Entomology

Front 1

Compare external structure of honey bees to other common insects eg. grasshopper. How are they similar/different?

Back 1

Similarities: 3 body parts, 2 pairs of wings (except in Diptera) six pairs of legs, legs have same basic structure, head similar in shape.
Differences: Mouthparts differ, (bees lap nectar, grasshoppers chew) pollen baskets on hind legs to store pollen, hairy body to help catch pollen, short fillamentous antenna, compound eyes

Front 2

What are the physical characteristics and developmental stages shared by all holometabolous orders that make them different from other insects?  Name and describe as many of these differences as you can -- both, for adults and for immatures.

 

Back 2

Holometabolous: Complete metamorphosis
Larval, pupal and adult stages look completely different. Diets and activities differ between forms. Each form occupies a different ecological niche
Hemimetabolous: Partial metamorphosis  where early instars are similar. Last instar has wing buds. Adult looks similar to last instar except with wings
Ametabolous: No difference in external appearance of hatchling to adult. Adult does not have wings

Front 3

Discuss and contrast insect defence by mimicry and insect defence by hiding

 

Back 3

Defence by Mimicry: Defend themselves by looking like other animals. A good example is the Viceroy butterfly and the Monarch butterfly. The Monarch is poisonous, the Viceroy likes to pretend it is.
Hiding: Insects that employ camouflage to blend into their background. Masquerading as an object such as a bird dropping or a leaf
eg.  Stick insects

Front 4

Identify and discuss some of the similarities between ants and termites

 

Back 4

Similarities:Trophallaxis for social regulation, Pheromones to control caste development and behaviour, Similar nest structure and complexity.

Front 5

Identify and discuss some of the differences between ants and termites

Back 5

Ants: Cast determination = nutrition
Workers all female
Males mate once and die
Fertilisation occurs during nupital flight
Termites: Cast determination = pheromones/gender
Workers male and female
King stays with queen after nupital flight for a happy ever after
Fertilisation occurs after nupital flight

Front 6

Discuss and describe Subsociality and Eusociality in social insects

 

Back 6

Sociality in insects comes in two forms; Subsociality: Insects with less strongly developed social habits such as provisioning for young, and, Eusociality: Or ‘True Sociality’ where insects co-operate to form highly complex, caste driven nest systems.
Subsocial: Post-oviposition/post-hatching parental care, with or without nest construction, some level of provisioning for young, occasional communal nesting , no overlap of generations
Eusocial: Labour divided by caste system
Caste system includes non-reproductives
Reproduction restricted to queens
Colony members all tend young
Overlap of generations

Front 7

It is thought that insects co-evolved with plants. Give an example of mutualism and pollination and describe why this is important

 

Back 7

Pollination and mutualism are not mutually exclusive, however there is one insect life cycle that represents both. The Fig wasp life cycle allows the fig flower to be pollinated, and the wasp to reproduce at the same time. Both rely solely on the other for reproduction. The process occurs as follows:

 

Front 8

Name important hormones in insect development

Back 8

Ecdysteroid – promotes molting
Juvenile hormones – controls growth, metamorphosis
Neurohormones – regulates many aspects of insect development, homeostasis, metabolism, reproduction

 

Front 9

What are galls and what forms do they come in?

Back 9

Galls are growths on a plant usually activated through insect intervention. 
Includes:

Filz galls - hairy outgrowths on surface, insect within
Roll galls - insect covered by leaves, stems & shoots
Pouch galls - simple bulge on one side of leaf
Rosette gall - insect stimulates apical thickening, hyperactivity of apical meristem, looks like rosette

Front 10

Describes types of phytophagous herbivory

Back 10

Leaf eaters - chewers, miners
Sap suckers- either macerate flush or use stylet
Boring - similar to leaf mining, allows larger insects to participate.
Wood feeding - inc. wood boring species living in trees without fungi. beetles, weevils, cossid moths
fruit feeding - feeding on fleshy fruits like guava, loquat

Front 11

Whats the difference between direct flight and indirect flight

Back 11

Direct flight- wings pivot up and down around single pivot point. Muscles connected directly to wing contract to bring it up and down.
Indirect flight – dorsoventral contraction forces thoracic box down, pivots wings up. Longitudinal muscle contraction forces thorax back up, lowers wings. Diptera

 

Front 12

How can the diet of an insect be determined?

Back 12

-Direct observation
- Gut content analysis
-Morphological assumption
- Stable isotope analysis

 

Front 13

Name some ways plants have adapted to deter heriborous insects

Back 13

Mechanical
- coat leaf surfaces with indigestible waxes
- sharp spines, lignified tissues, plant waxes
- development of sharp spines
- hairs, sticky coating on young leaves
Chemical
- toxins – pyrethrum, ricin
-antifeedants / feeding inhibitors
-repellents

 

Front 14

Why are Coleoptera (beetles) the most successful animals?

