Insects Flashcards

Question

Insects Through Time | Jurassic

Answer 1

- 150--200mya | - modern orders but now extinct families

Answer 2

- 150-64mya - feathered dinosaurs - Neuroptera and Hymenoptera - insects act as pollinators - coevolution of insects with flowering plants

Answer 3

- 55-35mya - Baltic amber forest - mammals - diatryma (birds) - hemipteran - butterflies

Answer 4

crustaceans

Answer 5

- fossilised plant resin - best known from Baltic area - preserves small animals - can infer ecological interaction - -parasite on organisms - -organisms trapped in close proximity to each other

Answer 6

- dominate terrestrial and freshwater biodiversity - can transmit diseases - some feed on animals - pollination - Drosophilia (fruit fly) is THE model animal organism

Answer 7

- more than 50% of all described species are insects - it is estimated that only 1/5 of insects have been describes - most are 2-3mm in length

Answer 8

- jointed limbs - exoskeleton made up of plates - intersegmental membrane that attaches plates together is what allows joints to bend

Answer 9

- two pairs of wings on second and third thorax segments - wings are probably modified gills, which were modified second leg branches - some of the same genes are involved in both larval wing and larval gill development

Answer 10

- have to moult or exoskeleton puts a limit on how big they can grow - immediately after moulting, lose water more rapidly, unable to fly, find it difficult to walk - a less rigid exoskeleton allows insects e.g. maggots to grow in between moults - in primitive insects, moults only produce larger almost identical copies

Answer 11

- body plans based on repeating units - basic body plan: - -head - -3 segment thorax - -abdominal segments

Answer 12

- originally 6 segments, now fused together - specialised for feeding and sensory detection - antenna - eyes - 'teeth' outside bdy

Answer 13

- Mandibles - jaws - Maxilla - inner branch, small set of jaws and sensory palps - Labium - lower lip, like two maxilla fused together, used as a spoon to push food into the mouth, palps - Labrum - upper lip, like labium but without palps

Answer 14

- 'Brain' - collection of ganglia fused from original brain segments - ventral nerve cord - ganglion (concentration of nerve cells) in each segment

Answer 15

- specialised for locomotion - lots of muscle - 3 pairs of legs - wings

Answer 16

- specialised for metabolism and reproduction - appendages mostly lost - at the tail end, several segments are fused together and specialised for reproduction

Answer 17

- extreme metamorphosis is seen in advanced insects | - maggot -> larger larva -> pupa -> fly

Answer 18

- separate males ad females - males and females can look the same or different - not all insects are sexually dimorphic

Answer 19

- more O2 in the atmosphere allow insects to grow bigger due to limitations in their respiratory systems - spiracle - external opening to the respiratory system - pump bodies to squeeze air sacs approximating breathing - air travels down main trachea and then along tracheal branches to tracheoles which get narrower and narrower until they can enter cells - very efficient over distances less than 1mm but gets less efficient the bigger the insect is

Answer 20

- open blood stream - 'heart' - tube lined with muscles that can contract - has valves to direct blood flow towards the brain - aorta carries blood from heart to brain - haemocoel - body cavity, organs hang in the haemocoel which fills with blood - oxygen etc. moves by diffusion through haemocoel back to heart - almost no veins or arteries

Answer 21

- scavengers feeding on decayed plants and animals or detritus - chewing evolved before sucking - dead plants eaten before live plants as living plants are often well defended but nutrient poor

Answer 22

-stage where most growth happens so where most biomass is removed from environment (most damage done)

Answer 23

larvae and adults eat similar food

Answer 24

larae and adults eat different food

Answer 25

Labrum - upper lip Labium - lower lip (palps) Maxilla - palps Mandible - jaw

Answer 26

- usually have large mandibles | - legs can be used instead of jaw so insects don't have to have large mandibles to be predators

Answer 27

- mouthparts at the end of a long proboscis - chew deeply into plants - lay eggs inside hole in plant

Answer 28

- phloem and xylem - individual cell contents - insides of prey - blood

Answer 29

- mandibles and part of maxillae modified to form stylets - stylets are cartlidge rods that can be stabbed into prey - rest of maxillae form inner/maxillary stylets - there is a salivary canal between the inner stylets - saliva is pumped down a ventral channel and digested food is sucked up the dorsal channel - sensory palps lost - labium and labrum enlarged to protect stylets - Cibarial pump - vaccum pump, muscles contract creating a partial vaccum inside the mouth drawing liquid up

Answer 30

-loop in gut -food passes around the loop -but water is able to skip the loop by crossing the small gap between the beginning and end of the gut -

Answer 31

- liquid food is very high in water content - in order to ingest enough nutrients, insects end up taking in way to much water - this is bad for many reasons e.g. enzymes don't work as well at low substrate concentration - filter chamber allows excess water to be quickly passed out of the body

Answer 32

- sweat - cuckoo spit - soap added to water as it leaves the body causing it to froth and insect can hide in it - honeydew - phloem feeding insects also ingest excess sugar so release water and sugar, ants eat honeydew, and ants distract parasitic wasps from insects

Answer 33

``` Caterpillars -primitive chewing type with mandibles and maxillae Butterflies -mandibles lost -maxillae form short proboscis ```

Answer 34

-easier to reach than phloem, xylem or blood as the skin doesn't have to be pierced

Answer 35

- proboscis elongated - evolution of plants to have longer flower led to coevolution of the hawk moth - proboscis curls up when not being used to protect it - this happens when there is no pressure inside the tube, it automatically curls

Answer 36

- spiky legs to catch and kill prey | - sucks liquid contents of prey

Answer 37

- feed on blood - relatively specialist, feed on specific species - abdomen fills with blood - presence of blood in abdomen required for egg development - lays eggs in/on water - transmit many diseases - females only feed on blood

Answer 38

- feed in liquid - filter feeders - complex set if spines/hairs on mouthparts - mouthparts move and hairs draw water across the head - other mouthparts act as sieves and others scrape the collected food into the mouth

Answer 39

- doesn't feed - is alive - can swim - has eyes and respiratory tube

Answer 40

- many branches on antenna | - increase in surface area to detect female ferimones

Answer 41

- maxillary and mandibulary mouthparts both for cutting - stylets stick into prey - labium protects stylets when not feeding - hypopharynx = straw