Entomology Exam 2

primary aquatic orders

all members

immatures of ephemeroptera, odonata, plecoptera, trichoptera, megaloptera

secondary aquatic orders

some members

semi aquatic or specialized: neuropteran, orthopteran, hymenoptera

methods of getting O2 under water

breathe air with a tube

bring a bubble of air with you

diffusion

gills

respiratory pigments

breathe air with a tube

many insects have modified appendages that allow them to breathe air

eg: Nepidae

bring an air bubble with you

physical gill, as the oxygen gets depleted in the bubble, O2 from the water diffuses in and when its too depleted go to surface with a new bubble

diving beetles that hold a bubble of air under their elytra over their spiracles

dysticidae,hydrophilidae,halipidae

diving bugs that hold a bubble with airs on their ventral side

notonecidae, corixidae

fast flowing cold water means oxygenated water is constantly replenished around organisms

diffusion

gills work by

increasing surface area for diffusion

respiratory pigments allow

insects to store oxygen

eg hemoglobin

lotic habitat characteristics

flowing water

high O2 content

high habitat heterogeneity

external inputs such as leaf litter and wood

banks have tree-vegetated riparian zone

riffles

shallower,stony, fast-flowing sectionsp

pools

deeper areas

erosion

sediments taken from solid and carried away in water

those that live in strong currents are dorsoventrally flattened

often with laterally projecting legs

silk production

often live in benthos of streams between peebles and rocks

characteristic fauna of lotic habitats

lentic habitat characteristics

standing water

sizes vary from vernal pools to ponds and lakes

low O2 content

low habitat heterogeneity

limnetic zone

penetrated by ligth

littoral zone

near the shore where vegetation can grow

profundal zone

little to no light

insects adapted to water surface habitats

most within littoral zone

hydrofuge hairs

tarsal claws

detergent propulsion

divided eyes

insects adapted to pelagic zone

most in limentic zone

phantom midges, water boatman

insects adapted to profundal zones

chironomidae: non-biting midges

shredders

break up leaf litter and dead wood

collectors

filter-feeders on suspended particles

scrapers

graze algae off of solid surfaces

predators

feed on all other feeder types

river continuum concept

describes how stream ecosystems vary from headwaters to downstream and lastly to large ricers

upstream characteristics

highly shaded

narrow bed

low primary productivity

ecosystem respiration high

downstream characteristics

high light

wide bed

high primary productivity

lower ecosystem respiration

headwater characteristics

steep slopes

limited photosynthesis

leaf litter inputs

macro-invert diversity

springe, seeps-cold temps

transfer zone characteristics

some shading

channel widens and deepens

algae, submerged vegetation

water velocity increases

temperature, turbidity, and sediments increase

depositional zone characteristics

energy supplied by upstream DOM

diverse flood plain

omnivore fish species

drifting zooplankton and phyotplankton

integument

the outer covering of the living tissues of an insect

function of integument

water loss prevention

protection

support

regulates O2 flux

muscle attachment and movement

3 layers of integument

basement membrane

epidermis

cutile

epidermis

single cell layer of secretory tissue that produces the cuticle and part of basement membrane

regulates molting, type of cuticle secreted and placement of specialized cells

epidermis

inner sheet of connective tissue that separates the hemocoel from the integument and supports epidermal cells

basement membrane

cuticle

chemically complex layer that varies among and within insects

and consists of chains of chitin embedded in a protein matrix

tough,outer,acellular, secreted by cells of epidermis that is insoluble in water, dulites acids dilutes alkalis, alcohol, and all organic solvents

cuticle

3 layers of cuticle

endocuticle

exocutile

epicutile

procuticle

soft, chitin-rich cuticle, newly secreted by epidermis

exocuticle+endocuticle

exocuticle

scerletized cuticle

sceritization

process of hardening and darkening in exoskeleton via modification of the structure of both the proteins and chitin fibers

