Midterm 1 Flashcards
Approximately how many insect species are known today?
~1.5 million
How many insect species may exist? Why might we not know all of them?
20-30 million, hard to find them all as they may be living deep in the rainforests
Where in the world are insects? Where is the only habitat that insects aren’t found?
insects have global distribution. can only not be found in the oceans
Why are insects so successful, abundant, and diverse?
because of their life history, small size, exoskeleton, metamorphosis, adaptability, wings
What about their life history makes insects successful?
high reproductive rate, short generation time. aphid may leave 10^100 descendents
What about their small size makes insects successful?
fit into diverse niches, need little food compared to other large animals, solar powered (solar energy warms them and is converted into energy)
What about their exoskeleton makes insects successful?
it is light, flexible, minimizes water loss, provides large area for internal muscle attachment, carries appendages
What about metamorphosis makes insects successful?
young and adults have different shapes and forms - allows them to specialize, larvae = feeding machines, everything designed for feeding, adults = task is for reproduction, allows to inhabit different environments - dragonflies = larvae lives in water, adults live in terrestrial environments
What about adaptability makes insects successful?
many offspring, result allows for genetic variation = rapid adaptation to environmental changes
What about wings makes insects successful?
99.9% of flying organisms are insects, dispersal and migration, mate seeking (male follows concentration gradient of females using wings), food and host location (foraging) - mosquitos flies to host using cues from host to mature eggs
What are insect roles and their relation to humans?
pollination, commercial products, biological control, insects as scavengers, insects as a food source, insects in scientific research, insects as pests
Pollination
- worth 19B in USA
- orchard fruit (apple, pear, cherry)
- many berries (strawberry, raspberry, blackberry)
- vegetables (cucumber, pepper, tomato)
Commercial products
- honey
- beeswax
- candles
- silk (silkworm)
- sex pheromone
- dyes
types of biological control
- insect vs. insect
- insect vs. plant
what is an example of insect vs. insect biological control?
cottony cushion scale: citrus pest from australia to north america.
predator = ladybird beetle. brought to north america to take care of pest
what is an example of insect vs. plants biological control?
alligator weed: aquatic plant from south america. impeding boat traffic and killing fish. predator = flea beetle. brought to control weed
insects as scavengers
feed on decomposing organic matter
- wood borers (typically beetles and fungi)
- recycle dead trees into soil
carrion feeders
- blow flies (maggots), carrion beetles, skin beetles
- vertebrates that die release - s - s - which attracts female blowflies to lay eggs
- used in forensic entomology
define maggot therapy
using maggots to eat dead skin/muscle in an infected wound in order to not have to amputate
insects as a food source
- insects for vertebrates (birds, fish, mammals, bats, reptiles, amphibians)
- insects for invertebrates
insects in scientific research
- genetics = vinegar flies (fruit flies)
- bioindicators = can use insects to gage whether an ecosystem is healthy
insects as pests
- attack cultivated plants (codling moth, mountain pine beetle)
- promote plant disease (provide entrance for pathogens, transmit pathogens)
- infest stored products (wood: termites, carpenter ants | fabric: clothes moths, dermeshed beetle | food: grain and rice weevil, flour moth
- attack humans and other animals (sting and bite: biting flies, bees, wasps) live on vertebrates (chewing lice, fleas, bed bugs)
- transmit diseases
define mechanical and biological vectors
mechanical: pick up diseases/pathogens on the outside of their body and transfers them onto other organisms through physical contact (typhoid fever, cholera)
biological: living organism that transfers pathogen inside themselves from one host to another (malaria, plasmodium)
define metazoa
many cells organized into organelles and tissues
define deuterostomes
“second mouth”, blastopore -> anus, new mouth forms
define protostomes
“first mouth”, blastopore -> mouth
define onycophora
rare, in the tropics, bilateral symmetry, segmented body, appendages, simple eyes, antennae
define arthropoda
arthro = jointed, poda = leg/foot
bilateral symmetry, segmented body - organized into regions = tagmata, specialized and jointed appendages, paired and ganglionated nerve cords, chitinous exoskeleton, open circulatory system
define chelicerata
2 tagmata - 1: cephalothorax (head/thorax), 2: abdomen
simple eyes, mouthparts: chelicera, no antenna, 8 legs = ticks, mites, spiders, scorpions, horseshoe crabs
define entognathous
having inner mouth parts, mouthparts are concealed within pouch, simple eyes, thin and pale cuticles
3 orders: 1) protura, 2) deplura, 3) collembola (springtails)
define ectognathus
having outer mouth parts
2 orders: 1) thysanura (silverfish), 2) microcoryphia (jumping bristletails)
define neoptera
new winged insects, 2 wings/1 pair, haltera needed for balance (diptera)
define paleoptera
old/ancient wings, less efficient flyers, simple and ancestral wing articulation & wing musculature
2 orders: 1) odanota 2) ephomeroptera (mayflies)
define endopterygota
wings develop internally in holometabolous insects, metabolism = change, holo = complete, wings are ony in adult stage.
Orders: lepidoptera, diptera, coleoptera, hymenoptera
define mandibulata
2-3 tagmata, compound eyes, distinct mouthparts = mandibles, maxillae, labium, antennae
define insecta
3 tagmata, 1) head with mandibulate mouthparts 2) thorax with 3 pairs of legs (wings) 3) abdomen
appeared ~400 million years ago
define myriapoda
many legs, millipedes, 2 pairs of legs per segment
scientific name = diplopoda
define apterygota
a = no/not, pteryx = wings
wingless insects
define exopterygota
wings develop externally in hemimetabolous insects = half change (nymphs resemble adults)
define orthopteroids
mandibulate mouth parts ‘chewing types’, large vanal (anal) lobe
orders: orthoptera, blatteria, dermapteria, isoptera,