Cucumber mosaic virus: >60 aphid species are capable of transmitting CMV in nonpersistent virus – virus is acquired within 1 min of feeding but can be transmitted within a short duration of time (stylet-borne inoculum)Potato virus Y: aphids can acquire the virus in less than a minute and has to be transported very quickly to a healthy plant in a minute or so. Aphids may retain the virus for 24 h.
Define the problem: Record the normal & abnormal charactersKeep written notes & take pictures (blogging?)Examine entire plant in its ecosystemLook around: is something affecting one plant or a group of plants?Look for patterns:Nature is random!If patterns exist on plant or a group of plants…abiotic problem? (e.g., herbicide injury, storm injury to plants, etc.)Biotic sources affect plants randomly (e.g., insect, diseases)Biotic problems change location between yearsScouting procedure:If you have found the problem, mark the problem area with sticks, garden stakes, tall flags, etc.Familiarize yourself with sampling techniques and sample preparationTake a closer look at plants, uproot plants if feasibleAsk the experts before spending money on control!Delineate time-development:Biotic problems may spread slowly in an area and a pattern may appearAbiotic problems develop faster and patterns are obviousKeep an eye on the marked area and sample frequently to be able to “encounter” the problem (random) Determine the cause of injury:Think broadly >> narrow down to few causes ORUse the process of elimination to arrive at a solutionUse all resources you have to ID insects, many on the webFind the economic threshold: doing nothing is also OK
Trends in FAW population were stronger than BAW seen before. FAW pressures were high in all parts of AL. There were at least two generations detected one month apart of FAW in north central AL. Three peaks could be detected one month apart in south AL along the Gulf Coast. Impact of weather parameters was also stronger on FAW populations than BAW.
Entomology Crash Course for Master Gardener Interns Dr. Ayanava Majumdar Ext. Entomologist, State SARE Coordinator Gulf Coast Research & Ext. Center 8300 State Hwy 104, Fairhope AL 36532 Tel: (251) 331-8416 email@example.com
Entomology Crash Course Objective: opportunity to closely examine insects and understand ecological functions Course lay-out:
Insect Form & Function This sign indicates study of real insect specimen using a digital microscope (Dino-Lite Pro)
Fun Facts about insects Insects have been around for at least 350 million years Over 900,000 described species (75% of all animal 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)
Why are INSECTS so successful? Small size, cryptic in nature Small food requirement Rapid and prolific reproduction Parthenogenesis Grows by molting (control over growth rate) Life stages feed on different substrate
Characteristics of arthropods Segmented bodies and jointed appendages Exoskeleton shed periodically Characteristics Insects: Three body regions (head, thorax and abdomen) Six legs or less or zero (NEVER more!) Grasshopper specimen
Insect Exoskeleton Insects have a cuticle, cuticle has chitin Exocuticle Epicuticle (topmost) Chitin molecules interlink to provide strength! Endocuticle Hard cuticle of a cockroach
Insect Growth Insects need to shed (molt) old skin to grow in size. The period between molts is called an instar. Most insects have 4–8 instars before becoming adult. Cicada nymph molts into an adult
Insect Growth Metamorphosis:drastic change in shape and form for growth and development. Two types: complete and incomplete. The stage of development of an insect will affect insecticide efficacy:
Complete metamorphosis EGG ADULT LARVA (mobile stage) PUPA WHAT COULD BE THE ADVANTAGES OF THE LIFE STAGES?
Incomplete metamorphosis WHAT COULD BE THE ADVANTAGES OF THE LIFE STAGES?
Insect mouthparts Insects can be classified according to mouthparts TYPE 1. Chewing Mouthparts:
Coleoptera (beetles,weevils) Some insect have defense markings (click beetle) Mexican bean beetle Vegetable weevil Wireworms
Facts about beetles (Coleoptera) Characteristics: forewings are hard, hindwings are membranous, 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 as adult or larva Beetle wings
Facts about flies (Diptera) Characteristics: good flier (one pair of wings), larva (maggots) with reduced head Have four life stages – egg, larva, pupa, adult Larva have mouth hooks to scrape root surface Adult flies feed on nectar or solids (sponging mouth type) Often overwinter in larval stages Fly wings
Facts about true bugs (Hemiptera) Characteristics: wings are partially hardened, antennae short Some are beneficial species Have three life stages – egg, larva (nymph), adult Overwinter in adult stage – immatures are vulnerable to predation. Piercing-sucking mouthparts Stink bug wings Predatory stink bug
Identifying larvae by appendages Anal prolegs Thoracic legs Abdominal prolegs Normal number of prolegs = 4 (cutworms, armyworms) < Number of prolegs = 3 (green cloverworm) Number of prolegs = 2 (cabbage looper) >>
Facts about moths & butterflies Complete lifecycle – egg, larva, pupa, adult Larvae are damaging stages… Some members have become insecticide tolerant (diamondback moth, corn earworm) Try controlling these pests in early stages (small larva) Head of butterfly showing siphoning mouthparts (coiled beak)
Facts about grasshoppers Life stages: egg, nymph, adult Damage is caused by overlapping generations Damage intense in dry years Eggs laid in clusters in soil, food for many natural enemies Extremely migratory and have unique behavior patterns (e.g., infections) Grasshopper ovipositor
Thysanoptera (thrips) Tobacco thrips Actual size = 5 mm Flower thrips
Facts about thrips Actual size = 5 mm, commonly seen on flowers Life stages: egg, larva, prepupa, pupa, adult Damage is caused by the rasping MP Damage intense in dry years Transmit diseases between plants
Types of Insect Injury Presentation + Simulated training
First know the definitions… INJURY DAMAGE Damage = injury + economic loss
Plant injury by INSECTS Direct injury caused by feeding: chewing mouthparts VS. sucking mouth parts
Plant injury by INSECTS Direct injury caused during oviposition: dimpling on tomato by thrips egg-laying Image: UFL IFAS Ext. Image: UFL IFAS Ext.
