ENTOMOLOGY Master Gardeners

Emily JustusMarch 29th 2019

Outline

• Taxonomy• Overview• Insect Relatives• Insect Biology and body plans• Insect Orders• Break

• Insect roles• Decomposers• Predators and parasitoids• Pollinators• Pests• Vectors of plant diseases

What is taxonomy?

• Taxonomy: branch of science concerned with classification of organisms.

• Father of taxonomy: Carl Linnaeus (1758)• Published Systema Naturae which based on

binomial method of naming organisms• Carl Alexandar Clerck was the FIRST to use

this system not Linnaeus! He used it to name spiders

• This system is still used today and is regulated by the International Code of Zoological nomenclature

Hierarchy of classification

Kingdom

Phylum

Class

Order

Family

Genus

Species

Hierarchy of classification

Kingdom: Animalia

Phylum: Arthropoda

Class

Order

Family

Genus

Species

Phylum: Arthropoda

• Arthro= jointed

• Poda= feet

• Characteristics:1. Segmented bodies

2. Jointed appendages

3. Exoskeleton

4. Bilateral symmetry

5. Open circulatory system

Class of Arthropoda: Chilopoda

• Centipedes

• One pair of antennae

• One pair of legs per segment

• Venomous

• Predominantly carnivorous

Class of Arthropoda: Diplopoda

• Millipedes

• One pair of antennae

• Two pairs of legs on each segment

• When they hatch they only have six legs!

• Detritivore or herbivores

Class of Arthropoda: Crustacea

• Majority of species are aquatic with one exception- the pillbug or rollie-pollie

• Isopods (order of Crustacea)❖Seven pairs of jointed legs

❖Flattened body that may or may not roll up in a ball

❖Females carry their young in a pouch on their thorax

Class of Arthropoda: Arachnida

• No antennae

• Only two body segments:• Cephalothorax• Abdomen

• Eight legs

• Includes• Spiders• Scorpions• Ticks• Mites• Harvestman

Class of Arthropoda: Arachnida

• No antennae

• Only two body segments:• Cephalothorax• Abdomen

• Eight legs

• Includes:• Spiders• Scorpions• Ticks• Mites• Harvestman• Horseshoe crabs???

Class of Arthropoda: Arachnida

• No antennae

• Only two body segments:• Cephalothorax• Abdomen

• Eight legs

• Includes• Spiders• Scorpions• Ticks• Mites• Harvestman• Horseshoe crabs???

What makes an insect an insect?

What makes an insect an insect?

• One pair of antennae

• Adult have six legs

• Three body segments

What makes an insect an insect?

• One pair of antennae

• Adult have six legs

• Three body segments

What makes an insect an insect?

• One pair of antennae

• Adult have six legs

• Three body segments

Types of mouth parts

• Types of the mouth parts, or even the presence of mouthparts can help you narrow down what insect you have!

Sucking mouthparts Lapping Sponging Chewing

Types of antennae

Just like mouthparts antennae can give you a clue as to what

insect you have!

Types of legs

• Cursorial

• Raptorial

• Saltatorial

• Natatorial

• Fossorial

Types of legs

• Cursorial= running

• Raptorial= grasping

• Saltatorial= jumping

• Natatorial= swimming

• Fossorial= digging

What kind of legs does this insect have?

Types of metamorphosis

• Hemimetabolous

• Partial metamorphosis

• There is not a total rearmament of the body plan, just gradual changes until maturity

• Immature stage: Nymph

• If wings are present, nymphs will have wing pads in the place of adult wings

Types of Metamorphosis

• Holometabolous

• Complete metamorphosis

• Goes through four different life stages• Egg

• Larva

• Pupa

• adult

Insect orders: Overview

• There are roughly 30 orders of insects

• The most species rich are:❖Coleoptera

❖Hymenoptera

❖Diptera

❖Lepidoptera

❖Hemiptera

Hemimetabolous Orders

Insect orders: Phasmatodea

• Walking sticks

• Chewing mouthparts

• Hemimetabolous

Insect orders: Phasmatodea

• Walking sticks

• Chewing mouthparts

• Hemimetabolous

• Some species look like leaves

Insect orders: Phasmatodea

• Walking sticks

• Chewing mouthparts

• Hemimetabolous

• Some species look like leaves

• This group contains the longest insect in the world

Insect order: Mantodea

• Raptorial forelegs

• Chewing mouthparts

• Hemimetabolous

• Egg sac: Ootheca

Insect order: Blattodea

• Cockroaches and Termites

• Chewing mouthparts

• Spectrum of sociality

• Hemimetabolous

• Egg sack: Ootheca

Insect Order: Orthoptera

• Straight wing

• Crickets, grasshoppers, katydids❖Katydids have a sward-like ovipositor

• Long leathery top wings

• Chewing mouthparts

• Weird example: Mole cricket

Insect order: Hemiptera

• Stink bugs, cicadas, aphids, plant hoppers, etc.

