Insect Anatomy= mouth parts and antennae Flashcards
what is meant by an insect tagmata
a morphologically distinct region, typically comprising of several adjoining segments of insects
what is the insect tagmata comprised of
1) Head = Prosoma
2) Thorax= Mesosoma
3) Abdomen= Metasoma
what does the head part of the insect tagmata include
- mouthparts
- antennae
- compound eye
- ocelli
outline the mouthparts of insects on the head of the tagmata
a modifed, paired feeding appendage which is also used to capture and manipulate food
what are the mouthparts of insects made up of
1) labrum
2) Mandible x 2
3) Maxilla x2
4) Labium
what is the labrum which is found in the mouthparts of insects heads
a plate (sclerite) which serves as an upper lip in insects with chewing mouthparts= helps to pull food into the mouth
outline what insect manibles are found in the mouthparts on the heads of insects
paired appendages of 4th body segments become the 1st pair of mouthparts
= used to chew/cut/ tear food, carry things, fight, mould wax and filter feed
= move side to side
what are the different roles insect mandibles are used for
1) eating tough food = leaves, wood, cereal grain e.g. termites, grain beetles and ants
2) defence and competition = defend territories e.g. ants, or compete for females e.g. stag beetles
= can incorporate metals such as zinc or manganese into the cuticle of mouthparts
outline what the maxillae is in the mouthparts of insects found on the head
a second pair of feeding appendages used for the handling of food and sensing
= work in a similar way to manibles
what are the different parts of the maxilla
1) cardo= found at top
2) stipes = makes ip majority
3) subgalea = found to the right of the stipes
4) maxillary palm= long stick like part
5) lacinia = to the right of stipes below subgalea
6) galea = found at the bottom of maxilla
outline the role of the labium in the mouthparts of insects found on the head
fused 3rd pair of feeding appendages that close the mouth below or behind
= analogous to lower lip
= evoloved from paired maxillae-like structures fused along centre line
what are the different parts of the labium
1) submentum
2) mentum
3) prementum
4) Glossa
5) Palp
6) paraglossa
what is a hypopharynx
a membranous tongue which projects fowards from the back of the pre-oral cavity
= contains salivary ducts at the base
= highly modified in diptera and hemiptera as the main feeding organ
= combines with the rest of the mouthparts to fom a stylet
what are the three different positions that insect mouthparts can be articulated
1) prognathous = head positioned vertically aligned with body e.g. coleoptera
2) hypognathous = head aligned horizontally adjacent to body e.g. orthroptera (grass hoppers etc)
3) opisthognathous = positioned diagonally e.g. hemiptera
what are the two main functional groups of mouthparts which vary among insects of different orders
1) mandibulate
2) haustellate
outline Haustellate mouthparts
mouthparts used for sucking liquids which can be further classified by the presence of stylets which include
- piercing-sucking
- sponging
- siphoning
stylet = need-like porjections to penetrate plant/animal tissue
stylets and feeding tubes form modified mandibles. maxilla and hypopharynx mouth parts
outline the use of mandibulate mouthparts for plant chewing
- primitve mouthparts directed downwards
- two powerful mandibles, usually lined with teeth work sideways
- chewing insects have two lips
1) upper lips (lubrum) is a flap which hangs down over mouthparts and covers mouth from front
2) lower lip (labium) covers mouth from behind
outline how mandibulates are adapted for predatory chewing mouthparts
primitive mouthparts directed forwards
- mandibles long and curved with sharp tips for impaling
e.g. ground beetle
outline how insect mouthparts can be modified for nectar/pollen collection
1) utilise liquids and solids
2) proboscis (elongated sucking mouthparts, usually a modified labium) for lapping liquids and for exchange with other bees
3) mandibles used to chew wood, manipulate wax, clean and bite other bees/pests
outline how mouthparts can be adapted to be sponging mouthparts
- haustellate mouthparts where the proboscis is lowered and saliavry secretions are pumped onto the food
- dissolved food moves into the pseudotrachae (sponge) and is ingested
- sharp teeth on pseudotracheae to rasp flesh and draw up blood
- labellum functions as sponge like organ to sop up liquids
outline how mouthparts can be adapted to become siphoning mouthparts
- haustellate mouthparts
- proboscis (modified maxillary galeae) uncoils and extends sucking nectar into mouth or oral cavity
outline how mouthparts can be adapted to become piercing/sucking mouthparts
- haustellate mouthparts modified for fluid feeding
- mandibles and maxillae formed into stylets and are enclosed by labium
- once stylets penetrate a secretion is injected
1) blood sucking = anaesthetic and anticoagulant
2) predacious = enzymes and toxins
outline mosquito mouthparts
1) haustellate mouthparts of a female mosquito are highly modified for piercing skin and sucking blood
- males have similar mouthparts but feed on nectar
- labium slides back towards head
- mandibles and maxillae now exposed and pierce the skin
- sensory organs on tips confirm hosts
what are antennae
paired sensory appendages on the head of insects
outline the roles of the antennae
- located between or below the compound eyes
- provide greater surface area for sensory receptors
- some may detect sound vibrations, wind speed and humidity
outline the antennal structure
outline antennal morphology
used in taxonomic classification
- males usually have more elaborate antennae
- greater surface area of antennae = more dilute scents can be detected
- male insects with feathery antennae e.g. moths = more sensative than filamentous ones of crickets and cockroches
what are different anteanne types
1) Geniculate = elbowed e.g. bees and ants
2) Lamellate = nested plates e.g. scarab beetles
3) pectinate = comb like e.g. male glow worms
4) plumose = brush-like/feathery e.g. moths
5) clavate = gradually clubbed e.g. carrion beetles
6) capitate= abruptly clubbed e.g. butterflies
7) setaceous = bristle like e.g. dragonflies
8) filiform = threadlike e.g. cockroaches
9) moniliform = beadlike e.g. termites
10) serrate = saw toothed e.g. click beetles
11) aristate = pouch like with bristles e.g. houselfy
