entm midterm 1
Terms in this set (100)
5 reasons we study insects
1. medical importance
2. economic importance
3. biodiversity (found everywhere
4. biomass (abundant)
- can be eaten
5. model system (genetics, immunity, evolution
What did Jules Hoffman win the Nobel Prize for?
discoveries concerning the activation of innate immunity, found receptor proteins that can recognize such microorganisms and activate innate immunity,
What was UCR before it was a university?
An orange farm
What insect began to devastate SoCal citrus in the early 20th century?
cottony cushnion scale
What insect was used to control this pest?
What is this technique called?
Ladybugs, beatles/ biological control
What is natural selection? and give 3 examples of each
the process whereby organisms better adapted to their environment tend to survive and produce more offspring, Galapagos finches and their beak sizes, mice coat color, tortoises and their necks
What is a phenotype?
Name different phenotypes in humans.
physical differences that can be seen in the same species, different hair, eye color, etc
What two forces interact to produce phenotypes?
genetic factors, environment, some
How is novel genetic diversity acquired?
acquired through mutation, sometimes bad, sometimes good.
What are some examples of artificial or experimental selection done by humans that support the role of natural selection in evolution?
One researcher got rid of a gene that was critical to the survival of the bacteria. Within a few generations, the bacteria was able to evolve to intake glucose once again, evolution
What are the five characteristics of arthropods
1 .Bilateral symmetry, cutting it in half would be the same for both sides.
2. Segemented body,
3. jointed Appendages,
4. tough external skeletons,
5. dorsal heart/ventral nervous system
How many pair of legs do centipedes and millipedes have
1 pair per segment for centipedes, 2 pairs per segment for millipedes
What type of eyes do insects have?
What are these eyes good at detecting?
What are these eyes composed of?
compound eyes, good at detecting movement, composed of ommetidium
What is the simple eye in insects called and what does it detect
ocelli, detects light and darkness
Name each of the body segments of an insect.
Name each of the body segments of a spider.
head (eyes, mouth, 1 pair of antenna), thorax (prothorax, mesathorax, metathroax) abdomen (spiracles, ovipositor)
spider: cephalothorax and abdomen
What percentage of organisms are insects?
more than half, plants included
What are the five reasons for insect success?
Explain why each characteristic is important
small size (insects hardly need any resources to survive), high reproductive rate (hundreds of eggs), strong external skeleton (prevents water loss, protects from predators and pathogens), able to fly, adults may not have to compete with young for resources
Why would insects desiccate or dehydrate rapidly without an exoskeleton?
water would excrete quickly, exoskeleton is impermeable, protective layer
What are the differences between growth and molting, incomplete metamorphosis, and complete metamorphosis?
growth and molting look the same, incomplete metamorphosis the young and adult will look different, still similar, maybe grow wings, different color, complete metamorpheiss look competely differnt, larva, to pupate, to adult
What are juvenile forms of insects that undergo incomplete metamorphosis called?
What are juvenile forms of insects that undergo complete metamorphosis called?
What are the different juvenile stages of complete metamorphosis called?
egg, larvae, pupa,
What are the three segments of the thorax?
Where do the legs originate?
Where do the wings originate?
(prothorax, mesathorax, metathroax), 1 pair comes from each region, mesathorax, metathroax for wings
What is the insect foot called?
What determines the structure of the insect foot?
Tarsus, Depends on the insect
Some can be sticky to used to climb surfaces (ex. Ants) while others may be long and used for jumping (ex. Grasshoppers/Fleas)
What type of mouthparts do grasshoppers have?
mandible, chewing mouth
What type of mouthparts do true bugs have?
What is the insect antenna used for
taste and smell
What are the spiracles used for?
helps with respiration
What is the ovipositor used for?
helps for laying eggs for females
Why will insects keep moving after their heads have been removed?
diffuse nervous system, ganglia that are throughout the body
What organ system runs along the upper part of the insect body?
aorta (dorsal vein)
What organ system runs along the lower part of the insect body?
What are the hairs on an insect that detect odor and taste called?
What are the three parts of the insect digestive system?
the fore gut, midgut, hindgut,
Which parts of the digestive system do pathogens ether through?
Why are pathogens able to enter through this to part of the digestive system?
midgut, they have a permeable membrane
What is the function of the malpighian tubules?
where unwanted wastes and solutes are thrown out, similar to a human kidney
What is insect blood called?
What is the normal color of insect blood?
hemolymph which is green
What is the function of the spermathecae?
where females can store male sperm.
What are the major players in the Batesian mimicry system?
