Midterm Flashcards
What are the 3 body segments of an insect
- head
- thorax
- abdomen
What are 3 things all insects have
- 3 body segments
- 6 legs
- wings
What are the 5 factors that make insects successful
- flight
- small size
- reproduction
- exoskeleton
- metamorphosis
ametabolous development
no change in physical form, insect only gets larger
hemimetabolous development
body grows in instars
-incomplete transformation
holometabolous development
complete transformation
larva molts into a pupae stage
why is # of life stages fixed but development time plastic
temperature differences
- as temp increases, development time decreases
voltinism
number of generations
univoltine
one generation per season/year
multivoltine
> 1 generation per season/year
periodical voltinism
<1 generation per season/year
(cicada)
why can the number of generations per season vary for a given species
seasonal length and temperature can change between locations and years
diapause and characteristics
overwintering
-arrested development
-reduced metabolic activity
-abiotic and biotic induction cues
What are the 3 main diapause cues
- decreased photoperiod
- decreased temperature
- less resources
phytophagous
insects that feed on live or decaying plants
polyphagous
many different hosts
oligophagous
a few hosts
monophagous
one host
haustellate: siphoning
ingesting liquid food by sucking it up
haustellate: sponging
ingest food by sucking like a vacuum
ex. flies
do immature stages and adults always feed
immature always do, but adults sometimes don’t
what are 4 host location sensory cues
- visual
- olfactory
- gustatory (taste)
- environmental
What are the 4 steps of host location and selection
- habitat location
- host location
- host acceptance
- host use
insect pest definition
an insect that has a harmful effect on humans
How many of the ~1 mil insect species are pets
1-3%
what are 5 types of insect pests
- agricultural
- forestry
- structural
- disease vectors
- nuisance
injury vs. damage
injury: harm on a commodity
damage: value loss of the commodity (yield loss)
3 ways that insects can cause injury
- feeding
- altering taste (wine)
- body secretions (honeydew)
direct feeding injury
feeds on harvestable portion of plant (fruit)
indirect feeding injury
feeds on leaves roots or stems
indirect feeding damage
causes virus transmission
sign vs. symptom
sign: evidence of insect
symptom: change in plant appearance from insect feeding
density
size of pop in relation to the amount of space it occupies
what does natality (birth rate) depend on
- fecundity (# of eggs)
- fertility (# of eggs that produce offspring)
- sex ratio
density independent factors
effect does not change with density (hard freeze)
density dependent factors
effect changes with density (food of resource availability)
exponential growth of insect pop
-growth rate increaes as the pop gets larger
-r is postive
-density-independent control
-based on infinite amounts of resources
logistic growth of insect pop
- r depends on how close N is to K
-r increases and then slows as N approaches K
-s-shaped
Name some traits of K selection
-grow slowly
-pop lives close to carrying capacity
-few progeny that have high chance of surviving
Name some traits of r selection
-high birth rates
-low investment in offspring
-in unstable environments
name 5 traits of agroecosystems
- lack temporal continuity
- low species diversity
- uniform phenology
- uniform plant condition
- frequent pest outbreaks
in what ecosystems can pests reach k
forests and orchards
-more stable and diverse
dispersion
spatial arrangement of individuals within a pop
-determines pop density
What are the 4 parts of the invasion pathway
- arrival (usually by humans)
- establishment
- integration
- spread
Whats 3 differences between management of native and invasive insects
for invasive insect…
- lack of management options
- government regulation
- different scale
What are some parts of IPM
-minimal pesticides
-reduce #s
-economical and effective
-minimal impact
-informed decision making
-multiple tactics
What the main difference between IPM and organic
IPM can use synthetic pesticides and organic can’t
Describe calendar sprays of synthetic insecticides
applied on a specific day even if the insect was not present
describe economic injury level
pest presence doesn’t always mean economic damage is occurring
-level that economic injury happens
Name the 6 IPM tactics
- chemical (synthetic or natural pesticides)
- biological control
- cultural (changing the environment to make it unfavorable)
- physical (traps)
- genetic (manipulation of genes of crop or pest)
- behavioral (pheromones, repellent)
describe integration
harmonious use of multiple tactics to control single pests or groups of pests
describe management
decision-making rules based on ecological principles and economic and social considerations
prevention vs. prophylactic
prevention- prevent a pest from entering an area or stopping existing pops from becoming a pest
prophylactic- apply insecticides before a pest is present or reached damaging size
Name the 4 IPM steps
- monitor and ID
- evaluate
- manage
- re-assess
What are the 3 IPM scales
- localized (individual farms/fields)
- area-wide (requires coordination)
- precision (small scale)
What are the morphological ways to ID an insect
- taxonomic keys
- expert identification
- field guides
- citizen science and digital ID
What are the challenges of morphological ID
-immatures are hard to ID
-need to find it first
-might need special equipment
-specimen quality
-cryptic species (dif species that look identical)
COI
cytochrome c oxidase
-a mitochondrial protein-coding gene. It’s a commonly used marker for identifying species and inferring phylogenies.
why use COI
-easy to amplify
-flanking spaces in universal around species
-use universal primers
barcoding steps
- creation of a reference library for a known species
- use of that library for identifying an unknown specimen
monitoring def
systematic observation of pest pop over time
-known vs. unknown
sampling def
technique used to observe pest for the purpose of monitoring
-general vs. species specific
why monitor/ sample
- detection
- quantify pest abundance/ density
- quantify pest phenology and pop dynamics
direct vs. indirect sampling techniques
direct- samples of insect itself
indirect- samples or measurement of insect activity (plant injury)
What are the 2 needs when trapping an insect
- insect must be mobile
- trap must be able to retain what it captures
lures vs baits.
lures- pheromones or plant volatiles
baits- food-stuff or food-like stuff
wing beat monitoring
measure wing beats in trap to ID and count pests or used to lure pests
What affects trap captures
- bycatch
- temp
- rain
- crop stage
- lure age
molecular sampling
detection of pest via genetic marker
-for hard to see pests or cryptic species
-presence or absence
relative estimates
a measurement of pest population size that compares the abundance of a pest between different locations or time periods, without necessarily providing an absolute count of the total pest population
haphazard vs. random sampling
haphazard sampling- selecting a sample without any systematic method
random sampling- a rigorous process where each item in the population has an equal chance of being chosen
sequential sampling
a non-probabilistic method for collecting data that involves taking a series of samples until a researcher is confident in their results
