ESPM 42 Midterm 1
biodiversity
- the variety of life on Earth (genes to ecosystems, microbes to humans) - valued for natural ecosystem services that living organisms provide - threatened by habitat loss, invasive species, pollution, climate change - insects significant contribution
phylogenetic trees represent
- time - ancestry - relationships - character evolution - taxonomic groups - are predictive
epicuticle
- top layer of exoskeleton cuticle - wax/cement layer - protects against moisture loss
hemiptera
- true bugs i.e. bed bugs, aphids, cicadas, stink bugs - one of the big 5 orders with around 80,000 species - many are plant feeding but some are predators and some feed on blood - aphid poo called honeydew is eaten by some ants that tend to them - piercing, sucking mouthparts
phylogenetic tree node
- two branches connect at a point - represent common ancestor of two lineages
upside-down
- ventral main nerve cord - cord runs along belly instead of back like humans
natural history
- whole organisms, their relationships and interactions - pattern and observation - the story of the natural world, scientific, question driven, descriptive, historical
success: trophic linkages
- with plants - predator/prey - parasitoid/host - decomposers - pollinators
homo sapiens holotype
there is none
Tewksberry reading
understanding the natural history of organisms is essential to human health, food security, conservation, and management
success: flight
- 300 mya - food specialization - escape from predators - mate acquisition - dispersal and migration
exoskeleton cons
- growth must occur in discrete stages - size limiting factors and the surface area to volume problem - mass increases faster than muscle strength - overstress of exoskeleton would lead to buckling - pin joints under excessive stress - limits to respiration rate
alimentary canal
- gut, tubular structure - foregut - midgut - hindgut
insect superclass
- hexapoda - insects and near relatives
abdomen
- houses organs for digestion, reproduction, excretion - 9 to 11 segments - no true walking appendages
bilateria
- humans and insects part of this group - organisms that are bilaterally symmetrical - true for most insects - symmetry not perfect - last common ancestor 500 may (lots of evolution)
Anna Botsford Comstock
- husband professor at Cornell whose students went on to be entomologists - illustrated many books on insects including engravings for more than 600 plates in Manual for the Study of Insects
tarigrada
- in ecdysozoa but not insects - minute, near relatives of arthropods - survived being taken to outer space and back to Earth - able to take metabolism almost down to zero
insects they are... (part 2)
- inside-out, upside-down and full of fluid and tubes - fluid filled because open circulatory system for hemolymph - full of tubes because tracheal system of respiration
Marcello Malphighi
- internal anatomy of silkworm - early entomology - challenged spontaneous generation - good illustrations
foregut function
- invagination of the outside of the insect for ingestion - lined with water-proof cuticle - transports and crushes food - some digestive enzymes or feeding aids may be added ins alive (i.e. anesthetics for blood feeders) - may store or crush food
jointed exoskeleton
- key feature of arthropods (inside-out) - multi-layered shell (no gaps) - varies dynamically through development and in different regions of the body - armor analogy no good because has gaps
binomial names
- linnaeus - genus + specific epithet - sometimes author name at end
midgut
- main digestive and absorptive portion of gut - not made of cuticle - delicate membrane that secretes enzymes and absorbs nutrients
malphigian tubules
- maintain ion (salts) balance of hemolymph - eliminate breakdown products (waste), most toxic of which are nitrogen - empties into beginning of hindgut
hindgut parts
- malphigian tubules - rectum - anus
mantodea
- mantids - highly predatory and use modified raptorial front legs - some are extremely well-camouflaged - females exhibit sexual cannibalism only about 15% of the time - big eyes - raptorial front legs
nomenclature
- system of scientific names for taxa - rules/conventions for formation, treatment, use of those names - internationally agreed, quasi-legal procedure
insect major body regions
- tagmata - result of tagmosis or grouping of segments into a functional unit - series of segments fused together
taste/smell
- surface, air, and liquid chemical detection - multicellular insect chemical sense organs
function/attributes of types
- acts as an objective basis for the linking of nomenclature to taxonomy - voucher/supervoucher of research - single datum that provides a fixed reference point for our character descriptions - not necessarily average or typical in the sense of being common form - can't represent variation
arthropodoa
- arthropods - insects, spiders, crabs, etc.
