Arthropods

Insects and their relatives are ARTHROPODS. What is Entomology? The study of insects (and their near relatives). What are insects (and near relatives)? Insects and their relatives are ARTHROPODS.

Review of Zoological Nomenclature (classifying & naming) Taxonomic Categories KINGDOM Phylum Class Order Family Genus Genus & species

Review of Zoological Nomenclature Taxonomic Categories Kingdom - Animalae Phylum - Arthropoda Class - Insecta Order - Coleoptera Family - Scarabaeidae Genus - Popillia Genus & species Popillia japonica Newman

Characteristics of the Phylum Arthropoda The segmented bodies are arranged into regions, called tagmata (e.g., head, thorax, abdomen). The paired appendages (e.g., legs, antennae) are jointed. They posses a chitinous exoskeletion that must be shed during growth. They have bilateral symmetry. The nervous system is dorsal (belly) and the circulatory system is open and ventral (back).

Arthropod Groups (taxa) The arthropods are divided into two large groups that exist today: Chelicerates and Mandibulates

Chelicerate Arthropod Characters: Pincer-like mouthparts - chelicerae NO antennae Two body regions, usually - cephalothorax & abdomen Four pairs of legs Horseshoe crabs and arachnids are only living groups

Mandibulate Arthropod Characters: Mouthparts are mandibles - normally chewing sideways One or two pairs of antennae Various body region arrangements - cephalothorax & abdomen / head & trunk / head, thorax & abdomen Variable leg numbers Insects, crustaceans & myriapods

Orders of Arachnids Scorpions Pseudoscorpions Daddy Long-Legs Mites & Ticks Spiders

Pseudoscorpion Tick (a mite) Scorpion Wolf Spider Daddy-long-legs

Scorpion Anatomy

chelicerae eyes pedipalp

Pseudoscorpion

American dog tick male Blacklegged (deer) tick female

American dog tick female laying egg mass (1000-2000 eggs!).

Clover mites Twospotted spider mites Predatory mite

daddy long-legs cephalothorax abdomen

Spider Anatomy pedipalp chelicera (fang) cephalothorax narrow waist abdomen

Jumping Spider Abdomen Cephalothorax Chelicera (fang) Pedipalp

Wolf spider with egg case Spitting spider Orb-weaving spider Tarantula

Black widow with egg case Brown recluse

(many legged arthropods) Classes of Myriapods (many legged arthropods) (all have one pair of antennae, a head region, and trunk with many pairs of legs, use trachea) Diplopoda - millipedes Chilopoda - centipedes

Myriapods Millipede (Diplopoda)) Centipede (Chilopoda)) [one pair of antennae, head & trunk regions, trunk with many pairs of legs] Millipede (Diplopoda)) Two pair of legs per visible segment, attached under body. Centipede (Chilopoda)) Pair of fangs under head, one pair legs per visible segment - attached to side of body. No fangs, no eyes, legs attached to side of body.

Millipede (Diplopoda) Centipede (Chilopoda) Garden centipede

Classes of Crustacea Sowbugs or pillbugs Crabs, lobster, shrimp mostly marine, fresh water, a few terrestrial all have two pair of antennae five or more pairs of legs segmented abdominal appendages head & trunk or cephalothorax & abdomen body arrangement have gills Sowbugs or pillbugs Crabs, lobster, shrimp