scleritization requires

amino acids tyrosine or phenylalanine

endocuticle

consists of unscelortized inner part of the procuticle that remains flexible

epicuticle

created by secretions from multiple sources deposited outside procuticle

what do dermal glands do to protect the wax layer of the epicuticle

secrete a cement atop the epicuticle

mix of hydrocarbons,alcohols, and fatty acids

wax

function of wax

prevent water loss

helps walk on water

pathogen resistance

insecticide resistance

camouflage

deter predation

communication

function of color production

protection from predation, solar/uv radiation

color production communication works by

attracting mates

thermoregulation

intra and inter individual recognition

2 mechanisms of color production

physical (structural colors)

pigmentary colorsp

pigmentary colors

results from absorption of visible light by chemical compounds

physical (structural colors)

result from light scattering, interferences, and diffraction

derived from protuberances on cuticle

physical colors

spines

mutlicellular, undifferentiated epidermal cells

setae

hairs- multicellular specialized cells

sensory of tactile environment

often modified into scales

acanthae

unicellular sclerotized protuberances that are hollow inside and some have pores under terminal plate for secretion

microtrichia

subcellular with several extension per cell, hairlike: solid cored of exocuticle covered by thin layer of epicuticle

4 main types of structural colors

spines

setae

acanthae

microtrichia

not metallic or iridescent, but vary enormously and are often derived from excretory products not involved in biochemical pathways

pigment colors

3 main tagmata of insects

head, abdomen, thorax

head

sensory perception , neural integration, and food gatheringth

thorax

for locomotion and machinery

abdomen

houses the visceral organs including components of the digestive, excretory and reproductive systems

insect tagmata evolution

segmented worms→arthropods→ insects

function of head

holds feeding appendages

hold important sense organs

contains and protects the brain

whats on the head

mandibles

specialized mouthparts

antennae

compound eyes

sometimes ocelli and other specialized features

prognathous

mouthparts directed forward and project anterior toward eyes

hypognathous

mouthparts directed downward relative to body, immediately ventral to head capsule

opisognathous

sucking beak is directed toward rear, beneath thorax

mandibulate

feeding appendages that are mostly complete, freely movable and not united into beak

parts of mouthparts

labrum

mandibles

maxillae

labium

labrum

upper lip

contains chemosensory sensilla

mandible

heavily sclerotized jaws that represent limbs that lost their distal segments

inner edge modified for biting

maxillae

2nd pair of jaws that are less massive and retain segmentation of appendages: sensory function

labium

lower lips

sensory function: palps of maxilla and labium function to taste and feel food

human importance of mouthparts

disease transmission and effectiveness of pesticides

4 main types of mouthparts

mandibulate, piercing-sucking, nonpiercing-sucking, mouthhooks

functions of mandibulate

hold,catch, manipulate and bite food

defense

courtship

construction of nests and shelters

mandibulate predators have

sharp apical teeth

mandibulate herbivores have

obtusely angled cutting teeth and basal grinding molars

piercing sucking mouthparts

feeding appendages where one or more are modified into a tubular organ for consuming liquid food

functions of piercing sucking mouthparts

pierce integument and suck fluids

nonpiercing-sucking mouthparts

feeding appendages where one or more modified into a tubular organ for consuming liquid food

functions on nonpiercing sucking mouthparts

to intake water and dissolved nutrients

suck fluids (nectar,honeydew, sweat)

mouthooks

larvae of diptera have highly reduced and invaginated head into thorax

move vertically

larvae with mouthooks feed on

variety of soft, semi liquid foods, including decaying matter and living plant and animal tissue

advantages of compound eyes

field of view:many insects can see in every direction

dual vision: see both dark, light, and color

disadvantages of compound eyes

resolution is lower

ommatidia

sensory cartridges in compound eyes

ocelli

simple eyes that are very sensitive to small changes in light

detect movement

stemmata

eyes in larval insects

type of simple eye

high light sensitivity, fast speed, and low resolution

3 type of antennae

scape

pedicel

flagellum

function of antennae

sensory

communication

movement detection

johnstons organs

mass of sensory cells that detects movement in antennae located within pedicel

3 segments of thorax

prothorax, mesothorax, metathorax

spiracles

openings for gas exchange

present laterally on mesa and meta thorax

6 main segments of legs

coxa

trochanter

femur

tibia

tarsus

pretarsus