Nervous system (blue) Insect Internal Systems and Physiology. Decentralized nervous system. Synapse gap 8/22/2012

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Dayna Bates
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1 Nervous system (blue) Insect Internal Systems and Physiology Decentralized nervous system Brain (left) several lobes Ventral nerve cord Ganglia in many segments masses of nerve cells Synapse gap Synapse gap 1

omnivores Herbivores, predators, scavengers, omnivores 3 sections separated by valves Throat, esophagus, crop Limited

2 Ion channels along nerve cell Neurotransmitter receptor sites Blocking receptor sites Affecting channels that allow balance Block enzymes that break down transmitters Synthesize and modify molecules Herbivores, predators, scavengers, omnivores Herbivores, predators, scavengers, omnivores 3 sections separated by valves Throat, esophagus, crop Limited digestion Lining shed at molt No major sections, protective layer Major enzyme activity, most digestion and absorption Crop Foregut Midgut 2

Undigested waste eliminated Water resorbed Lining lost at molt Hindgut Excretory System Malpighian tubules

amounts of liquids continuous flow 50% 60% ingested N is used Need rapid elimination of excess water to

removal of water thru rectum Midgut Digestive tract Sap Feeder Foregut Filter chamber Hindgut Rectum

3 Undigested waste eliminated Water resorbed Lining lost at molt Hindgut Excretory System Malpighian tubules & rectum Wastes in blood enter tubules Most water resorbed Dry feces excreted Sap feeders Ingest large amounts of liquids continuous flow 50% 60% ingested N is used Need rapid elimination of excess water to avoid dilution of hemolymph and better enzyme activity Filter chamber water from mid to hind gut Rapid removal of water thru rectum Midgut Digestive tract Sap Feeder Foregut Filter chamber Hindgut Rectum Malphigian tubules the kidneys Wastes and water are absorbed into the green fingers and eliminated Circulatory system (yellow) 3

proteins, hydrostatic pressure Little role in respiration Some cutaneous diffusion in small stages Oxygen

4 Circulation Open circulatory system Tubular dorsal aorta helps with circulation Insect blood cells Destroy or encapsulate foreign particles, wound healing, nutrient & hormone movement, storage of sugar and proteins, hydrostatic pressure Little role in respiration Some cutaneous diffusion in small stages Oxygen directly to use sites via tubes valve like opening can open and close to regulate water loss gas transport ventilation 4

Reproduction Female Male Ovary set #of eggs for species Spermatheca for sperm storage Fertilization occurs when

At end of abdomen Testes for sperm production Seminal vesicles for sperm storage Accessory glands Spermatophores

genetically diverse individuals, allows change 1. Fast, easy, reliable fewer steps less to go wrong (+) 2.

5 Reproduction Female Male Ovary set #of eggs for species Spermatheca for sperm storage Fertilization occurs when eggs are laid Ovipositor egg layer Accessory gland for glues, egg case material, etc. At end of abdomen Testes for sperm production Seminal vesicles for sperm storage Accessory glands Spermatophores (sperm packets) Parthenogenesis development from unfertilized egg Advantages to Sexual Reproduction Produces genetically diverse individuals, allows change 1. Fast, easy, reliable fewer steps less to go wrong (+) 2. Less energy use finding mate, etc. (+) 3. Rapid response to change (+) 4. Low genetic diversity ( ) Reduces harmful mutations May be a combination of both 5

mones chemical messengers Hormone works internally to

enabling it to communicate with other members of its own

response in a individual of another species.

6 mones chemical messengers Hormone works internally to regulate activities of tissues or organs. They affect many different processes. Pheromone released by an organism into its environment enabling it to communicate with other members of its own species Kairomone released by an organism that induces a response in a individual of another species. Aggregation Japanese beetles, blister beetles Alarm honey bee sting, ants Marking prevent egg laying Sex released by female to attract male. Used for survey and mating disruption Entfacts 200, 203, 212, 221 Trail trail marker for ants, ETC 6

7 Aggregation Japanese beetles, blister beetles Alarm honey bee sting, ants Marking prevent egg laying Sex released by female to attract male. Used for survey and mating disruption Entfacts 200, 203, 212, 221 Trail trail marker for ants, ETC A cockroach may live 9 days without a head and will respond to stimuli Dehydration and / or starvation eventually do it in 7

Internal Morphology. 1.Cut the legs and wings (if present) off your specimen. 5.Use forceps to pull skeleton apart, exposing internal systems.

Internal Morphology. 1.Cut the legs and wings (if present) off your specimen. 5.Use forceps to pull skeleton apart, exposing internal systems. Internal Morphology Insect Dissections Often the best approach to understanding internal morphology is by way of a dissection. For this reason, the entire chapter should be treated as a laboratory activity.