The Wonderful World

of Insects

Field Natural History

Diagnostic Features, Ecology, and

Economics of Insect Orders

Videos of Interest

• Leaf Cutter Ants • http://www.youtube.com/watch?v=RH3KYBMpxOU

Songs of Insects

Beetle Flight

http://www.youtube.com/watch?v=fC61ZA4uWbs

Class Insecta

• Most abundant animal group—approximately 30% of animal biomass—possible 10 million species

• Ecologically and Evolutionary Diverse – Rapid reproduction (short generation time and great fecundity)

– Rapid adaptation to new environments (overcome chemical warfare)

– Small and agile

• Agricultural and Human Pests – Disease transmission

– Crops destruction

Songs of Insects

Insect Natural Resources

• Pest Management

– Crop protection

• Pollination

– Human nutrition

• Materials

– Silk

– Honey

– Confectioner’s glaze

– Cochineal

Characteristics of Insects

• Insects as Arthropods – Jointed appendages

– Chitinous flexible exoskeleton

– Complex mouth parts

– Three primary body structures

– Segmented body parts

– Generally with six legs, • one pair of antennae, and

• two pairs of wings

– Complete metamorphosis

Insect Orders approximately 1.5 million species named

• Coleoptera (beetles) 370,000

• Lepidoptera (butterflies, moths) 150,000

• Hymenoptera (bees, wasps, ants) 120,000

• Hemiptera (true bugs) 100,000

• Diptera (flies, mosquitoes) 100,000

• Orthoptera (grasshoppers) 20,000

• Odonata (dragonflies) 5,000

• Ephemeroptera (mayflies) 2,000

Diptera—True Flies

• Two-winged insects

• Hind wings modified into halteres which have a role in flight stability

• Large eyes

• Relatively short antennae compared with bees

• Mosquitoes, gnats, and flies

• Diverse ecological roles

– Parasites and disease vectors

– Blood suckers

– Decomposers

– Few pollinators

Diptera—True Flies

Many species of flies mimic

various hymenoptera—note the

short antennae, lack of abdominal

constriction, and one pair of wings

Hymenoptera—

Bees, wasps, and ants • Membrane-winged insects

• Four wings with 2nd pair smaller than 1st pair

• Distinct constriction between thorax and abdomen

• Ecology

– Few parasites on other insects

– Important pollinators of crops

– Some gall forming insects

• Navigational behaviors

– Ants spatial sensitivity

– Bees and sun compass

Ants as farmers, seed dispersers, and protectors

Hymenoptera-Leaf Cutter Ants

An Incredible Example of Coevolution

Social division of labor

Fungus farmers

Sensitivity to needs

of cultivated fungi

http://www.youtube.com/watch?v=RH3KYBMpxOU

Many spring ephemerals

have ant dispersed seeds.

Parasitic Wasps

Hymenoptera—

Important Pollinators

• Crops—almonds, alfalfa, apples, apricots, blackberries, blueberries, cherries, citrus, clover melons, peaches, plums, raspberries, strawberries, squash, tomatoes,

• Hundreds of Millions of dollars in bee services

• Honey and Beeswax production – Orange blossom honey

– Sourwood honey

• European Honey Bee Introduction and Impact on Native Bumble Bee Ecology

Bee Pollination & Human Health

Anti-bacterial Anti-cancer

Minerals

Vitamins

Anti-oxidants

Spices

Anti-aging

Honey is Liquid Gold

To make 1 lbs. of honey

– The colony must visit 2 million flowers

– Travel 45-55,000 miles

– Work 4000 bee hours

• Travel cost-$0.40/mile

– $20,000

• Minimum Wage

– $29,000

• Total = $49,000

Bee Society

Workers

--caretakers, foragers,

honey makers

--female—skilled

communicators,

navigators, and providers

Queen

--one per hive

--egg layer

--phermones regulation

Drones

--fatherless males

--sole purpose—sex

--go out with a bang

Hollywood Violates the Rules of Nature

www.beemovie.com

Language of the Honeybee

Distance from Hive

Waggle Frequency

Language of the Honeybee

NEAR

FAR

Direction from Hive

Relative to Sun

Language of the Honeybee

Hemiptera- True bugs (half wing)

• Half of forewing is thickened and leathery

• Enlarge pronotum extending along dorsal abdomen

• Wings cross over the abdomen forming an “X” pattern

• Piercing, sucking mouth parts—plant pests – Milkweed bugs

– Stink bugs

– Boxelder bugs

• Some species predaceous – Assassin bugs

– Ambush bugs

– Water boatmen

Today’s Natural Moment contributed by Katie W.

