Download Entomology--Michael Meyer

Entomology for the Masters
- A brief history
- Insect overview
- Order recognition
- Identification activity
- Insect evidence
- Friend and foe
Michael Meyer, Ph.D.
Dept. Organismal and Environmental Biology
Christopher Newport University
John Henry Comstock - the first entomology instructor
Comstock  Traver  Edmunds  McCafferty  Meyer
What’s not an insect [or “bug”]?
Class: Arachnida (arachnids)
Order: Opiliones (harvestmen)
- single body segment
- predators; scavengers of animals and plants
- repellent secreted as defense
Class: Arachnida (arachnids)
Order: Acari (mites, ticks, chiggers)
- variety of life histories
- predators, herbivores, parasites, suspension feeders
- terrestrial and aquatic (fresh and salt water)
- may be vectors of disease
Class: Arachnida (arachnids)
Order: Araneae (spiders)
- poison = protein-digesting
- fangs are distal portion of chelicerae
- spinnerets and silk (six main kinds) production
Class: Diplopoda [millipedes]
- generally cylindrical
- 2 pair of legs on body segments
- slow; feed on plants or decaying
materials
Class: Chilopoda [centipedes]
- flattened; one pair of legs on body segments
- fast: predators, feed on insects/other arthropods
- poison jaws paralyze prey
Why should “we” study entomology?
Why should we study entomology?
1. Insects are the dominant group of animals.
- the Earth’s most varied organism
- 80% of all known animals, 57% of all life
- >1 million described species [54K vertebrates]
2. Many insects are valuable to us.
- produce goods (i.e., honey, silk), services (i.e.,
pollination, pest control), and food (i.e., fruits, vegetables)
- research animals (i.e., Drosophila, bomb-sniffing wasps)
3. Some insects are harmful.
- destroy crops, animals, and possessions
- transmit human disease
- just plain annoying
4. Insects are fascinating/interesting.
- beautiful, fascinating organisms
- used throughout human culture/history
Why are insects so successful?
Factors in the success of insects.
1. Highly adaptable exoskeleton.
-
legs suited for locomotion on land and in water
-
tracheae system for respiration
-
wax covering to reduce the loss of moisture
2. Colonization of the terrestrial environment before
chordates.
- Early Devonian (410 MYA) = first fossil record
- Early Jurassic (200 MYA) = therians (early mammals)
3. Small body size.
- occupy an enormous variety of small places
4. High birthrate and short generation time.
- little time to grow to maturity (due to small size)
- increased potential for genetic change in populations
5. Highly efficient flight.
- escape unfavorable habitats and colonize new ones
- escape enemies, find food, mates, places to oviposite
6. Life history with metamorphosis.
- reduced competition between larvae and adults
- larvae utilized food inaccessible to adults
Generalized Body Regions
Head
- mouthparts
Wings
Wings
- generalized [membranous] [dragonfly]
Wing modification
Wing modification
- elytra [beetle]
Wing modification
Wing modification
- hemelytra [true bug]
Wing modification
A Blan
Wing modification
- tegmina [roaches and “songsters”]
A Blan
Wing modification
Wing modification
- halteres [true flies]
Abdomen
Abdomen
Aphids: cornicles
Abdomen
Abdomen
Earwig: modified cerci
How well do you know the insect Orders?
Ephemeroptera [for a day wings] (Mayflies)
- larvae are aquatic
- subimago life stage
- adults w/ vestigial mouthparts
- adults w/ two or three long “tails”
Odonata [tooth] (Dragonflies and Damselflies)
- larvae are aquatic, w/
prehensile labium
- wings held perpendicular
or parallel to body
- predators; catch basket
- live 3/4 weeks [damsel],
6/10 weeks [dragon]
Orthoptera [straight wings] (Grasshopper, Crickets, and Katydids)
- generally with modified hind legs
- thickened forewings called tegmina
- many are musicians
- most are plant feeders [i.e., pests]
Phasmatodea [small phantom] (Walking Sticks)
- camouflaged, stick-like body
- elongate thorax; reduced or absent wings
- eggs scattered on ground [dropped from trees]
Dermaptera [skin wings] (Earwigs)
- modified cerci: female strait, male curved
- reduced forewings [winged] or wingless
- antennal segments increase with molts
- nocturnal, most feed on plant matter
Isoptera [equal wings] (Termites)
- multiple casts: queen, king, workers, soldiers
- cellulose eating; many with symbiotic protozoan
- often referred to as “white ants”
Mantodea [soothsayer] (Mantids)
- can move head capsule
- modified forelegs with elongate spines
- overwinter as eggs in ootheca [200+ eggs]
- many species in US are introduced
Blattodea [cockroach] (Cockroaches)
- oval, flattened; cursorial
- leathery forewings [tegmina]
- head concealed by pronotum
- egg capsule [ootheca]
- primarily tropical; annoying
Hemiptera [half wings] (True Bugs,
Cicadas, Hoppers, Whiteflies, Scales)
- piercing-sucking mouthparts
- huge diversity: body form, wings, antennae
- predators, herbivores, parasites: may be vectors
Coleoptera [sheath wings] (Beetles)
- modified forewing [elytra]
- rule the world (by numbers); 30,000 species in NA
- tremendous variation of habitats and life history strategies
Neuroptera [nerve wings] (Alderflies, Lacewings,
Antlions, Owlflies, etc.)
