Diptera Morphology and Terminology Flashcards
Diptera
Order of insects containing two-winged flies
More than 125,000 species
Wide range of feeding mechanisms
Drosophila melanogaster
Model organism - the ‘vinegar fly’
Yellow brown, with black rings across the abdomen and red eyes
Deer Fly Life Cycle
Eggs - single mass of 100-800 eggs
Larvae - from 6-13 development stages
Pupa - completed in 1-3 weeks
Adult - emerge in late spring-summer, females feed on blood
Holometabolous
Describes insect development which includes four life stages
Larval Stage
Feeding stage
Predominately apodous (legless) larvae (maggots)
– E.g. hoverflies with rat tailed maggots
– Exceptions include Rhagionidae
Types of dipterous larvae
Midge - distinctive head capsule, prehensile antennae that catch prey
Mosquito - distinct head capsule
Horse fly - hemicephalous head, more reduced head and mouth parts
House fly (maggots) - no head, cephalopharyngeal skeleton
Pupal stage
Reorganisaiton stage
Complete metamorphosis that occurs between the larval and adult stages
Some also have cocoons
Diptera Pupae/Puparia
Diagnostic feature that splits higher and lower flies
Crane fly - primitive, can see wing development
Mosquito - active during pupal stage
Robber fly
Blow fly - puparium
Three diagnostic features of adults
Wings - one pair/two wings. Halteres - hind wings with an unknown function.
Halteres
Reduced hind wings of diptera
May be involved in balance or steering
Mesothorax
Middle segment of the thorax
Has become enlarged to contain the enormous flight muscles, the pro and metathroax are correspondingly reduced
Diptera Head
Frons
Ocellus - simple eyes, no colour, used for looking at the horizon
Gena - face
Occiput - bristles behind the head
Chaetotaxy
Arrangement of bristles
Proclinate
Bristles directed forwards
Reclinate
Bristles directed backwards
Inclinate
Bristles directed inwards
Lateroclinate
Bristles directed outwards
Three basic parts of antennae
The basal segment or scape
The second segment or pedicel
The third segment or flagellum, which contains carrying number of flagellomeres
Sexual diphorism in adults
Eyes spilt in females, joined in males
Antennae in males are bushy
Modifications to mouthparts
Some families have mouthparts elongated into a rostrum, like Tipulidae
Colocephaly
Head is disproportionately small
Streblidae
Flies with very reduced eyes
Only 7 eye facets
Lives on bats
Eye bands/patterns
Not due to colour or pigment, caused by light refraction
‘Nipples’ cause light waves to refract
Mouthparts of Diptera
Labrum - upper lip
Hypopharynx - assists with swallowing
Labium - lower lip
Mostly missing mandibles and/or maxillae
Principle piercing structure of Diptera
The labium, which terminates in a pair of hard plates (labella), which are armed with teeth
Sponging/Lapping Mouthparts
Labium terminates in a pair of large, soft, oval lobes (labella) which have numerous grooves (pseudotrachea) which sponge-up the liquid food (may first have been liquified by salivary secretions of fly)
Wings and flight
- One pair (hence Diptera)
- Well developed mesothorax contains especially large flight muscles. Midges can reach 1000 wing beats/second
- Flight involves complex aerodynamics of lift, thrust, and attitude control.
- Sense organs preserving stability include compound eyes, mechanoreceptors on antennae etc. while halteres act like gyroscopes registering deviations
6 primary veins of Diptera
Costa Subcosta Radius Media Cubitus Anal
Aedeagus
The penis
Gonostylus
Apical part of the phallus with a stocky basal part and a long rod like in/articulated apical section
Gonocoxite
Chitinized skeletal structure
