DICHOTOMOUS KEYS Based on dichotomies, you must choose one of two options By repeating this step, you can narrow down to more and more specific classifications Answers often involve whether a diagnostic trait is present Example: Does this insect have wings?

Does it have cerci (tails?)

ODONATA Does it have a stout body and hold its wings flat at rest? Is Body Longer than Wingspan? Do its eyes touch at top of head? Odonata Anisoptera Dragonfly Gomphidae Clubtails Aeshnidae Darners Libellulidae Skimmers Zygoptera Damselfly Lestidae Spreadwings Coenagrionidae Narrow Winged

HOW THE KEY WOULD LOOK 1.It has wings4 It doesn’t have wings2 2.It has six legs3 It doesn’t have six legsit’s not an insect 3.Its ancestors have wings4 It never had wingsapterygota 4.It only lives for a dayephemeroptera It lives for many days5 5.It has bulging eyesZygoptera Its eyes do not bulgeAnisoptera

FRUIT KEY EXERCISE

ORDER BLATTODEA: ROACHES What makes a cockroach? Cockroaches Are not the same as beetles!!! Distinguished by ‘hood’. Extension of pronotum covering head. ‘Dorso-ventrally’ flattened… Usually brown drab color Cylindrical egg sack, attached to female’s posterior Have functional wings, but rarely fly Two short cerci Long thin antennae

EW? Only a few are pests Most cockroachs feed on decaying wood, fruit, and other plant matter Cockroaches are very important decomposers Take plant matter and make it into food for other critters However, some cockroaches (American roach, Oriental roach especially) are icky Tend to invade homes Do NOT spread disease… But eat and spoil foodstuffs Also, these species smell bad