquitoes, horse-flies, blow-flies and warble-flies, cause direct parasitic disease to domestic animals, and transmit organisms that cause diseases. These infestations and infections cause distress to companion animals, and in livestock industry the financial costs of these diseases are high. These problems occur wherever domestic animals are reared. This article provides an overview of parasitic flies from a veterinary perspective, with emphasis on the disease-causing relationships between these flies and their host animals. The article is organized following the taxonomic hierarchy of these flies in the phylum Arthropoda, order Insecta. Families and genera of dipteran flies are emphasized rather than many individual species. Disease caused by the feeding activity of the flies is described here under parasitic disease. Disease caused by small pathogenic organisms that pass from the flies to domestic animals is described here under transmitted organisms; prominent examples are provided from the many species.