What is the difference between Mullerian and Batesian mimicry?
-model: Harmful/Unpalatable organism
-mimic: Harmless/Palatable organism
there is one that is dangerous, one that is harmful. in mullerian both are harmful, batesian only 1 (model) is harmful
Why do some insects develop camouflage or crypsis that makes them hard to spot?
so they can better survive
What is unusual about the mating system of dragonflies?
can be violent
What are the purposes of the different structures in a termite mound
nest, nursery chambers, fungal gardens, tunnel-like galleries that function like air-conditioning,
How do Grasshoppers Chirp?
-Run top of one wing against bottom teeth of another wing/Stridulation
-rub legs and wings together
Why are the peppered moths in England a good example of both camouflage and natural selection?
Peppered moths before the industrial revolution were originally white and light colored, but after the industrial revolution they became dark and black colored due to the trees becoming black from the pollution.
Why are silverfish considered pests?
In what Household conditions are silverfish normally found?
Silverfish are considered pests because they eat practically anything (especially books & paper, etc.)
They like humidity or near water (ex. bathrooms, sinks, basements)
Describe the lifecycle of mayflies:
one day flies; male dies after mating; females loses wings, falls into water, lays eggs , repeat
What do grasshoppers eat?
They are herbivores; grass and other plantlife
- can eat crops
What causes grasshoppers to form swarms of locusts?
In what Geo region of the world are locust swarms most common?
Locusts form when overcrowded, and not enough resource to support its population, most common in Saharan Africa and in the middle east.
What are the difference between crickets and grasshoppers?
Crickets rub wings together; active at night
-Grasshoppers rub legs and wings together; active during the day
Where do most roach species live?
-most roach species live in the wild and are not associated with humans, The vast majority of species are found in tropical areas
What is the egg sac of roaches called?
What are the common species of roaches that are pests in the US?
-German cockroaches, American, brown-banded, Oriental
What are the different castes of termites?
What is the role of each caste?
-Queen: Produces all of the eggs needed for the colony
-King: Inseminates the queen
-Workers: Feed the queen and soldiers, Maintain the nest/colony/mound
-Soldiers: Protect the nest from invaders, Have large head and mouthparts for fighting
-Winged Reproductive: Only occur seasonally, Fly out of the nest and attempt to start new colonies
What are the purposes of the different structures in a termite mound
How do termites digest the wood that they eat?
This process, though difficult, is aided by bacteria in the gut (gut endosymbionts)
What is an ectoparasite?
Lives on surface of other organisms
What is the difference between chewing lice and sucking lice?
chewing lice- dead skin cells and hair, will bite skin and drink blood not found on humans but animals
sucking lice- pierces skin and sucks on blood from host, cannot live a long time off host
What does the term host-specific mean?
Give an example of a host-specific group of insects and a generalist group of insects.
Host specific: only wants to feed off humans or a specific animal
Example: Lice (Phthiraptera), Katydids
What are the eggs of lice called?
How can the crab louse be transmitted between people?
-through sexual intercourse or sitting in the same place (naked)
In what condition are human head lice normally found?
-usually attached to hair follicle (infestations common in elementary and middle school)
What disease do lice transmit to humans?
Why type of pathogens causes this disease?
When historically was this disease a major problem?
How was it controlled?
-Rickettsia pathogen causes typhus
-WWI-WWII major lice problem
-DDT (no longer used because harmful to many organisms), Vaccine, Antibiotics
What is the difference between antibiotics and vaccines?
Antibiotics are used to treat infection and active bacteria. Vaccines are used to provide immunity before active bacteria. It stimulates body for next infection.
What are hemelytra?
- the shortened, hardened wings of bugs. Not useful for flying
How do giant water bugs breathe underwater?
- use an air bubble and frequently go to the surface
What is unusual about offspring care in giant water bugs?
- male parental care. Carries offspring on back. Constantly runs water over eggs to keep them at optimum temperature.
- female, instead of male, is promiscuous. Actively looking for mate and mates often (usually parent w/ least investment in offspring more promiscuous)
How do water striders stand on the surface of water?
-Tiny hairs on legs that repel water and capture air
- long legs distribute weight over large distance (surface tension)
Why are there no marine insects that live underwater?
- b/c their ecological niche would already be occupied by crustaceans (anthropoids)
- water striders avoid this niche overlap by staying above water
What is the name of the economically important stinkbug?
- brown marmorated stink bug (eats crops)
What do bed bugs need to complete each nymphal stage?
How many nymphal stages do bed bugs have?
