Arthropods Flashcards

Question

What is the most obvious difference between one insects ears to another?

Answer 1

Nearby sound drives fast moving air molecules into the hairs on the mosquitos antenna causing antennal shaft to vibrate These vibrations travel down antennae to Johnstons organ(packed with 15000 motion sensitive receptors tuned to hear the sound of another mosquito in flight) Males use this to locate mates These receptors also act to amplify vibrations in the antenna

Answer 2

A collection of sensory cells found in the pedicel of the antennae of insects Johnstons organ detects movement in The flagellum

Answer 3

-Katydid ears are highly sophisticated -They have broad band hearing frequency analysis -The ears, one per foreleg, each have two eardrums, which vibrate in response to sound -These vibrations cause the tympanal plate to rock up and down- transmitting the vibrations to the fluid in the auditory vesicle. -The result is tsunami like travelling wave which rolls over the Christa acustica where a line of sensor cells pick out different frequencies and relay info to the brain - a second internal channel transfers sound vibrations through the thorax through a tracheal tube that runs from the acoustic spiracle(pore) to the inner surface of the tympanum. - **thus the katydid therefore receives the same signal twice** once internally and once externally - difference between the two helps determine the source of the sound

Answer 4

It means toothed and refers to the sharp teeth om the jaws of dragon and damselflies Their legs are armed with immobile bristles which together form a basket like trap in which they scoop up prey as they dart through the air

Answer 5

This happens because the bodies colours are produced by epidermal pigments which de nature after death The wing colour is a result from light being reflected off the surface in a particular way depending on the micro texturing

Answer 6

-Before mating male bends his abdomen forwards in order to transfer sperm from the tip of the abdomen to a pouch under the third abdominal segment -The male then flies of in search of a mate - once a mate is found the male has claspers at the rear of the abdomen used to hold the female firmly behind het head. - female then bends her abdomen forward until the tip touches the males sperm pouch - sperm transferred while at rest and they are often seen flying around in tandem

Answer 7

-The male why try to maintain a hold on the female while she lays her eggs, or may hover above her to prevent other males from mating with her -Dragon and damselflies are seen skimming over the water briefly touching, laying their eggs which then drift down to the bottom of the pool -Females may also drill a hole into the stems of leaves and plants with the sharp projecting ovipositor at the tip of the abdomen. - she will lay 5-6 in a row and then move to the next plant

Answer 8

They can stay dormant across the whole winter or may hatch within two to three weeks after being laid

Answer 9

-Nymphs are aquatic -Vary in appearance: damselflies=slender, dragonflies= robust and squat - all have well developed legs and signs of wing development as flaps on thorax - nymph’s cast their skin 11-15 times in the coarse of their development - some reach full size in a few weeks whistle others take a year or longer

Answer 10

-The lower lip of the mouth(labium) has been modified into a hinged extendable arm with a scoop at the end called the mask -Normally held flat against the head, this structure gets rapidly shot out to seize their prey that are swimming or drifting past.

Answer 11

-They generally have 3 leaf like gills(caudal lamellae) projecting from the posterior end of the body, used for respiration and movement

Answer 12

-The nymph climbs up a stick or plant stem reaching above the water level. - hangs by the claws of its legs and a split appears along the insects back - adult emergence leaving behind old skin. - wings unfold and harden - adult flies of and life cycle starts over

Answer 13

-Neither worms nor flies , but in fact soft bodied beetles from the order coleoptera

Answer 14

Generally speaking when you see a “firefly” you are looking at a male and “glow worms” are a female

Answer 15

-Underneath the tip of the abdomen has a ‘mirror’ consisting of air filled cells that are highly reflective. -The actual light is triggered by nerve endings initiating a chemical enzyme reaction generating light

Answer 16

**Luciferin**- luminous substance contained in the relative segment **luciferase** oxidising enzyme in the blood

Answer 17

To help males find potential mates and for certain species to act as a attractor of potential prey

Answer 18

-In the larvae stage they feed mainly on snails and slugs, paralysing their prey before sucking them empty - adults do not eat except for some adult female they will eat males of a similar species

Answer 19

The flickering is actually a form of aposematic coloration showing us that they are heavily poisonous when ingested