phylogenetic tree root
- at bottom of diagram - common ancestor of all descendants - from here to terminal represents past to future/present
phylogenetic tree terminal
- at end of tree paths - can be taxa, individuals, species
hymenoptera
- bees, ants, wasps - last of the big 5 with 150,000 species described and many more to be described - most important pollinators for human crops - include the only group of insects with a true sting - two pairs of wings (or none) - biting, chewing mouthparts - incredible array of forms, many modified for parasitic life
coleoptera
- beetles - biggest of the big 5 with > 350,000 species - includes the most massive and nearly the tiniest of insects - ex: tiny beetles that live in the pores of fungus - forewings modified into hard covers called elytra
Phylum Arthropoda characteristics (6)
- bilaterally symmetrical - segmented (jointed look) - exoskeleton (shed skin to grow) - open circulatory system - ventral nerve cord - dorsal artery
complete metamorphosis
- body form is specifically adapted for growth and development versus reproduction and resource location
endocuticle
- bottom layer of exoskeleton cuticle (closest to epidermis) - microfibers of chitin surrounded by matrix of protein
phylogenetic tree sisters
- branches that break off from a node - share a common ancestor
insect thorax
- center of locomotion - legs/wings - 3 segments: pro, meso, and metathorax - meso and meta bear wings
nervous system
- cns organized in series of segmental ganglia - ganglia interconnect nerves to sensory organs/muscles - insect brain consists of several groups of large ganglia in the head - primitively one ganglia per pair segment, now more fused
blattodea
- cockroaches and termites - most cockroaches are not pests - termites are more social than humans - in USA termites cost 5 billion/yr to remove - 2 pairs of wings, folded roof-like over the body or no wings - large, shield-like prothorax - white ant-like workers and flying reproductive forms
insect eyes most sensitive to
- contrast within an ommatidium and between ommatidia - movement across ommatidia
subjective synonym
- different published names for the same species
insect brain
- distinct clump of ganglia - associated group of ganglia is subesophageal ganglion under alimentary canal - less neurons than humans (100,000 - 1,000,000) - small percentage of body size
heart
- dorsal artery or "heart" - open circulatory system - heart is at the top, above the gut
odonata
- dragonflies and damselflies - aquatic juveniles - predacious - males have two kinds of genitalia in different places on their bodies - very large eyes - 2 pairs of wings held horizontal or straight above body (more spread out than mayfly)
exoskeleton pros
- efficient at small size - tubular design is stronger than rod at less weight - flexible and light enough for flight - provides good protection for soft internal structures
Darwin
- evolution - start looking at patterns - interpretation of observed and description of patterns - origin of the species
evolution reading
- evolution doesn't work the way you think it does - evolution is not a straight line, even though drawn that way
layers of exoskeleton (top to bottom)
- exoskeleton = integument - outside - non-living cuticle - living cells, epidermis (secrete cuticle)
Bates
- famous european entomologist/biologist/explorer - same time as Darwin and Wallace
Carolus Linnaeus
- father of taxonomy - included insects in the things he named, validating them for study - systema naturae
Woodworth
- first trained entomologist to assume teaching duties in California - entomology recognized as separate field at Cal because of him
diptera
- flies - a big 5 order with about 150,000 species - incredibly diverse and interesting life histories - most medically important order for humans - complete metamorphosis - only one pair of flight wings
circulation system
- fluid filled - open-body cavity with hemocoel, organs, and hemolymph - no true blood vessels except for muscular dorsal vessel
trilobites
- fossil taxa in arthropod tree - fossils only
respiratory system
- full of tubes - tracheal system is full of air tubes - key to insect success on land - extracts oxygen from the air
name part rules
- genus uppercase, italics - epithet lower case, italics - first time writing add author name and year where appropriate - name + year in parentheses if originally described in different genus (ICZN) - always use genus + epithet - set off from text - names in taxonomic latin - after first use when clear can abbreviate genus w one capital letter, don't start sentence w abbreviation
aquatic insect respiration
- gills or direct diffusion - feathery gills on tails to wave around and capture gas
ecdysozoa
- group that includes insects and relatives - things that growing by shedding exoskeleton/thick skins
hexapoda
- superclass of insects and relatives - 1 pair of antennae - 3 major body regions (head, thorax, abdomen) - 3 pairs of walking legs - most have wings (insecta)
ephemeroptera
- mayflies - aquatic juveniles - very important to freshwater ecology and act as indicator species - only living insect order with a sub-adult molt - 2 pairs of wings held straight above the body - 2 or 3 long threadlike tail filaments - reduced mouthparts (don't eat much as adults mate, then die)
touch
- mechanoreceptors - every receptor of multicellular origin - seta or hair connects to sensory organ
success of insects (5)
- metamorphosis - flight - sensory and neuro-motor sophistication - small size and large numbers - trophic linkages, generation times and specialization
exocuticle
- middle layer of exoskeleton cuticle - relatively rigid - microfibers of chitin surrounded by a matrix of protein - sclerotization: individual protein molecules are linked together by some quinone compounds
foregut parts
- mouth - oesophagus - crop - proventriculus
holotype
- name bearing type specimen - all validly named species have a single individual selected to act as name-bearing type - usually picked by original describer
type
- name-bearing specimen associated by description and publication given the rules of nomenclature
onychophora
- near relatives of arthropods - have slime glands that shoot glue used for prey capture/defense - ecdysozoa but not insects
what is regulated by taxonomy codes?
