Insect Orders to Know for Master GardenersPresentation Transcript
Entomology Crash Course for Master Gardeners Dr. Ayanava Majumdar Extension Entomologist Alabama Cooperative Extension System Gulf Coast Research & Extension Center 8300 State Hwy 104, Fairhope, Alabama 36532 Cell phone: 251-331-8416
Entomology Crash Course for Master Gardeners
Objectives & course lay-out:
Techniques for basic insect identification
Practical ways of scouting
Use of monitoring devices
Use of trap crops for sustainable veg. prod.
Discussion on new invasive insects
All presentations will be available on CD or website. … with emphasis on vegetable production
IMPORTANT INSECT PEST ORDERS Dr. Ayanava Majumdar Extension Entomologist Alabama Cooperative Extension System Gulf Coast Research & Extension Center 8300 State Hwy 104, Fairhope, Alabama 36532 Cell phone: 251-331-8416 PART 1
Insects have been around for at least 350 million years
Over 900,000 described species
U.S. has about 91,000 described species
Less than 1% of these are considered pests
Four largest insect orders: beetles (Coleoptera), flies (Diptera), ants (Hymenoptera), moths (Lepidoptera)
In the typical backyard there are >1000 insects at any given time
have exoskeletons, segmented bodies and jointed appendages
exoskeleton must be shed periodically
Three body regions (head, thorax and abdomen)
Arachnids (spiders, mites, ticks):
Two body regions (head and abdomen)
Adults have eight legs
Insects and Their Relatives (Arthropods)
Insects need to shed (molt) their skin (exoskeleton) and produce a new larger one in order to grow.
The period between molts is called an instar.
Most insect life cycle consist of between 4 and 8 instars before they become an adult and stop growing.
Insects can drastically change in shape and form during their growth and development. This is called metamorphosis (change in form).
There are two forms of metamorphosis, complete and incomplete .
The stage of development of an insect will affect way you attempt to manage that insect.
Four distinct growing stages:
Butterflies, moths, flies, beetles, wasps, and bees.
Young resemble adults but without wings
No Pupal stage
Egg -> nymph -> adult
True Bugs, dragonflies, grasshoppers, termites
Coleoptera (beetles,weevils) Mexican bean beetle Some insect have defense markings (click beetle) Wireworms Vegetable weevil
Facts about beetles (Coleoptera)
Characteristics: forewings are hard, hindwings are membranous, long-lived in soil, poor fliers
Have four life stages – egg, larva (grub), pupa, adult
Grubs have strong mouthparts & are root feeders
Beetles (adult) are foliage/flower feeders and may transmit diseases
Often overwinter in adult or larval stage which are tough-skinned
Diptera (flies) Vegetable leafminer Seedcorn maggots Mouth hooks of maggots
Facts about flies (Diptera)
Characteristics: very good flier (one pair of wings), hairy body of adult, larva (maggots) hairless & reduced head, antennae small
Have four life stages – egg, larva (maggot), pupa, adult
Larva have mouth hooks to scrape root surface
Adult flies feed on nectar or solids (sponging mouth type)
Often overwinter in larval stage – tough-skinned maggots
Identifying larvae by structure Thoracic legs Abdominal prolegs Anal proleg Normal number of prolegs = 4 (cutworms, armyworms) < Number of prolegs = 3 (green cloverworm) Number of prolegs = 2 (cabbage looper) >>