• Hemimetabolous

• Piercing-sucking mouthparts

• Herbivores, predators, blood-feeding

• Consists of two groups:❖Hemipterans with hemi-elytra

forewings❖Hemipterans with no wings or

completely membranous wings

Aphid Parthenogenesis

Holometabolous Orders

Insect Order: Thysenoptera

• Fringed wing

• Thrips

• Rasping sucking mouthparts

Insect Order: Thysenoptera

• Fringed wing

• Thrips

• Rasping-sucking mouthparts

• Herbivore or predator

Insect order: Neuroptera

• Lacewings

• Wings are extremely veiny

• Predatory larvae

• Eggs laid on stalks

Insect order: Lepidoptera

• Scale wing

• Holomatabolous

• Moths, butterflies, and skippers

Insect order: Lepidoptera

• Scale wing

• Holomatabolous

• Moths, butterflies, and skippers

• Most lepidopteran pests are little brown moths

Coddling moth

Corn earworm

Fall armyworm

Insect order: Lepidoptera

• Scale wing

• Holomatabolous

• Moths, butterflies, and skippers

• Most lepidopteran pests are little brown moths

• Larvae: Caterpillar❖Head capsule

❖True legs

❖Prolegs

Insect order: Coleoptera

• Sheathed wing

• Most diverse group of insects

• One pair of membranous wings and one pair of hard sclerotized wings

• Chewing mouthparts

• Holometabolous

Insect order: Coleoptera

• Sheathed wing

• Most diverse group of insects

• One pair of membranous wings and one pair of hard sclerotized wings

• Chewing mouthparts

• Holometabolous

• Larva: Grubs❖Head capsule❖True legs❖No prolegs

Insect order: Hymenoptera

• “Married wing”

• Bees, ants, wasps, sawflies

• Holometabolous

• Two pairs of membranous wings connected by hamuli

• Ovipositor modified into a stinger

Insect order: Hymenoptera

• “Married wing”

• Bees, ants, wasps, sawflies

• Holometabolous

• Two pairs of membranous wings connected by hamuli

• Ovipositor modified into a stinger

• Sawfly larvae have prolegs on every abdominal segment

Insect order: Diptera

• Two wings

• One pair of membranous wings and one pair of halteres

• Variable mouthparts

Insect order: Diptera

• Two wings

• One pair of membranous wings and one pair of halteres

• Variable mouthparts

• Larva: Maggots❖No true legs

❖No head capsule

Insect roles

Decomposers

• Insects are important for the breakdown of dead and decaying organisms❖Largely responsible for crating the

humus that covers the soil

❖Breakdown of wood- especially lignin which is difficult to digest- is done by termites and their wood digesting relatives

❖Important part of the nutrient cycle

The ultimate decomposer: Dung beetles

Predators and Parasitoids

• Many orders contain predators• Coleoptera- Ground beetle

• Hymenoptera- Wasps and ants

• Neuroptera- Lacewings

• Hemiptera- Assassin bugs

• Insects can be predacious at the larval and the adult stages• Larval only: Lacewing larvae

• Larval and adult: Ladybird beetle

Predators and Parasitoids

• Parasitoid: a parasite that will eventually kill its host

• Like predators, there are parasitoids in many orders:• Hymenoptera: Parasitoid wasps

• Diptera: Tachinid flies

• Coleoptera: Staphilinids or rove beetles

• Neuroptera: Mantidflies

Parasitoid Video

Pollination

• One out of every three bites of food are dependent on insect pollination

Pollination

• Generalist vs. specialists

• Generalist example: Honeybee

Pollination

• Generalist vs. specialists

• Specialist example: Yucca moth

Weird Pollinators

• Not only bees and butterflies are pollinators• Wasps

• Flies

• Beetles

Insects as Pests

• Only 1% of insects are true pests• Crop pests

• Structural pests

• Stored grain pests

• Forestry pests

• Disease vectors for both plants and animals

Vectors of Disease

• Insects commonly spread plant diseases as a vector and can also cause a secondary infection

• Examples of insect-borne plant pathogens❖Coleoptera: Stewarts wilt (Bacterial disease of corn)

Vectors of Disease

• Insects commonly spread plant diseases as a vector and can also cause a secondary infection

• Examples of insect-borne plant pathogens❖Coleoptera: Stewarts wilt (Bacterial disease of

corn)

❖Hemiptera: Tomato spotted wilt (Virus Aphids of solanaceous crops)

▪ Aphids spread over 150 viruses!

Vectors of Disease

• Insects commonly spread plant diseases as a vector and can also cause a secondary infection

• Examples of insect-borne plant pathogens❖Coleoptera: Stewarts wilt (Bacterial disease of

corn)

❖Hemiptera: Tomato spotted wilt (Virus Aphids of solanaceous crops)

❖Thysanoptera: Iris yellow spot virus (Virus in Onions)

Vectors of Disease

• Insects commonly spread plant diseases as a vector and can also cause a secondary infection

• Examples of insect-borne plant pathogens❖Coleoptera: Stewarts wilt (Bacterial disease of corn)

❖Hemiptera: Tomato spotted wilt (Virus Aphids of solanaceous crops)

❖Thysanoptera: Iris yellow spot virus (Virus in Onions)

❖Hymenoptera: Mummy berry (Fungal in Blueberries)

Mummy berry disease cycle

Mummy berry disease cycle

Who did this damage?

Who did this damage?

Who did this damage?

Who did this damage?

Questions you need to ask to diagnose insect problems:

• Where did you find it?

• When did you find it?

• What part of the plant is it effecting?

• How many legs does it have?

• What does it’s head look like?