What are the red streaks

on this maple (Boxelder)?

Hemiptera

Lepidoptera-Scale-winged Insects • Wings covered in minute,

square-shaped scales

• Large knob-like or feather like antennae

• Division into moths and butterflies is somewhat artificial

• Larvae-caterpillars

• Ecology – Larvae are herbivorous

– Adults short-lived, nectar feeders

– Migratory behavior

• Coevolved with Plant Host – Milkweeds and monarchs

– Fritillaria with violets

• Economics – Silk

– Butterfly gardening

– Pollination--vanilla

Lepidoptera

Silk worm moth feeding

on mulberry leaves Urticating hairs on IO moth caterpillar

Coleoptera—

Sheath-winged Insects • Most abundant insects—

species numbers (1 in 4 animal species)

• 1st Pair of wings (elytra) thickened and protective often colorful and irridescent

• 2nd pair are membranous and used for flight

• Largest insect—Acteon Beetle of South America (9cm x 5 cm)

http://www.youtube.com/watch?v=fC61ZA4uWbs

Beetle Bark Galleries

Elm & Pine

Elm bark beetles also transport the fungus that causes Dutch Elm disease

Weevils are Beetles

Coleoptera—Interesting Beetles

• Lightening Bug

– Enzymatic luminescence for mating

– Coevolved predation

• Blister and Bombardier beetles

– Abdominal chambers mix quinones, hydrogen

peroxide, and oxygen to produce an audible

and caustic explosion for protection

– Cantharidin is a chemical from blister beetles that can be

purchased to help remove warts.

http://www.flickriver.com/places/United+States/Vermont/Shelburne/

Odonata—

Dragonflies and Damselflies • Four long and similar-shaped

wings

• Elongated abdomen

• Large eyes and short bristle-like antennae

• Predaceous

• Dragonflies-wings held flat

• Damselflies-wings held together above abdomen

• Important in stream food chains

• Mating dynamics

• Migratory behavior

Ephemeroptera—

Short-lived Insects

• Freshwater insects whose

adults live only a single day

• Fragile triangular wings held

above fragile body; 2nd pair of

wings much reduced;

• Elongated abdomen with two

or three cerci

• Important member of stream

ecology

Homoptera—Cicadas, Leafhoppers,

Aphids, Scale Insects, Whiteflies

• Wings elevated in roof-like

posture above body at rest

• Plant feeders—often

specialized on small groups

of plants

• Plant pests and disease

vectors

• Confectioner’s Glaze, Resin

Glaze or Lac Resin

http://www.richard-seaman.com/Wallpaper/Nature/TrueBugs/LeafHopper.jpg

Orthoptera—Grasshoppers,

crickets • Enlarged femur-like segment

of 3rd pair of legs

• Well developed tympana on either abdomen or pair of legs

• Shield-like pronotum on thorax

• Long hair-like antennae

• Crickets with courtship and aggressive songs

• Sounds produced either by wings or femora of hind legs

• Mostly herbivorous, some carnivorous

Songs of Insects

Order Mantodea--Mantids

• Generalist predators

• Front pair of legs

modified into vise-like

structures for

grasping prey

• Female cannibalism

of males not

widespread

http://www.birdwatchersdigest.com/bwdsite/learn/hummingbirds/mantis-hummer.php?sc=migrate

Neuroptera-Lacewings, Fishflies,

Dobsonflies

• Four membranous wings

held roof-like over body,

many veined

• Long thread-like

antennae extending

dorsally over thorax and

abdomen

• Predators of other

insects, beneficial aphid

predator

• Aquatic larvae—fish flies

• Attracted to night lights

http://biokeys.berkeley.edu/inverts/images/insecta/drawings/neuroptera.jpg

Order Neuroptera—Fishflies,

Dobsonflies and Lacewings

• Net-like pattern of

wing veins

• Long antennae and

large wings

• Insect predators

• Many important in

stream ecology

Ephmeroptera—

Short-lived Insects

• Freshwater insects

whose adults live only a

single day

• Important member of

stream ecology

• Fragile triangular wings

held above fragile body;

2nd pair of wings much

reduced;

• Elongated abdomen with

two or three cerci

Order Dermaptera--Earwigs

• Nocturnal scavengers

and herbivores

• Hooked cerci

• Never found in ears

http://www.life.illinois.edu/entomology/illustrations/gifs/dermaptera.gif

Order Thyansoptera--Silverfish

• Common in moist, dark,

human dwellings

• Consume and digest both

CELLULOSE and starch

• Flattened bodies, tapered

abdomen, small eyes

• “bookworms”

http://insectphotos.net/orders/thysanura/images/silverfish1.jpg