Answer 20

Has a holometabolic life cycle consisting of egg,larvae, pups and adult They typically live for about a year

Answer 21

Look similar to dragonflies in their adult forms Large and clubbed antennae Most active at night with clumsy flight patterns

Answer 22

-They burrow backwards into loose sand which they flip out with their flat heads to make funnel traps -They then lie and wait at the bottom of the pit just beneath the sand - once an insect is detected at the top of the pit sand is through over in so it falls into the pit by using their flat head - if “lucky” ant lions can reach full maturity within a couple of weeks or “unlucky” need a year or more

Answer 23

They grab their prey with their large pincers taking them below the surface, injecting it with enzymes and then sucking out the digested body using the same hollow pincers in reverse -They do this because ants have a very keen sense of smell, and thus antlion larvae can not afford to give if any trace of oder so both mouth and anus are sealed. - waste products accumulate in the sealed rectum and gets left behind when the skin is shed at this point a new hole is made

Answer 24

Term arachnid is used to describe a class of arthropods which include scorpions, spiders, solifuges, whipscorpions , ticks and mites and certain 8 legged invertebrates

Answer 25

Divided into two parts: **anterior** - cephalothorax, containing sense organs, mouthparts and limbs in pairs- first pair *chelicerae* may for pincers or venom fangs, second pair known as *pedipalps* may serve as pincers, feelers or legs Other pairs generally four used for walking **Posterior** abdomen bears the genital opening and other structures. Usually equipped with modified gills called book lungs

Answer 26

*Salticidae*(jumping spiders)

Answer 27

**Neurotoxic**- black button spider - brown button spider **cytotoxic**- violin spider - sac spider - six eyed crab spider

Answer 28

Mygalomorphs and Araneomorphs

Answer 29

Bothuridae Buthidae Homuridae Scorpionidae

Answer 30

-**Palps** of spiders are uniquely modified as reproductive organs - **epigynum** of female is also constructed in a unique manner as to only accept configuration with palp of male of the same species - immature spiders sexual organs are non functional and only become active after final ecdysis( shedding or moulting of outerlayer of skin) when adult maturity is reached - male spiders single aim in life is to find a mate

Answer 31

-Male charges his palps with seminal fluid before mating begins - genital pore of male and female found on underside of abdomen between book lungs - to transfer sperm from genital pore to palp, male constructs a small triangular square web just above the ground while standing above the web deposits a drop of sperm onto center of the web and then presses his pulp into the sperm - drawing up the fluid via enlarged embolus of the pulp - when male finds female he must convince her that he is from the same species and that he wants to mate or she will kill him

Answer 32

- The males perform a dance to convince the female to mate with them and not kill them - wolf spider waves his pedipalps up and down in rhythmic movement while tapping the front front pair of legs on the ground. - slowly moves towards the female waiting for a signal that she is ready to accept him and not attack him - sometimes there is leg rubbing and touching before mating takes place

Answer 33

-Have very brightly coloured hairs on their pedipalps, -waving these and their first pair if legs raised above the head - moves around female in an arc, waiting for her to accept him

Answer 34

-Via leg tickling before full contact is made - in web building spiders male comes to edge of the web plucking or tapping on the silk strands to announce his presence

Answer 35

-Male moved towards the female web and tugs on a strand of the web on which she is sitting - he then drops down on his own drag line to avoid her initial attack - this process gets repeated until the female is convinced that he is a prospective mate and not a meal - male then spins a mating thread onto which he lures the female where to mate after which he makes a hasty retreat to avoid being eaten

Answer 36

-Between a few seconds and a number of hours(depending on species) - in some species courtship long mating short - in others courtship short mating uo to 7 hours

Answer 37

-She may hold the sperm in her spermathecae( a receptacle in which sperm is stored after mating) - she only uses the amount she needs to fertilise the eggs that she lays at one time - able to produce large number of egg-sacs full of fertile eggs after only having mated once

Answer 38

**Araneomorphs** can shed their skin and retain viable sperm **Mygalomorphs** loose the sperm and need to mate again in order to fertilise eggs

Answer 39

A year in most species Up to 18 months in some jumping and wolf spiders Primitive spiders(Mygalomorphs) like a baboon spider reach maturity only at 12 years and can live for another 5 or more years after that

Answer 40

-Some spiders such as Lynx and rain spiders tend to stay with the egg sac and guard it until the young hatch - nursery web spiders provide a nursery in which spiderlings live until they can fend for themselves - wolf spiders carry their young around on their backs until they are ready to go their own way

Answer 41

-When spiders emerge from the egg they are identical to adult. - grow rapidly via skin shedding(ecdysis) - when old skin is shed there is rapid growth until skin hardens and prevents growth. - have to wait for next ecdysis to grow again - spiders at a young age disperse via **ballooning** - climbing to a high point, facing into the wind and emitting strands of silk like threads from spinnerets.

