Ento 210 1st EditionExam # 1 Study Guide Lectures: 1-8Lecture 1 (September 1)What are the five subphyla of arthropods?-trilobitomorpha (which are extinct)-crustacea-cheliceriformes-myriapoda-hexapoda-origin of arthropods-cambrian explosion (530 mya) which resulted in the appearance of many animalssuch as arthropods, especially around the Burgess Shale-sanctacaris is the oldest known relative of scorpions and spiders*insects first appeared around 400 mya-earliest insects were bristletails (aka silverfish)-there are about 1.5 million species of arthropods, of which about 2/3 are insects(~38% of insects are beetles)Pytophagy – eating plants  greater diversificationCrustaceans – about 52,000 species have been describedEx: barnacles, crabs, isopod (woodlice), daphnia, copepod-isopods are the only crustaceans permanently on landLecture 2 (September 3)Cheliceriformes – 2 classes -chelicerata – 2 subclasses-merostoma (water scorpions, horseshoe crabs)-arachnida (only know 3 orders)-scorpiones – venomous sting-lots of people suffer allergies from their bites-araneae (spiders) – venomous bites (almost all are venomous)-acari (ticks and mites) – can infect our skin, suck blood-pygnogonida (sea spiders)  don’t need to know these!Myriapoda (only need to know 2 classes)-diplopoda (millipedes) – live on decaying leaves-some are poisonous-2 legs per segment-chilopoda (centipedes) – have fangs, bite, very fast-one leg per segmentHexapoda-parainsecta (soil arthropods)-insecta-apterygota (wingless) – silverfish, bristletails-pterygota (winged) – some don’t use their wings anymore-paleoptera – can’t fold wings flat on body-mayflies, dragonflies, damselflies-neoptera -exopterygota (outside wings) – incomplete metamorphosis-grasshoppers-endopterygota (inside wings) – complete metaphorphosis-butterflies, junebugsWhy are arthropods important?-Arthropods help recycle nutrients, help spread plants, are sources of food, and are involved in predation, parasitism-they help humans by being a source of food, pollinate various plants, and producing useful items like silk-arthropods can also cause large amounts of damageThe Gypsy moth-eats many types of plants-has no natural predators-caterpillar hairs are very irritating to humansHuman health disease (know general info)-Malaria is the number two deadly disease (HIV/AIDS is first)-Dengue fever causes a lot of infections, not as many deaths-Sleeping sickness is 100% fatal if not treated quicklyThe Arthropod body-exoskeleton (aka cuticle) - can’t be grown in a linear fashion, must be regularly shed-provides support, protective armor-prevents water loss-arthropods have segmented bodies and appendages-they have no veins; instead the blood flows freely through the bodyWhat makes up the cuticle?-4 layers-epidermis – alive, secretes chitin-endocuticle – soft, moveable-exocuticle – sclerotization** (makes it harder)-epicuticle – very thin, waxy layer-waterproofs the exoskeleton**as the arthropod grows, water loss is a bigger issue since the surface/volume ratio decreases-more water can evaporate through the skinLecture 3 (September 8)Segmentation -tagmosis – when the segments fuse to form new units (evolutionary)-walking legs are attached to the thorax (3 legs – 3 segments)-wings are not derived from appendages of walking legs (the origin is unclear)-you can see the ancestral segmentation in some spidersex: mutation in drosophila (fly) gene that changed antennae back to legsInsect Mouthparts -labrum – upper lip-labium – lower lip-mandible – upper jaw (pair)-maxilla – lower jaw (pair)-hypopharynx –tongue like functionJointed appendages-joint is in the endocuticle-muscles attach to the inside of the cuticle wallThe nervous system-there is a major nerve cord down the bottom of the insect-the cord has many ganglia (one for each segment)The respiratory system-systems of tubes that connect outside to inside of insect-trachea -spiracles – holes in the abdomen that reach to the outside-tracheoles are smaller inside – diffuse through tissue-oxygen enters the body with passive diffusion, although sometimes the insect pumpsits body to helpGas exchange in spiders-spiders have book lungs-haemolymph transports: nutrients, hormones, immune cells, waste products-haemocyanin is an oxygen binding protein found in haemolymph-modern spiders now have an additional tracheal systemPattern of circulation-there is one artery (dorsal vessel)-each abdominal section has a “heart” – one-way valve-connected to haemolymph flow-ampullas in legs also help flowalimentary canalforegut: responsible for ingestion, transport, storage, and occasionally mechanical digestionmidgut: responsible for enzyme production (in the gastric caecum), chemical digestion (in the ventriculus), nutrient absorption-contains malpighian tubules** which act like kidneyshindgut: primarily for water absorptionSensory perception-bristles/setae – feeling, tasting-antennae, palps – smelling-for hearing:-subgenual organs - inside the legs, detect vibrations-johnston’s organ (mosquitos) – at base of antennae-tympanal organ – membrane that vibrates when air vibrates-on legs and abdomenVision-dermal detection – under the cuticle-stemmata – insect larvae-ocelli – similar to vertebrate eyes-compound eyes – individual ommatidia-only detects light if straight at it-great for detecting movementWhat’s the difference between direct and indirect flight muscles?Direct Flight muscles-most primitive-roof of thorax attached to wings, pivot point-wing goes down, roof goes up and vice versaIndirect Flight muscles-muscles that make wings go down are in middle of body  compress thorax-increase pressure in thorax so roof raisesLecture 4 (September 10)What’s the difference between poison and venom?-poison is ingested or absorbed, while venom is injectedAllergic reaction is when an allergen causes a larger than necessary reaction of the immune system-can cause drop in blood pressure  shock-irritates nerve endings (itching)*Identify the differences between types of allergic reactions: local, large local, and systemicWhat are some symptoms of anaphylaxis?-swelling, diarrhea, incontinence, difficult breathing, low blood pressure**rash or swelling are usually firstWays to manage reactions-antihistamines, steroids, epinephrine penWhat are common arthropod causes of allergic reactions?-mosquito bites, flea bits, bees, wasps, ants-inhaling arthropod parts