Diptera order
1. Gnats
2. Midges
3. Mosquitos
Dipteran biology
- adults: typically diurnal, active
- larvae: relatively immobile, or sedentary
- eggs: laid in or near moist environments
Flies are excellent aerialist
- they can hover, fly backwards, turn in place, and even fly upside down to land on a ceiling
Dipteran Morphology
- lack true legs, but occasionally there are spines
- primitive flies
- culiciform-type larvae
Vermiform-type larvae
- generally called maggots
Dipteran courtship and mating
- sound
- vision
- leks
sound dipteran mating
wingbeat frequencies of females detected by male antennal organ: mosquitoes
Vision dipteran mating
swarms of male flies over prominent landmarks, or males aggregate around a larval food resource in which females will lay eggs (some dung flies)
Leks dipteran mating
males gather in places not associated with a resource and display/defend territories
Why diptera are so successful
1) adults and larvae in separate niches
2) adults excellent dispersers (some black flies up to 450 km!)
3) larvae adapted to nutritious decay
4) short generation time for many species (7-10 days)
5) common worldwide, but become the dominant insect group i
Family Tipulidae
Crane flies
Crane flies
- stilt-like legs that parts of may be easily shed (defensive mechanism)
- Larvae: important soil engineers
Midges
- refers to several families of fly
- Some may look similar to mosquitoes�but they aren't!
- small flies
Midges: Small flies
- While many midges are non-biting to humans (~87%), there is a family of biting midges (Ceratopogonidae). �
- Biting midges: extremely annoying, but have not been found to vector diseases to humans in the U.S.
Family psychodidae
- Subfamily phelebotominae
- sandflies
Sandflies
Females: blood-feeding Host selectivity: variable Can vector human diseases
Family Tabanidae
- Horse and Deer Flies pic horse fly
Horse and Deer Flies
- Adults: stout bodied powerful fliers with large eyes and excellent vision
- Pests: painful bite, blood loss (why?_
- Diseases vectors of anthrax, tularemia, and African Eye Worm
- Important pollinators
- Horse flies: prefer stationary hosts
- Deer flies
Deer Fly Lifecycle
- Adult Females: blood feeders
- Adult Males: nectar feeders
Family Asilidae
Robber Flies
Robber Flies
- Predacious, some bumblebee mimics
- Key characters:
(1) Stylate mouthparts surrounded by a hairy beard
(2) Concave depression on top of head between compound eyes
Family Muscidae
Tsetse Fly
Tsetse Fly
Key characters:
(1) Tsetse fold their wings so that one wing rests directly on top of the other.
(2) long proboscis, which extends forward
Unusual life cycle of Tsetse
adenotrophic viviparity
1. fertilize one egg at a time and retain each egg within their uterus to have the offspring develop internally
2. Female feeds larva from modified uterine gland
3. as 3rd instar, larva leaves uterus and crawls into ground to pupat
Family Calliphoridae
Blow Flies
Blow Flies
- Adults: occasional pollinators, nectivorous
- Larvae: scavengers of carrion and dung
- can locate dead flesh within min
Blow fly life cycle
1. egg (23 hrs)
2. three larval stages (27 hrs)
3. pupa (22 hrs)
4. adult (130 hrs)
(6 parts total and 70 degrees f, ea. stage in blow fly life takes a known amount of time to complete)
What can we learn from the insects?
- ID species, determine where they are in the life cycle�then back track to get Postmortem Interval (PMI)
Family Simuliidae
Black flies
Black flies
- Long distance foraging: females will fly up to 10 miles in search of a blood meal.
- Adults are major nuisance pests
- PAINFUL bite
Phorid flies
some are parasitoids of ants and can be used in biocontrol (decapitate head)
Biocontrol
the control of a pest by the introduction of a natural enemy or predator
Ant-decapitating Phorid flies
typically species specific and often caste specific
The Family Culicidae
Mosquitoes
Mosquitoes
1. Anophelinae (subfamily) - Anopheles species �
2. Culicinae (subfamily) - Aedes, Culex, Haemagogus, Mansonia, Ochlerotatus and all other genera
- don't glow green under uv light
Mosquito Feeding Behavior
- females: blood is used for egg development
- males: pollinate
Mosquito bites prevented
1. cover skin
2. mosquito nest
3. mosquito breeding sites
4. repellent
5. use screens or mosquito nests
Toxorhyncites
mosquitoes do not bloodfeed (consume other mosquitos)
ex: culex mosquito
Culex Mosquitoes
- Feeds on birds, mammals, and reptiles
- Disease vector (various forms of encephalitis, WNV)
Aedes Mosquitoes
- Usually black and white stripes on body and legs
- Bite during the day
- Disease vectors: dengue, yellow fever
Anopheles Mosquitoes
- Host specificity: variable
- Difficult to control: Bite indoors and outdoors/ Bite during day or night
- have spiracles so need to be at the top of water
- Vector of mammalian malaria, canine heartworm, various viruses
Anapholes vs culex
- C: down in angle allows them to breathe/ lay eggs tightly packed/ short palps/ usually transparent wings
- A: lie down parallel to water/ lay eggs singularity/ Mouth long palps/ spotted wings
Mosquito control
- Aim at adults
- Use pesticide but when we use lots of it they become resistance to it
- solution: switch pesticide but very costly/sterile male releases/ genetically modified males