Answer 42

-Dew drop spiders found in the large webs of other spiders(golden orb spiders) - dew drop spiders scavenge off of food in the orb spiders web - dew drop spiders moves in on caught prey, attaching a web line and cutting it away from the main web, after feeding on the scavenged meal head back to main web - orb spider usually unaware of kleptoparasite

Answer 43

-These arachnids are know by a variety of different names, red romans, wind spiders, hunting spiders - are aggressive predators often seen in rainy season dashing about looking for food - lack venom glands but do have powerful chelicerae. - pedipalps slender and look like extra pair of legs - strong jaws for defence and to catch their prey, scissor like action cuts prey up and then juices are sucked out( feed on insects, baboon spiders, small birds, snakes and lizards

Answer 44

-body covered in sensory hairs - organs of taste, smell and hearing are present on the feet and mouthparts - other sense organs are concentrated in special structures at the base of the last legs -have a series of special hairs and spines, allowing them to run rapidly over loose sand

Answer 45

Some hunt by day and have dark markings over body and legs and tend to be smaller than nocturnal species that are yellow to brown in colour

Answer 46

Mature Males have a species specific shape of horn like extensions on the upper jaw that females and juveniles lack

Answer 47

-They are solitary and live in shallow retreats scraped out under rocks and logs. - they make the retreat by loosening the soil with their jaws and pushing sand backwards with their feet. - after the rainy season female lays about 20 eggs and guard the egg case until the young hatch - after they moult they leave the mother and live on their own

Answer 48

They can live up to a year or more depending on the species

Answer 49

-They are not true spiders as they do not have spinning organs at the end of the abdomen - their name originates from the whip like movements of the first pair of legs

Answer 50

No, they are absolutely harmless

Answer 51

They can be found under tree bark, in rock crevices and beneath fallen trees, where soul is moist and rich in decomposing leaf litter.

Answer 52

-They pretend to be dead and rely on their mottled yellow brown colouring to blend into the background. -to escape they use rapid burst of speed forwards and backwards

Answer 53

-They usually hunt at night when it is cool but do move in the day when conditions are cool - the flexible pair of legs act as feelers and mouthparts are used as pincers to spear small insects for food

Answer 54

-They take 2 years to reach maturity and can live for several years after that - at the start of the rainy season female lays about 20 eggs in an egg case that remains attached to the lower surface of her abdomen until the young hatch - the babies cling to her back for about two weeks before they moult and move off on their own

Answer 55

- have pincers - have a tail with a sting at the end - having pectines, which are comb like structures on the underside of the body

Answer 56

-Males actively seek out females for mating - females give of a scent trail via pheromones, males sense this through their pectins - when mate is found male signals his intentions via pincer tapping, tail wagging and juddering of the whole body which sends vibrations through the ground - male will only approach female when a positive response is made

Answer 57

-Mating takes place via a complex dance where scorpions are head on with eachother - male holding female pincers stepping back and forth - males of most species have modified pincers for gripping females - once male has good grip on female he moves around making use of his pectines on his underside to find a suitable surface to deposit spermatophore - dance can last for 30 min and move 25m - when male has deposited spermatophore on the ground he moves the female that the hooks on the small package of sperm catch onto the females genital opening - this is accomplished by the female opening her opercula and either arching her body over the spermatophore or by the male picking her up and placing het ontop of it - the females body weight bends the spermatophore and this releases the sperm. -Female stays motionless for a short period of time -after this they break away from one another and sometimes club and sting each other females even try to kill males

Answer 58

Varys from species to species but in general between a few moths to 18 months(longest period of any arachnid)

