Arthropod Classification, Morphology, and Life History

Prevent Disease, Disability and Premature Death Objective هدف Recall general characteristics and the biology of arthropod vectors/pests for identification fundamentals.

Prevent Disease, Disability and Premature Death Overview مرور Arthropod Anatomy Arthropod Life Cycles Impact of Arthropods & Pests

Prevent Disease, Disability and Premature Death Hierarchal Classification KingdomPhylum (PhylaClassOrderFamilyGenus (Genera)Species

Prevent Disease, Disability and Premature Death Hierarchical Classification of Arthropods Kingdom -- Animalia (animals) Phylum -- Arthropoda (the arthropods: flies, spiders, etc.) Class -- Insecta (insects), Arachnida (spiders), & many others Order -- Large grouping of broadly related arthropods within each class class Family -- Smaller grouping of related arthropods within each order Genus -- Closely related organisms within each family Species -- Specific name of an organism

Prevent Disease, Disability and Premature Death

Hierarchical Classification of Selected Species KingdomAnimalia PhylumChordata Arthropoda ClassMammalia ArachnidaInsecta OrderPrimatesCarnivoraAraneaeDiptera FamilyHominidaeCanidaeTheraphosidaeCulicidae GenusHomoCanisBrachypelmaAedes SpeciesHomo sapiens Canis lupus Brachypelma smithi Aedes aegypti Common Name HumanWolfMexican Trantula Yellow Fever Mosquito “Keeping Precious Creatures Organized For Grumpy Scientists”

There are many arthropods.

Prevent Disease, Disability and Premature Death Characteristics of an Arthropod Hard exoskeleton (external skeleton) Paired, jointed appendages (legs, antennae, etc.) Ventral nervous system (runs along the bottom) Dorsal circulatory system (runs along the top) Tubular digestive system

Characteristics of an Arthropod Hard exoskeleton Ventral nervous system Paired, jointed appendages Tubular digestive system Dorsal circulatory system

Prevent Disease, Disability and Premature Death Characteristics of an Arthropod Specialized Mouthparts: Different arthropods utilize different sources of food; therefore, their mouths have evolved to accommodate the consumption of these specific foods Chewing: modified like jaws for chewing food Piercing-sucking: modified for penetrating surfaces and sucking up blood or other fluids Sponging: modified for sponging up liquids

Prevent Disease, Disability and Premature Death Selected Classes of Arthropods Class Insecta -- insects Class Arachnida -- spiders, scorpions, ticks, mites Class Chilopoda -- centipedes Class Diplopoda -- millipedes

Prevent Disease, Disability and Premature Death Characteristics of an Insect ( Phylum: Arthropoda; Class: Insecta) Three body regions (segments): head, thorax, abdomen Three pairs of legs on the thorax Most have two pairs of wings as adults, some have one pair, some have none One pair of antennae on the head Compound eyes

Thorax Abdomen Mouthparts 3 Pairs of legs Head Antennae Wings Characteristics of an Insect ( Phylum: Arthropoda; Class: Insecta) Compound Eyes

Prevent Disease, Disability and Premature Death Two body regions (cephalothorax and abdomen) Simple Eyes Four pairs of legs as adults Larval ticks & mites have three pairs then four pairs as nymphs and adults No wings Characteristics of Arachnid ( Phylum: Arthropoda; Class: Arachnida)

Cephalothorax Abdomen Mouthparts 4 Pairs of legs Characteristics of an Arachnid ( Phylum: Arthropoda; Class: Arachnida) Simple eyes

Prevent Disease, Disability and Premature Death Arthropod Life Cycles Arthropods develop from one life-stage to another through a process called Metamorphosis Arthropods develop from one life-stage to another through a process called Metamorphosis Metamorphosis: (Greek) A change in physical shape or form Metamorphosis: (Greek) A change in physical shape or form An arthropod’s exoskeleton does not expand as it grows, so it must shed it. This process is called “molting.” An arthropod’s exoskeleton does not expand as it grows, so it must shed it. This process is called “molting.”

Prevent Disease, Disability and Premature Death Arthropod Life Cycles: Metamorphosis Takes place in 1 of 4 ways: (Ametabolous): simple development; immatures and adults look alike Without Metamorphosis (Ametabolous): simple development; immatures and adults look alike (Hemimetabolous): immatures develop in freshwater Incomplete Metamorphosis (Hemimetabolous): immatures develop in freshwater (Paurometabolous): immatures resemble adults with some differences Gradual Metamorphosis (Paurometabolous): immatures resemble adults with some differences (Holometabolous): immatures look completely different from adults Complete Metamorphosis (Holometabolous): immatures look completely different from adults

Gradual Metamorphosis Gradual Metamorphosis Adult Egg Nymphs Larva* * - select arthropods (i.e. ticks, mites)

Complete Metamorphosis Complete Metamorphosis Pupa Adult Egg Larvae

Prevent Disease, Disability and Premature Death Impact of Arthropods and Pests Beneficial arthropods The majority of them are beneficial Some pollinate crops Some produce useful products: honey and silk Some kill or control pests

Prevent Disease, Disability and Premature Death Impact of Arthropods and Pests Problem arthropods Destroy field crops Destroy wooden structures Destroy stored food products Create nuisances Spread diseases and cause direct effects on health

Prevent Disease, Disability and Premature Death Summary Arthropod Anatomy Arthropod Life Cycles Impact of Arthropods & Pests

Prevent Disease, Disability and Premature Death Questions?سوالات