- soft bodied, wings with many crossviens
- larvae and adults predaceous; diverse
Hymenoptera [god of marriage wings] (Sawflies,
Wasps, Ants, Bees)
- many have slender waist [pedicel]
- many social; most important pollinators
- hugely beneficial (i.e., predators, parasitoids)
- ovipositor modified into a sting [some]
Lepidoptera [scale wings] (Butterflies, Skippers, Moths)
- scales cover wings, body and legs
- variety of antennae; coiled proboscis
- 11,500 species in NA; can be plant pests
- some with tympanum to detect bat echolocation
Mecoptera [long wings] (Scorpionflies)
- 9-25 mm in length; known as snow fleas
- male genitals similar in appearance to scorpion sting
- many extant families/genera found in fossil record
Diptera [two wings] (Flies, Midges, Mosquitos)
- modified hind wings [halteres]
- great diversity of natural history strategies; many
are pests; vector of many diseases
- variety of mouth types
Identification Activity
Can you identify each of the insect Orders?
Insect evidence and plants. Why plants? What gets eaten?
Insect evidence.
- leaf chewers [Coleoptera and Orthoptera]
Insect evidence.
- leaf miners [Diptera]
Insect evidence.
- fruit and flower feeders [Diptera and Hymenoptera]
Insect evidence.
- sap suckers [Hemiptera and “Homoptera”]
Insect evidence.
- gall makers [Diptera and Hymenoptera]
Insect evidence.
- stem and twig damagers [Orthoptera and “Homoptera”]
Insect evidence.
- trunk and branch borers [Coleoptera]
Insect evidence.
- root and bulb feeders [“Homoptera”]
Plant foes.
Plant foes.
A. Caterpillars [Lepidoptera]
Plant foes.
Plant foes.
B. Beetles [especially weevils; Coleoptera: Curculionidae]
Plant foes.
Plant foes.
C. Yellow jackets [Hymenoptera: Vespidae]
Plant foes.
D. A plethora of sapsuckers
Plant foes.
Plant foes.
D1. Aphids [Hemiptera: Aphidae]
Plant foes.
Plant foes.
D2. Psyllids [Hemiptera: Psyllidae]
Plant foes.
Plant foes.
D3. Mealybugs [Hemiptera: Pseudococcidae]
Plant foes.
Plant foes.
D4. Scale insects [many: Hemiptera]
Plant foes.
Plant foes.
D5. Leafhoppers, treehoppers, spittlebugs [Hemiptera:
Cicadellidae, Membracidae, Cercopidae]
Plant foes.
Plant foes.
D6. Stinkbugs [Hemiptera: Pentatomidae]
Plant foes.
Plant foes.
D7. Lace bugs [Hemiptera: Tingidae]
Plant friends [predators].
Plant friends [predators].
Lady bird beetles [Coleoptera: Coccinellidae]
Plant friends [predators].
Plant friends [predators].
Ground beetles [Coleoptera: Carabidae]
Plant friends [predators].
Plant friends [predators].
Rove beetles [Coleoptera: Staphhylinidae]
Plant friends [predators].
Plant friends [predators].
Fireflies [Coleoptera: Lampyridae]
Plant friends [predators].
Plant friends [predators].
Lacewings (larva) [Neuroptera: Chrysopidae]
Plant friends [predators].
Plant friends [predators].
Lacewings (adult) [Neuroptera: Chrysopidae]
Plant friends [predators].
Plant friends [predators].
Hover flies [Diptera: Syrphidae]
Plant friends [predators].
Plant friends [predators].
Stink bugs [Hemiptera: Pentatomidae]
Plant friends [predators].
Plant friends [predators].
Assassin bugs [Hemiptera: Reduviidae]
Plant friends [predators].
Assassin bugs [Hemiptera: Reduviidae]
Plant friends [predators].
Plant friends [predators].
Mantids [Mantodea: Mantidae]
Plant friends [predators].
Plant friends [predators].
Ants [Hymenoptera: Formicidae]
Plant friends [predators].
Plant friends [predators].
Paper wasps [Hymenoptera: Vespidae]
Plant friends [predators].
Plant friends [predators].
Yellow jackets [Hymenoptera: Vespidae]
Plant friends [parasites].
Plant friends [parasites].
Tachinid flies [Diptera: Tachinidae]
Plant friends [parasites].
Plant friends [parasites].
Ichneumonids and Braconids [Hymenoptera:
Ichneumonidae and Braconidae]
Plant friends [parasites].
Many small wasps [Hymenoptera]
Thank you very kindly!