Answer 59

8-32 depending on species and birth takes about an hour per young

Answer 60

-The young similar to adult just pale and not fully formed - they crawl on to the mothers back where they remain for 9-14 days until first moult - after which they leave mom and go off on their own

Answer 61

-Totally unique structure - comb like structure on underside of prosoma just behind sternum and genital opening - used for sensing temperature and humidity levels and for feeling substrate - used by males (larger pectines) to follow pheremones of females

Answer 62

-They have a complete fusion of the chepalophorax and abdomen with no external divisions in body segments -Their mouthparts are on a little anterior projection called gnathosoma( made up of feeding appendages that surround the mouth)

Answer 63

-Simple head capsule has two palps or mouth feelers in front, between these there is a hypostome or sucking apparatus, which consists of tubular structures with blades on the sides and cutting blades at the tip - most species have two simple eyes om the shield above the second pair of legs, some are completely blind - these small simple eyes can only detect light intensity and movement - when tics hatch they originally only have 6 legs

Answer 64

A calcified harpoon like structure near the mouth area of certain parasitic arthropods allowing them to anchor themselves firmly in place on a host animal

Answer 65

-Ectoparasitic, feeding in blood of host -Soft bodied so they can indulge in large amounts if blood in a single feeding stage -Large bloated tics are blood filled females males don’t get that large

Answer 66

-Sperm is transferred directly by most mites and tics - others via spermatophore - larva with 6 legs hatches from egg - followed by one or more 8 legged nymph stages before adult stage is reached

Answer 67

-Adult fully engorged female tick falls from host and lays her eggs in batches in a protected area on the ground - after roughly three weeks eggs hatch and six legged larvae(pepper ticks) then climb up to the top of grass stems and await arrival of suitable host - larvae then attaches to host and engorges on meal - larvae grow and moult while in host - nymph reattaches and feeds and moults till adult - adult then feeds, finds a mate, copulates and drops off the host to lay eggs - males stay on host and dies there

Answer 68

- egg hatches into larvae which can survive for several months without feeding. - when suitable host is encountered larvae attaches themselves to ears and flanks, engorge, moult into nymphs engorge again and drop off host after 15 days -on the ground they moult again into adults after about 25 days - can survive up to a year without feeding - find second host attach below the tail and engorge in seven days - find a mate copulate fall of lays eggs and dies

Answer 69

-Female drops of host laying 3000-6000 eggs - eggs hatch within three weeks and larvae seek out a host -larvae feeds and drops of host and moults into a nymph - nymph attaches to second host, feeds, drops off and moults into adult on the ground - adult then attaches to third host and completes the life cycle (Smaller animals such as elephants shrews) (Frequents head,eyelids,mouth, cheeks, ears )

Answer 70

-Mites are a minute ectoparasite visible only under a microscope - appear all across the body of certain antelope and predators - mites cause condition known as mage - have a baglike body which is not segmented - morphologically similar to ticks where larvae hatch with 6 legs and nymphs have 8 - feed mainly on small arthropods, invertebrates eggs and other arachnids -some scavenge on decaying matter, dried skin cells, body oils and fragments of feathers. - herbivore mites have specially designed mouth parts called **stylets** adapted to suck sap from them

Answer 71

-Mouthparts on the front end have prominent cutting blades or sucking mouthparts depending on their diet - most mite species digest their food externally by regurgitating digestive fluids and absorbing the digested matter - next to the mouth parts are two pedipalps and behind these they have a pair of simple eyes

Answer 72

While adhering to skin with ambulacral suckers, the adult cuts through the skin with its chelicerae and sharp edges on the tibiae of the first pair of legs - egg laying begins within hours of the female starting to burrow. As burrowing proceeds, eggs are laid at two-three-day intervals and eggs hatch after about five days they hatch into 6legged larvae - both larvae and nymphs migrate to hair follicles in their search for food and shelter - nymphs moult into second nymphal stage which then moult into the adult stage - the development from larvae to adult takes about 6 days - as the adults wander around the skin copulation takes place and burrowing starts again to complete the life cycle - happens between ten and fourteen days

Answer 73

-Most wild animals are sub-clinical infested with mites. - mange only becomes apparent when the host is subject to stress and usually only some individuals will show clinical signs of infestation

Arthropods Flashcards

(100 cards)