MODULE 1: Overview of Veterinary Entomology

What is the evaluation and understanding of ectoparasites that bite and feed on livestock and companion animals called?

Veterinary Entomology

What aspects of animals are affected by ectoparasites?

Thriftiness, behavior, and lifestyle

What are the major causes of mortality and reduced productivity in domestic livestock?

Insects

How do insects directly cause damage to livestock?

By feeding on or parasitizing livestock

How do insects indirectly cause damage to livestock?

By transmitting livestock diseases

Veterinary Entomology falls under what science?

Parasitology

What does Parasitology study?

Life Cycle, Morphology, Pathogenicity, Transmission, Epidemiology, and Control (diagnosis, treatment, and prevention of parasites)

What is an organism whose purpose is procuring food and shelter?

Parasite

What are the three ways a parasite may associate with another organism?

Visit briefly, take up abode temporarily, or live permanently outside or inside the body of another organism where it usually does harm

What is the symbiont that receives the advantage called?

Parasite

What is the injured or harmed symbiont called?

Host

What is the living together of two dissimilar organisms called?

Symbiosis

What are the three categories of symbiosis?

Mutualism, Commensalism (Amensalism), and Parasitism

What type of symbiosis provides reciprocal advantage to both organisms?

Mutualism

What is an example of mutualism involving a flagellate and a wood termite?

Trichonympha campanula and Temopsis nevadensis

In the mutualistic relationship between Trichonympha campanula and Temopsis nevadensis, what does the flagellate do for the termite?

Digest wood particle

In the mutualistic relationship between Trichonympha campanula and Temopsis nevadensis, what does the termite provide the flagellate?

Protection

What type of symbiosis benefits only one symbiont without harming the other?

Commensalism

What is an example of commensalism involving humans?

Entamoeba coli and the small intestine (man)

What type of symbiosis benefits one symbiont to the detriment of the other?

Parasitism

What is an example of parasitism involving pigs?

Ascaris suis and pig

What parasite briefly visits its host for nourishment but does not depend on it for nourishment or shelter?

Optional Occasional Parasite

What are examples of optional occasional parasites?

Mosquitoes and sandflies

What parasite does not permanently live on its host but depends on it for nourishment and some shelter?

Obligate Occasional Parasite

What are examples of obligate occasional parasites?

Fleas and ticks

What parasite is parasitic only during definite stages of its life cycle, when parasitism is obligate or continuous?

Determinate Transitory Parasite

What are examples of determinate transitory parasites?

Botflies and Marble Flies

What may the larvae of dipteran flies be deposited in?

Dead or living tissue

What parasite remains parasitic from hatching of the eggs until eggs are produced by the adult?

Permanent Parasite

What are examples of permanent parasites?

Lice and mange mite

What parasites cannot pass spontaneously from one host to another?

Fixed Parasites

What is an example of a fixed parasite?

Helminths

What parasite occurs in organs far remoter from its normal location?

Erratic Parasite

Where can Ascaris suis occur as an erratic parasite in pigs?

Fallopian tube and bile ducts

Where can Stephanurus dentatus occur as an erratic parasite?

Lungs

What parasites require only one host to complete their life cycle?

Monoxenous Parasites

What are examples of monoxenous parasites?

Ascaridia galli in chicken and Trichuris vulpis in dogs

What parasites require 2 or more hosts to complete their life cycle?

Heteroxeneous Parasites

What is the host in which a parasite reaches sexual maturity and forms eggs and oocysts called?

Primary host, definitive host, or final host

What is the host in which a parasite undergoes juvenile or larval development or asexual multiplication called?

Secondary host or intermediate host

What are the final and intermediate hosts of Plasmodium sp.?

Final host: Mosquito

What are the final and intermediate hosts of Fasciola gigantica?

Final host: Cattle, goat

What are the final, first intermediate, and second intermediate hosts of Paragonimus westermani?

Final host: Man

What objects resemble true parasite eggs and larvae and are often mistaken for them?

Pseudoparasites

What are examples of pseudoparasites?

Pollen grain, fungal spores, yeast cells, and plant spines

What parasites occur on the surface of the body?

Ectoparasites or External Parasites

What are examples of ectoparasites?

Ticks, lice, and mites

What condition is produced by external parasites?

Infestation

What parasites are found in the alimentary canal, blood, muscle, and other tissues of the host?

Endoparasites or Internal Parasites

What is the condition produced by endoparasites termed?