- blood meal
- 5 nymphal stages
- At adult age, it feeds as often as every couple of days while some species may survive up to a year
where do bed bugs hide during the day?
- tiny crevices and cracks: Seam of mattress. Carpet fibers, dresser, nightstand, etc. 20 ft away from individual sleeps
What disease was it recently shown that bed bugs can transmit?
How were bed bugs nearly eradicated ~50 years ago?
What are some reasons for the recent resurgence in bed bugs and how can it be controlled?
-DDT was used to eradicate them.
-resistance to insecticides
-increased international travel
-more secondhand furniture?
-crossed economic line?
Trained dogs to sniff them out
Insecticides they aren't resistant to
Extreme heat or cold
What unusual form of crypsis do assassin bugs employ?
What is the purpose of this crypsis?
-Cryptic by putting a the carcasses of prey on its back so that it ends up smelling like the prey and allowing it to get closer its prey or lure its prey towards them without alerting it
How do kissing bugs transmit the parasite that causes Chagas disease?
-It poops on your head, then when you itch, you move the poop into the wound
-They are born uninfected, but if they get meal from someone w/ disease, then they can spread it. sucks to suck (pun intended)
In what geographic region is Chagas disease most prevalent?
What are symptoms of Chagas disease?
Where do kissing bugs normally bite?
-Found in Central and South America.
-Includes fever like symptoms, redness, swelling. The chronic stage includes a damaged digestive system, damaged heart, and often leads to premature death.
-Bites usually occur near the mouth/eyes (hence the name kissing bug).
Wby is Chagas not a major problem in southern California despite the presence of both the parasite and the vector?
-no badly built buildings like the ones in South America
In what three different ways do aphids cause damage to plants?
-Removes nutrients (direct), transmits viruses (cosmetic damage), fungus grows on the plant from the honeydew they secrete (indirect)
What does "cosmetic damage" mean when referring to fruits and vegetables?
-It means it's visually unappealing
what is unusual about the aphid life cycle?
Why are parasites generally considered to be better biological control agents than predators?
Predators often won't work because they may migrate to new areas since they don't target single pests (ex. Lady Beetles eat aphids but also other insects).
In the aphid-ant mutualism what benefit do the ants receive?
What benefit do the aphids receive?
-Ants eat the honeydew that the aphids secrete and the aphids in return receive protection from predators by the ants
How do aphids alert each other about the presence of parasites/predators?
-cornicles: alerts others to escape (odor)
What tree does the California the lerp gum psyllid attack?
Why did biological control work better on coastal populations of the lerp gum psyllid than inland populations in California?
-the parasitoids were collected from the coast in Australia and were better adapted to the coastal climate
What disease does the Asian Citrus Psyllid transmit to citrus?
What type of pathogen causes the disease?
-citrus greening disease
-The type of pathogen is bacterial
Where and when did the Asian Citrus psyllid first invade the United States?
-1998 in Florida
Why is biological control unlikely to eradicate the Asian Citrus Psyllid threat in California?
-biological control only delays the population, not prevent
What are the symptoms of citrus greening disease on trees?
-asymmetrical leaf discoloration
What are the two most common types of transgenic crops in the US?
-Most common transgenic crops include corn, cotton, rice, soybean, canola, sugar beet
Where do cicada larvae live?
Where do cicadas females oviposit?
-bark of the tree
How do cicadas make their characteristic noise?
-Male: Tymbal - done by shaking abdomen
-Female: Stridulation (like crickets)
What is the difference between different broods of cicadas?
-The difference is in the years they come out of their eggs.
-13 or 17 years
Describe the scale life cycle
Males fly, females get stuck onto tree (immobile), males lay egg onto female.
What product is made from cochineal scales?
How is it made?
Why is this product becoming less commonly used?
-Red dye can be made from cochineal scales
-Grow cacti, cut off scales, boil
-Product being less commonly used b/c people think it's cruel and weird to use real ---insects in dye/coloring.
-low cost in artificial dye
What important disease does the glassy-winged sharpshooter transmit?
What type of pathogen causes this disease?
Pierce's Disease caused by bacterium Xylella fastidiosa
Why hasn't the glassy winged sharpshooter invaded Northern California?
-not used to the climate
How do ant lion larvae catch their prey?
-Eat ants/other small insects
-They dig a hole/pit and burrow themselves down in the center. Then they wait for an ant to fall inside and they catch their prey.
-If they don't catch their prey right away, they use other tactics, like throwing dirt up at the inset so it doesn't escape.
What are the 5 characteristics of anthropods?
-Dorsal heart/ventral nervous system