Back 14

Elytra - hindwings fold under elytra and covers spiracles, reducing water loss. Also very compact as they house the coxa in a cavity. Allows them to cocupy all sorts of habitats

Front 15

What is myiasis?

Back 15

Infestation of living vertebrate tissue with the maggots of a fly which eats otherwise healthy tissue.

Front 16

What three traits define eusociality?

Back 16

1. Division of labour with a caste system involving sterile or non-reproductive individuals assisting those which reproduce
2. Cooperation among colony members in tending the young
3. Overlap of generations capable of contributing to colony functioning.

 

Front 17

How do parasites overcome their hosts immune response?

Back 17

- Avoidance of haemolymph response
- Evasion: molecular mimicry, cloaking, rapid development
- Destruction: weakening hosts immune defence
- Suppression: immune response suppressed by parasitoid viruses
- Subversion: development occurs anyway despite host response

 

Front 18

Explain the different types of host use by parasitoids

Back 18

Polyembrony – single egg divides multiple times to produce up to 3000 offspring
Superparasitism: a host is parasitised by more than one of the same species of parasite
Multiparasitism: a host receives eggs of more than one species of parasitoid. More common than superparasitism  as it is probably more difficult to detect if host has been parasitized by other species.
Hyperparasitism – type of multiparasitism where a secondary parasitoid develops at expense of primary parasitoid.

 

Front 19

Difference between Idiobiont and Konobiont parasitoids?

Back 19

Idiobiont – kills or paralyses host so it does not develop further. Larvae typically undergo rapid development (finite resources) almost invariably ectoparasitoids.
Konobiont – host undergoes further development following oviposition. Parasitoid usually lays eggs in young stage of host (egg, early larva)  parasitoid development can be delayed until host big enough to  sustain it. Host regulation is a key feature of konobionts.

 

Front 20

Define aposematism and deimatic colouring and the differences between them.

Back 20

Aposematism - Warning colouring, used by insects to deter predators by warning that they are poisonous or toxic.
Deimatic colouring: startle colouring. Animal hides bright colours or prominent eyespots under cryptic overlayer until threatened, where it abruptly displays in an attempt to startle.

Front 21

What important roles do detritivores & scavengers play?

Back 21

Soil ecosystems: Responsible for structuring & turning over soil
Leaf litter: Contribute to litter breakdown
Wood: Have help to digest wood. Employ gut symbionts, cellulases or fungi to help break down the cellulose.
Dung: assists with removal of dung & aeration of soil
Carrion: successional groups of insects break down vertebrate tissue

 

Front 22

Difference between Batesian mimicry and Mullerian mimicry?

Back 22

Batesian mimicry – mimicking the warning signals of a harmful species to a common predator. Eg. Monarch poisonous, Viceroy nearly identical but palatable.
Mullerian mimicry – both model and mimic share warning signal and protection. Thus both species share the burden of enlightening predators of their harmful properties. Both parties benefit.

 

Front 23

Similarity through a. convergent evolution or b. common ancestry

Back 23

a) homoplasy
b) homology

Front 24

Why might we collect insects?

Back 24

1. to determine species present
2. use for taxonomic studies and to determine species limits
3. observe change or lack thereof

Front 25

5 insects with the most number of described species?

Back 25

    Coleoptera (350,000)
    Lepidoptera (160,000)
  Diptera (150,000)
  Hymenoptera (115,000)
    Hemiptera (100,000)

 

Front 26

Difference between entognatha and ectognatha?

Back 26

Entognatha - ametabolous, wingless, jaws retracted in head. Collembola, diplura, protura.
Ectognatha: 28 orders. "insecta". moutparts outside body

Front 27

What adaptations have cave-dwelling insects developed?

Back 27

Vestigial / absent eyes, reduced pigmentation, small body, elongated legs, loss of wings.

Front 28

What behaviours do insects use to attract mates?

Back 28

Courtship – Bringing Sexes together
- Signals like sounds, pheromones, light
- Swarming behavior
-Sex pheromones, usually produced by females. Males pick up with antennae
Courtship  Displays
- Visual displays
-Rubbing, stroking, acoustic courtship

 

Front 29

Discuss fleas as a vector for disease.

Back 29

Fleas are one of many vectors for disease. Parasitic fleas may specialize on specific mammals, but can usually use other mammals as hosts, leaving humans susceptible to parasitism. Viruses and bacterial pathogens can both be spread, including flea-borne typhus, bartonella and the bubonic plague. The bubonic plague ravaged empires throughout history when fleas fed on the blood of infected rats, contracting y.pestis. When their rat hosts die, they seek out other hosts, where y. pestis could propagate in the gut and spread.