Drosophila - Master Gardeners

Entomology for the Masters - a brief history - insect overview - Order recognition - identification activity - plant damage - garden 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

a. hypognathus [herbivore/chewing] b. prognathus [predator] c. opisthognathus [herbivore/sucking]

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

Thysanaptera [fringe wings] (Thrips)

- body range from 0.5-5 mm

- unique, rasping mouthparts - feed on plants; many are vectors - if wingless, then eyeless

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 caused plant damage. What gets eaten?

Insect damage.

- leaf chewers [Coleoptera and Orthoptera]

Insect damage.

- leaf miners [Diptera]

Insect damage.

- fruit and flower feeders [Diptera and Hymenoptera]

Insect damage.

- sap suckers [Hemiptera and “Homoptera”]

Insect damage.

- gall makers [Diptera and Hymenoptera]

Insect damage.

- stem and twig damagers [Orthoptera and “Homoptera”]

Insect damage.

- trunk and branch borers [Coleoptera]

Insect damage.

- root and bulb feeders [“Homoptera”]

Garden foes.

Garden foes.

A. Caterpillars [Lepidoptera]

Garden foes.

Garden foes.

B. Beetles [especially weevils; Coleoptera: Curculionidae]

Garden foes.

Garden foes.

C. Yellow jackets [Hymenoptera: Vespidae]

Garden foes.

D. A plethora of sapsuckers

Garden foes.

Garden foes.

D1. Aphids [Hemiptera: Aphidae]

Garden foes.

Garden foes.

D2. Psyllids [Hemiptera: Psyllidae]

Garden foes.

Garden foes.

D3. Mealybugs [Hemiptera: Pseudococcidae]

Garden foes.

Garden foes.

D4. Scale insects [many: Hemiptera]

Garden foes.

Garden foes.

D5. Leafhoppers, treehoppers, spittlebugs [Hemiptera: Cicadellidae, Membracidae, Cercopidae]

Garden foes.

Garden foes.

D6. Stinkbugs [Hemiptera: Pentatomidae]

Garden foes.

Garden foes.

D7. Lace bugs [Hemiptera: Tingidae]

Garden foes.

Garden foes.

D8. Thrips [Thysanoptera]

Garden friends [predators].

Garden friends [predators].

Lady bird beetles [Coleoptera: Coccinellidae]

Garden friends [predators].

Garden friends [predators].

Ground beetles [Coleoptera: Carabidae]

Garden friends [predators].

Garden friends [predators].

Rove beetles [Coleoptera: Staphhylinidae]

Garden friends [predators].

Garden friends [predators].

Fireflies [Coleoptera: Lampyridae]

Garden friends [predators].

Garden friends [predators].

Lacewings (larva) [Neuroptera: Chrysopidae]

Garden friends [predators].

Garden friends [predators].

Lacewings (adult) [Neuroptera: Chrysopidae]

Garden friends [predators].

Garden friends [predators].

Hover flies [Diptera: Syrphidae]

Garden friends [predators].

Garden friends [predators].

Stink bugs [Hemiptera: Pentatomidae]

Garden friends [predators].

Garden friends [predators].

Assassin bugs [Hemiptera: Reduviidae]

Garden friends [predators].

Assassin bugs [Hemiptera: Reduviidae]

Garden friends [predators].

Garden friends [predators].

Mantids [Mantodea: Mantidae]

Garden friends [predators].

Garden friends [predators].

Ants [Hymenoptera: Formicidae]

Garden friends [predators].

Garden friends [predators].

Paper wasps [Hymenoptera: Vespidae]

Garden friends [predators].

Garden friends [predators].

Yellow jackets [Hymenoptera: Vespidae]

Garden friends [parasites].

Garden friends [parasites].

Tachinid flies [Diptera: Tachinidae]

Garden friends [parasites].

Garden friends [parasites].

Ichneumonids and Braconids [Hymenoptera: Ichneumonidae and Braconidae]

Garden friends [parasites].

Many small wasps [Hymenoptera]

Thank you very kindly!