unit 3: Pest and Vector Biology Flashcards
Hierarchical Classification of Arthropods
- Kingdom -Animalia (animals)
- Phylum-Arthropoda (the arthropods-insects, spiders, centipedes, etc.)
- Class-Insecta (insects), Arachnida (spiders,scorpions, mites, ticks, etc)
- Order-Larger groupings of broadly related insects, arachnids, etc
- Family-smaller groupings
- Genus-Closely related organisms
- Species- specific name for each
Characteristics of All Arthropods
- A hard exoskeleton (external skeleton)
- Paired jointed appendages (legs, antennae, mouthparts, etc.)
- A ventral nervous system
- A dorsal circulatory system
- A tubular digestive system
- Specialized mouthparts
specialized mouthparts of arthropods
1.chewing-modified jaws for chewing (like leaves, wood, and other bugs)-spider
2. Piercing/Sucking- modified for penetrating surfaces and sucking up liquids (like nectar,blood)-bee,mosquito
3.Sponging/Lapping-modified for sponging up liquids (like decaying matter)-fly
Class Insecta
•3 body regions: HEAD,THORAX,ABDOMEN
•3 pairs of legs on the lorax
•most insecta have 2 pairs of wings on the thorax in the adult stage, *exceptions flies-1 pair of wings & Lice,Fleas, Bed bugs-no wings
•1 pair of antenna on the head (usually); compound eyes
Examples of medically importance-mosquitos, house flies, fleas, and lice
Class Arachnida
•Two body regions (cephalothorax & abdomen)
•simple eyes
•4 pairs of legs as adults ( ticks and mites have 3 pairs of legs in their larval stage)
•Arachnids do not have wings or antennae
Examples: spiders, ticks, mites, & scorpions
Class Chilopoda
•1 pair of legs per body segment
•front set of legs modified as poisonous claws
•fast moving
•predaceous-living by preying on others
Example-Centipedes
Class Diplopoda
•2 pairs of legs per body segment
•slow moving
•Phytophagous-feeding on plants
•several secrete/spray noxious fluids
Example millipedes
Metamorphosis
the change in physical appearance from immature to adult stage. The medically important arthropods undergo either Gradual or complete metamorphosis
Gradual or Incomplete (no pupa stage) Metamorphosis-
immature insects (nymphs) resemble the adults, principal changes during growth are size and other structures(e.g. wings)Nymphs and adult live in the same habitat(e.g. cockroaches). consists in of egg, nymph, and adult.
Complete Metamorphosis-
immature insects look completely different from the adults and have different behaviors and habitats(e.g. flies and beetles). Consists of egg,larva, pupa, and adult.
Example of Complete Metamorphosis
mosquito larvae are strictly aquatic and once the adults hatch from the water they will only return to lay eggs on the surface
Other Life cycles-
arachnids,chilopods, and diplopods undergo very little metamorphosis during development. When hatched they look like
miniature adults without developed genitalia
Beneficial Arthropods
important in pollinating crops (e.g. corn,fruits& vegetables) some produce products like honey and silk, and other provide biological control of pests reducing the need to use chemicals
Pest/Harmful Arthropods
insects that negatively impact peoples lives to varying degrees, ranging from being a nuisance to large-scale disease transmission
Examples of Pest/Harmful Arthropods
•Destructive-pest that destroy field crops, ornamental plants, lawns,wooden structures, and stored food products
•Nuisance-arthropods whose presence does not pose a “traditional health threat” Ex. Annoyance, Dermatitis/dermatosis,infestation
Entomophobia
is the irrational fear of insects and the harm that they cause
Delusory Parasitosis
is the persistent,sincere, but mistake belief that arthropods are infesting a person or his/her personal space
Disease Vector
arthropods vector human infections biologically such as Malaria, West Nile Virus, Lyme disease, and Typhus. These types of infections are typically the result of a bite by an infected arthropod. Other disease such as Tularemia and a Chagas are vectored mechanically. Mechanical transmission of disease pathogens occur when a vector transports organisms on its’ feet, body hairs and other body surfaces to the host.
Allergic Reaction
the over-reaction of the body’s natural defense that present clinically as exaggerated or atypical signs/symptoms. Dermal of respiratory reactions caused by saliva, body parts and fecal matter
Envenomation
venoms are poisonous chemicals secreted by certain animals (snakes, scorpions, bees, etc) and transmitted to prey or an enemy by biting, stinging, or other mechanisms
Examples of Envenomation Mechanism
•Biting/Piercing mouthparts-deliver venom through hollow mouth parts. Some arthropods “pierce and chew” while other “pierce and suck”
•Stinging-stingers, which are used by bees, wasps, ants, and scorpions to deliver the venom by modified ovipositor at the end of the abdomen
•Urticating arthropods carry their venom within hollow body hairs and it’s released when the hairs break off and imbed into the victim
•Vesicating arthropods carry their venom within their bodies and release it through the rupture of membranes in the leg joints or other segmented areas of the body. Once realesed onto the skin, the venom causes large painless blisters. Blister beetles are the only vesicating insects in North America
