Insect Anatomy= mouth parts and antennae

Question 1

what is meant by an insect tagmata

Answer 1

a morphologically distinct region, typically comprising of several adjoining segments of insects

Question 2

what is the insect tagmata comprised of

Answer 2

1) Head = Prosoma
2) Thorax= Mesosoma
3) Abdomen= Metasoma

Question 3

what does the head part of the insect tagmata include

Answer 3

• mouthparts
• antennae
• compound eye
• ocelli

Question 4

outline the mouthparts of insects on the head of the tagmata

Answer 4

a modifed, paired feeding appendage which is also used to capture and manipulate food

Question 5

what are the mouthparts of insects made up of

Answer 5

1) labrum
2) Mandible x 2
3) Maxilla x2
4) Labium

Question 6

what is the labrum which is found in the mouthparts of insects heads

Answer 6

a plate (sclerite) which serves as an upper lip in insects with chewing mouthparts= helps to pull food into the mouth

Question 7

outline what insect manibles are found in the mouthparts on the heads of insects

Answer 7

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

Question 8

what are the different roles insect mandibles are used for

Answer 8

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

Question 9

outline what the maxillae is in the mouthparts of insects found on the head

Answer 9

a second pair of feeding appendages used for the handling of food and sensing
= work in a similar way to manibles

Question 10

what are the different parts of the maxilla

Answer 10

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

Question 11

outline the role of the labium in the mouthparts of insects found on the head

Answer 11

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

Question 12

what are the different parts of the labium

Answer 12

1) submentum
2) mentum
3) prementum
4) Glossa
5) Palp
6) paraglossa

Question 13

what is a hypopharynx

Answer 13

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

Question 14

what are the three different positions that insect mouthparts can be articulated

Answer 14

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

Question 15

what are the two main functional groups of mouthparts which vary among insects of different orders

Answer 15

1) mandibulate
2) haustellate

Question 16

outline Haustellate mouthparts

Answer 16

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

Question 17

outline the use of mandibulate mouthparts for plant chewing

Answer 17

• 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

Question 18

outline how mandibulates are adapted for predatory chewing mouthparts

Answer 18

primitive mouthparts directed forwards
- mandibles long and curved with sharp tips for impaling
e.g. ground beetle

Question 19

outline how insect mouthparts can be modified for nectar/pollen collection

Answer 19

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

Question 20

outline how mouthparts can be adapted to be sponging mouthparts

Answer 20

• 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

Question 21

outline how mouthparts can be adapted to become siphoning mouthparts

Answer 21

• haustellate mouthparts
• proboscis (modified maxillary galeae) uncoils and extends sucking nectar into mouth or oral cavity

Question 22

outline how mouthparts can be adapted to become piercing/sucking mouthparts

Answer 22

• 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

Question 23

outline mosquito mouthparts

Answer 23

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

Question 24

what are antennae

Answer 24

paired sensory appendages on the head of insects

Question 25

outline the roles of the antennae

Answer 25

• located between or below the compound eyes
• provide greater surface area for sensory receptors
• some may detect sound vibrations, wind speed and humidity

Question 26

outline the antennal structure

Question 27

outline antennal morphology

Answer 27

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

Question 28

what are different anteanne types

Answer 28

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