BIOL 3454 1st Edition Lecture 25 Lecture 11 14 I II III IV V VI VII VIII IX X XI XII XIII XIV XV XVI XVII XVIII XIX XX XXI XXII XXIII XXIV XXV XXVI XXVII XXVIII XXIX XXX XXXI XXXII XXXIII Circulation Tubular heart creates peristaltic waves that moves hemolymph through the only circulatory vessel the dorsal aorta Gas exchange Goal in a terrestrial animal an efficient respiratory system that maximizes O2 and CO2 exchange while minimizing water loss Insects use a tracheal system opening s are small holes called spiracles Tracheae are composed of a single layer of cells lined with a cuticle that is shed during molts Expansion and compression occur with movements of jaws and or limbs In aquatic species tracheae have similar function but more gas exchange occurs across cuticle Excretion and water balance Insects and spiders independently evolved Malpighians tubules Waste product usually uric acid Leaf feeding insects ingest and excrete large amounts of fluid Aphids form honeydew sometimes ranched by ants Nervous system and sensory organs NS resembles that of a large crustacean lots of ganglia fusion Have excellent sensory perception Mechanoreception detected by seta and sensilla distributed across the body Auditory very sensitive sensilla with tiny hairs of tympanal structures some on legs to detect vibrations some moths can hear the ultrasonic sonar of bats to avoid it Chemoreceptors bundles of sensory cells in pits how masquitos can sense increases in CO2 Other senses some can sense temp humidity gravity and have proprioception muscle stretch and body position Insect vision 2 types Simple most larvae many adults usually measure light intensity and direction no images Compound thousands of ommatidia can often see much more than we can although probably is less resolved more fuzzy the eye itself can usually process more info than we can for flight Many can see UV Reproduction Parthenogenesis common but sexual reproduction the norm Separate sexes Fertilization usually internal Spermatophores ancestral some groups still use them Many insects stroe sperm and mate only once in their lifetime rouches Most lay many eggs Growth and metamorphosis These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute XXXIV XXXV XXXVI XXXVII XXXVIII XXXIX XL XLI XLII XLIII XLIV XLV XLVI XLVII XLVIII XLIX L LI LII LIII LIV LV LVI LVII LVIII LIX LX LXI LXII LXIII LXIV Ametabolous no life stages babies are miniature adults mature gradually Hemimetabolous gradual or incomplete metamorphosis Holometabolous almost 90 of all insects have a true larval stage then pupa adult emerges Larvae and adults are very different Defense Exhibit both cryptic camouglage amd aposematic warming colors depending on species life stage food supply etc Often exhibit mimicry Exoskeleton very protective Some have chemical poisons or venoms Some aggressive communication chemical visual auditory and tactile signals pheromones secreted by one individual and influence the behavior or physiology of another sound often used to attract mates lots of tactile and visual communication Eusociality One colony working towards the common goal of survival and reproduction Exhibit polymorphism or caste differentiation Honeybees may have thousands of individuals in a single colony 1 queen several hundred drones and many workers haplodiploidy Works on the principal of shared relatedness Beneficial insects Bees pollinate 14 billion dollars worth of food crops every year in the US Many species are predatory on other insects pests Scavengers and decomposers help clean the world Harmful insects Cause trillion of dollars in economic impact on a global scale every yr Agricultural pests every agricultural crop Disease mosquitos malaria yellow fever west nile lymphatic filariasis and many more fleas plague flies typhoid sleeping sickness Native plant distraction deforestration gypsy moth hemlock woody adelgid spruces budworms various beetles Property damage bedbugs cockroaches and moths