Diptera and Hemiptera Entomology Flashcards
what are diptera
- One pair of functional wings
- Hindwings modified to form halteres
- Flies, mosquitoes, midges, gnats
diptera - Wings
- Single pair of membranous front wings
- instead of hind wings, they have halteres
diptera: wings - what are halteres
- reduced hind wings that form a pair of balancing organs
- beat at the same frequency as wings, but out of phase
dipera: wings - what do halteres allow the insect to do
- Hover
- Fly backwards
- 360 degree turns
- Upside down flight and landing
explain the Indirect flight muscles
- Indirect flight muscles attach to thorax, not wings
- Muscles flex thorax, thorax flaps wings
- Asynchronous
- Enables high wingbeat frequency
indirect flight muscles - asynchronous
multiple contractions from single nerve impulse
indirect flight muscles - Enables high wingbeat frequency
can be higher than fastest possible neural re-polarization rate
diptera - what are some of their niches
- Pollinators
- Predators
- Blood feeders
- Herbivores
- Parasitoids
- Scavengers
diptera - explain their mouthparts
May be:
- sponging (e.g., housefly)
- Biting (e.g., horsefly)
- Piercing sucking (e.g., mosquito)
diptera - Pollinators
- Bee flies and hoverflies are pollinators
- both feed on nectar as adults
- but as larvae, bee flies are parasitoids and hoverflies are predators
diperta - Predators
- Robberfly kills honeybee with piercing-sucking mouthparts
- fly mimics a bumblebee
diptera - Blood feeders
- Not just mosquitoes, diptera may use biting, rather than piercing/sucking mouthparts
- Horsefly feeds from pool of blood
- Sandfly feeds on human blood
diptera - scavengers
- Along with Cleopatra, flies are the most important order for consuming feces and carrion
- Progression of species on carrion is the basis for forensic entomology
how does the botfly lay eggs
1) female catches mosquito in flight, attaches eggs
2) mosquito finds mammal host; body heat causes 1st instar larvae to drop from eggs onto mammal
3) larvae burrows into host, feeds on blood
4) when done feeding, larva emerges from host to pupate in soil
explain the three broad categories of insect attacks
- Direct harm: venoms and other chemical defenses
- Allergic reactions, often in conjunction with the above
- Vectors of other disease-causing organisms
When insects attack humans – tissue feeders
Myiasis: when fly maggots develop in living flesh, often exploiting existing injury (e.g., infected mosquito or tick bite)
when insects attack humans - explain Maggot therapy
some maggots eat only dead tissue – put them on a nasty wound, they clean it by consuming the dead, infected parts
When insects attack huamns– blood feeders
- Blood feeders have evolved in multiple orders
- Generally, the direct effects of these are irritating (itches, potential infection) but not life-threatening
- The serious effects come from parasites vectored by insects (except bedbugs)
when insects attack humans: blood feeders - where have blood feeders evolved
- Hemiptera
- Reduviidea (subfamily Triatominae)- kissing bugs
- Cimicidae – bedbugs
- Pthiraptera – lice
- Diptera has many groups, mosquitoes most prominent
- Also: Siphonaptera – the fleas
- Also: Ticks (not insects), but prominent arthropod blood feeders
diptera - explain malaria
- Malaria is a mosquito-borne infectious disease caused by the parasite Plasmodium falciparum
- Malaria is transmitted by the infected female mosquito Anopheles
- Remember, piercing sucking mouthparts – the dirty syringes of nature
what are the Siphonaptera
- fleas
- wingless
- Can use natural elasticity of cuticle for huge jumps
- All ectoparasites, mostly mammals (few birds)
- Piercing sucking mouthparts
- Laterally flattened (i.e., ‘skinny’), mostly ectoparasites are dorso-ventrally flattened
siphonaptera - explain the black death
- Fleas are the vector, bacteria Yersinia pestis the pathogen
- Primarily flea-rodent disease, but when fleas can’t find rats to bite, they go for humans
- Bacteria infects flea, blocks the gut so that flea regurgitates when it feeds
- Will thus regurgitate bacteria into new hosts when feeding
- Bc flea cant get food, its starving, and feeds more and more aggressive