- nomenclature stability and clarity - universality - uniqueness
function of hemocoel
- not gas exchange - transport nutrients, hormones, heat, defensive cells, etc.
lepidoptera
- one of the big 5 with nearly 300,000 species - most are night-flying moths, only about 17,000 are butterflies - the caterpillar is the most important stage for economic impact - 2 pairs of wings, folded roof-like over the body or straight above the body - wings and most of the body covered in scales (modified hairs) - moths have feather antennae, butterflies have long skinny ones
insects and hemoglobin
- only found in 3 types of insects so far - bloodworm (chironomid fly) - backswimmer - bot fly
mushroom body
- part of insect brain associated with learning - if large, elaborate associated with social and learning behavior in insects - ex: bees can learn scent and remember it
tracheae
- part of tracheal system - branched, cuticle-lined and water-tight
spiracles
- part of tracheal system - like spiral, open/close to admit air exchange and admit moisture
tracheole
- part of tracheal system - where oxygen and carbon dioxide exchange in tissues occurs - cells all nearby - gas movement is by simple diffusion and some pumping
properties of exoskeleton
- physical protection - environmental control and selective permeability - mobility and movement - nearly everything you see - naturally produced biocomposite
how are names regulated?
- priority: first published name is the correct one to use - availability: properly published name is available - validity: correct name to use - no case law
challenges mediated by exoskeleton
- protection - nutrients - breathing mating
purpose of taxonomy of species
- provide unique name for every species and higher category covered by governing rules - rules cover how to name, not what to name
Wallace
- records some of the first cases of mimickry - famous european entomologist/biologist/explorer
phylogenetic tree branch
- representative of lineages of interbreeding organisms over time - lineages come to terminals
insect head
- sensory - ingestion - brain - mouth parts for chewing: maxillae, labrum, labium - mouth parts can be modified (some for biting, some for sucking or piercing)
success: sensory
- sensory systems highly organized - allows insects to sense and interpret environment on fine scale - specialized cells respond to mechanical, thermal, chemical, and visual cues - olfaction acute
success: speciation and generation times
- short generation times facilitate adaptation to new environments and speciation - correlation between size and generation time - allows for resource specialization
success: small size
- small size means large numbers - richness (many species, 9-% of terrestrial animals) - dominance (large biomass) - abundance
chelicerata
- spiders, mites, ticks, scorpions - subphylum of arthropoda - no antennae - six pairs of appendages - first pair are chelicerae - no distinct head
tracheal system parts
- spiracles - tracheae - tracheole
vision
- stemmata - larval eyes - ocelli - adult simple eyes - compound eyes are composed of many light sensing units called ommatidia - insects see mosaic and typically into UV (rarely IR) range
hindgut function
- storage and passage of digested food and excrement - some absorption, especially water - cuticular like foregut
taenidia
- stripes, spiral thing - rings that allow insects to move and bend without the respiratory system getting pinched off - slightly sclerotized
myriapoda
- subphylum of arthoropoda - millipedes, centipedes - antennae - many pairs of appendages on many body segments - distinct head - centipedes mean
crustacea
- subphylum of arthropoda - crabs, lobsters, shrimp, isopods, water fleas, barnacles - 2 pair of antennae - many pairs of appendages on many body segments
hearing
- substrate vibration - nearby air/water vibration - distant sound - sound sensitive organs found on many parts of the body in different insects instead of ears - acoustic trachea
inside-out
have exoskeleton
insect class
insecta
arthropods they're...
inside-out and upside-down