Download Scientists place living things into groups based on their physical

How are living things
classified?
Scientists place living things into groups based on their
physical, chemical, & behavioral characteristics. This
activity is called classification.
Each type of living thing is called a species and is assigned a unique two-word name in Latin. The
first word is the genus, the second word is the specific epithet. Together they make up the species’
scientific name, as in your name (Homo sapiens) and the monarch butterfly (Danaus plexippus). Closely
related species are assigned the same genus, such as the milkweed butterflies: monarch (Danaus
plexippus), soldier (Danaus eresimus), and the queen (Danaus gilippus). Related species are placed into
other genera. For example, cousins of the milkweed butterflies are the ladies, placed in the genus
Vanessa. Local ladies are west coast (Vanessa annabella), painted (Vanessa cardui), American (Vanessa
virginiensis), and red admiral (Vanessa atalanta).
Milkweed and lady butterflies share many similar characteristics, so we place them into the same
family, Nymphalidae – the brushfoot butterflies. They all have sharp spines (often branched) when in
the caterpillar stage. The adults have very small front legs that are held close to the body, not used for
walking. Female brushfoots use chemical sensors on the tips of their front “toes” to scratch and sample
potential foodplants for their young. If the chemicals in the plant match what she seeks, she lays eggs
on it, then her young hatch from the eggs and feed on the plant.
Similar families are placed into the same order. The members of all butterfly and moth families have 4
wings covered with flat overlapping scales. They also have a long tubular “drinking straw” proboscis.
We place them into the same order, Lepidoptera - butterflies & moths.
Arthropods
Crustaceans
Trilobytes
Spiders
Centipedes
Millipedes
Insects
Mantids
Dragonflies
Grasshoppers
Earwigs
Walkingsticks
True Bugs
Butterflies & Moths
Metalmarks
Swallowtails
Whites &
Sulphurs
Moths
Coppers,
Hairstreaks,
Blues
Skippers
Brushfoots
Scorpionflies
Lacewings
Flies
Beetles
Caddisflies
Ants,
Wasps,
Bees
What is an Arthropod?
An arthropod is a type of invertebrate (boneless) animal
that has these characteristics:
•External skeleton made of chitin (a complex sugar)
•The soft exoskeleton of caterpillars is made only of chitin
•Hard exoskeleton parts also contain protein
•The hardest exoskeletons also contain calcium carbonate
•Body divisions grouped into 2 or 3 major regions, of 3
general types:
•Head - Trunk (centipedes, millipedes)
•Cephalothorax - Abdomen (spiders, scorpions)
•Head - Thorax - Abdomen (insects)
•Paired, segmented, & jointed appendages:
•Antennae (absent in some types)
•Mouthparts
•Leg-like appendages (absent in some types)
•Legs
•Internal features such as:
•Circulatory system that is dorsal & open
•A dorsal brain with a pair of ventral nerve cords
•Respiratory system that takes air in through body
openings, not through the mouth
What is an Insect?
An insect is a type of arthropod that has these
characteristics:
•A life cycle that involves change from young to adult.
In a few types it is only size, some it is size & structure,
others a drastic change.
•Body divisions clearly grouped into 3 major regions:
head, thorax, abdomen.
•The thorax (transportation region) itself has 3 regions:
prothorax, mesothorax, & metathorax. Each region has
2 pairs of legs, for a total of 6 legs.
•Insects are the only invertebrates that have wings,
though some insect groups have no wings.
•When wings are present, they are attached to the second
and third segments of the thorax, for a total of 4 wings
•Some insects have no wings, others have only 2 wings.
What is a Butterfly?
A butterfly is a type of insect that has these
characteristics:
•Complete change life cycle: egg - larva - pupa - adult
•Larva
•A caterpillar with an obvious head, outfitted with biting
mandibles to eat leaves
•Wings that develop inside the caterpillar’s body
•Adult
•Has a long hollow tubular “drinking straw” mouthpart
(proboscis) though which it sucks nectar and water. It is
coiled and stored beneath the head when not in use.
•Four large wings, covered with flat overlapping scales that
are often colorful
•Two long slender antennae that end in a club
•Most butterflies fly in the daytime
What is a Moth?
A moth is a type of insect that has these characteristics:
•Complete change life cycle: egg - larva - pupa - adult
•The pupa is sometimes inside of a silken cocoon
•Larva
•A caterpillar with an obvious head, outfitted with biting
mandibles to eat leaves
•Wings that develop inside the caterpillar’s body
•Adult
•Has a long hollow tubular “drinking straw” mouthpart
(proboscis) though which it drinks nectar and water. It is
coiled and stored beneath the head when not in use.
• Some moths have no proboscis and do not feed!
•Four large wings, covered with flat overlapping scales that
are often colorful. Some moths have no wings!
•Two slender antennae that do not end in a club.
• Some moths have feathery-looking side branches on their
antennae.
•Most moths have heavier, hairier bodies than butterflies
•Most moths fly at night
Where can I find butterflies?
All living things have the same four basic needs: Food,
Water, Space, & Mates. Visit places where butterflies
can get those things and you will find them. Especially
important are places where native California plants thrive
and no pesticides are used.
Try these places:
•Local canyons, hills, & mountains
•Wildlife preserves
•Man-made parks & gardens that have a lot of flowers
and no pesticide use
•Waterways: creeks, streams, ponds
•Hilltops where males wait for females to fly by
•Mountain Ranges: Santa Monica, San Gabriel, San
Bernardino, San Jacinto, Santa Ana, & Laguna
Mountains
•Mojave & Colorado Deserts