Infection

What are examples of endoparasites?

Roundworms, Plasmodia, and Coccidian

What parasites can exist as both free-living and parasitic organisms?

Facultative Parasites

What are examples of facultative parasites?

Larva of Blowflies and Flesh Flies

What condition can facultative parasites cause when they occur in tissues or wounds?

Myiasis

What final hosts harbor infection without outward signs of infection and serve as carriers?

Reservoir Hosts

What happens in reservoir hosts that allows them to remain without disease?

The organism multiply but not enough to cause a disease

What is an example of a reservoir host relationship involving Trypanosoma evansi?

Trypanosoma evansi in carabaos

What host is an unnatural host in which parasites are accidentally lodged and transmitted through ingestion?

Transport or Paratenic Host

What happens to parasites in a paratenic host?

No development and no multiplication

What is an example of a parasite using rats or birds as paratenic hosts?

Toxocara eggs ingested by rats or birds

What happens when a susceptible host eats a paratenic host containing encysted larvae?

The encysted larva develop into the adult

What host contains the adult, reproducing stage of a parasite?

Final or Definitive Host

What host is where part of the immature phase of a parasite's cycle is spent and development occurs?

Intermediate Host

Why is the intermediate host essential?

It is an essential part of the cycle

What is the developmental stage of an infection before agents produce evidence, such as eggs or oocysts, of their presence?

Prepatent Period

What is the period from infection until eggs or larvae are demonstrated or produced in feces until eggs disappear?

Patent Period

What parasites are transferable from animals to man and vice versa?

Parasitic Zoonoses

What are examples of parasitic zoonoses?

Trichinella spiralis and Entamoeba histolytica

What is the presence of parasites in the blood called?

Parasitemia

What parasite is highly specific for animals?

Zooparasite

What is an example of a zooparasite?

Oxyuris equi

What parasite is highly specific for man?

Anthropoparasite

What is an example of an anthropoparasite?

Enterobius vermicularis

What parasite is equally specific for man and animals?

Anthropozooparasite

What is an example of an anthropozooparasite?

Trichinella spiralis

What type of parasitic zoonosis requires man for the life cycle of the parasite?

Enzoonoses

What are examples of enzoonoses?

Taenia solium and T. saginata

What parasitic zoonosis is an unstable and changeable group in which man is accidentally involved?

Parazoonoses

What is an example of a parazoonosis?

Ascaris suis

What type of arthropod transmission involves no change in form or development within the arthropod?

Mechanical/Non-Cyclical Transmission

What are examples of mechanical or non-cyclical transmission?

T. evansi, Amoeba, and Helminth Ova

What type of transmission involves a change in form or development of the parasite or organism inside the arthropod?

Biological Transmission/Cyclical Transmission

What type of biological transmission involves cyclical changes and multiplication in the arthropod?

Cyclopropagative Transmission

What is an example of cyclopropagative transmission?

Plasmodia in mosquito

What type of biological transmission involves cyclic development and changes in form and size but no change in number?

Cyclodevelopmental Transmission

Does multiplication occur in cyclodevelopmental transmission?

No multiplication

What is an example of cyclodevelopmental transmission?

Dirofilaria immitis in mosquito

What type of biological transmission involves multiplication in the arthropod without cyclical development or change in form and size?

Propagative Transmission

What is an example of propagative transmission involving bubonic plague?

Yersinia pestis in the gut of the rat flea

What is transmission of infection through the next generation of ticks called?

Transovarian Transmission or Hereditary Transmission

What happens after a mature female tick ingests the parasite during transovarian transmission?

The parasite invades the developing tick egg

What happens when a young tick emerges after transovarian transmission?

It carries the infective organism

What happens to the mother tick after laying eggs during transovarian transmission?

The mother dies

What is an example of transovarian transmission?

Babesia in tick

What type of transmission occurs when the organism is transmitted by the next developmental stage of ticks?

Transstadial

What is the transport of small parasites by larger parasites called?

Phoresy

Which small parasites may be transported by flies and mosquitoes during phoresy?

Lice and mites

What happens to some fly eggs during phoresy?

They attach to the abdomen of another fly, hatch, and are deposited or transferred to another host

What is an example of phoresy involving Dermatobia hominis?

Dermatobia hominis egg in the abdomen of mosquito

How can Tabanus contribute to phoresy?

When Tabanus feeds, it could have lice attached to its leg and transfer them to another host