Plant injury by INSECTS Indirect injury from insect products: honeydew causes sooty mold (aphids, whiteflies) Image: TopTurf.net Image: Iowa State
Plant injury by INSECTS Injury from disease transmission: aphids, thrips Transmit tomato spotted wilt virus (TSWV) Transmit cucumber mosaic virus (CMV), potato virus Y (PVY) Images: U Wisconsin & Queensland Govt., Australia
Is it really an INSECT injury? General steps to diagnosis:
Define the problem
Look for patterns: abiotic problems have patterns!
*L. Gianessi, 2009. Crop Protection Research Institute.
IPM in home & garden Remove abiotic stresses Conserve natural enemies (habitat) Correctly identify insect pest Biological control agents (microbials) Cultural tactics – variety, rotation, trap crop Chemical insecticides Correct insecticide delivery system: correct application rate, timing, coverage
NE Conservation System Grassy buffers Grassy buffer zone in permanent ecosystems Grass shelters natural enemies Many night-feeding insects hide in grass during day…treat the edges! Sample in grass and keep it under control Grassy buffer zone in temporary agroecosystem
Trap cropping arrangements Perimeter Trap Cropping Trap crop (squash) Trap crop = early planted squash, apply insecticide on borders Squash lured away 66% cucumber beetles and 90% squash bugs (USDA res.) Main crop (watermelon, cantaloupe, cucumber)
Trap cropping arrangements Row Trap Cropping (contd.) Plant trap crop (alfalfa) in rows within the main crop (strawberry) & a using vacuum! Strawberry production in California Strawberry (34 rows) Strawberry (34 rows) Western tarnished plant bug damage Alfalfa
Recommendations for trap cropping Try it on a small scale to gain confidence Integrate with biological/chemical i-cides, pheromone trapping, etc. Trap cropping can manage 1-2 insect species Works great against sucking pests (plant bugs) and slow fliers (beetles) Spray only the trap crop…reduce cost
Alternative Insecticides for Gardeners Use them in rotation: Thuricide, Dipel (Bt) M-pede (soap) Safer pyrethrin Oils (with caution!) Contact a nursery for supplies & purchase early Do not use unlabeled insecticides (e.g., RTU home pesticides) Always read the label!
Toxicity of Some Insecticides (General Use Pesticides) Ref.: “General use insecticides for home gardening” by Dr. RicBessin (UK) Rule 1: Higher the LD50 safer will be the product! Rule 2: Products containing highly toxic AI have very low % chemical.
Decision making in IPM… Insect detection & monitoring Insect identification Population pressure Economic threshold Make treatment decision Choosing right insecticide
What are insect pheromones? Pheromones are chemicals released into environment in small amounts by insects. Pheromones are species specific, stimulates opposite gender. Male moths detect pheromones with antennae. Synthetic sex pheromones are manufactured & used as lures.
Types of Insect Traps Passive traps: do not use a lure of any kind, e.g., pit-fall traps, ground sticky traps, water traps, flight interception trap (beat sheet) Interception trap (can be used with or without light) Pit-fall trap with a metal sheet as hood
Types of Insect Traps Active traps: use a lure of some kind, e.g., food, color, shape, light…PHEROMONES Dome Fly Trap with liquid bait for mass trapping fruit flies Light trap
Types of Insect Traps Active traps (contd.): use a lure of some kind Use many traps for accuracy Active/passive trap: yellow water pan trap Yellow/white Sticky Trap with grid Ball trap for dipteran flies
Why use pheromone traps? Know what to scout for & when to scout INTENSIVELY Automatic identification of closely related species Prediction models will be avail. Stink bug trap Wing trap Pherocon trap Bucket trap
Parts of a Pheromone Trap Metal support Top section (fixed) Lure with lure holder Bottom section (replaceable sticky card with grid) Wing Pheromone Trap
Types of Pheromone Traps Wing Traps Simple wing trap with grid on sticky bottom Wing trap with baffles (large trap surface) Popular due to easy assemblage, large trap area, & low cost Suitable for larger moths: armyworm, cutworm, fruitworms Problem: weather & animals could ruin trap
Types of Pheromone Traps Delta Traps >> Delta traps with sticky insert having a printed grid. Sides fold to hold the sticky insert in place. Advantages: easy assemblage, low maintenance, less interference Suitable for small moths – diamondback moth, warehouse pests Problem: small trapping surface
Types of Pheromone Traps Mass trapping kits Advantages: Relatively inexpensive Convenient cleaning Lure lasts longer Disadvantages: Needs a killing agent (“No Pest Strip”)
What is it? HINT: Several outbreaks of these insects occurred in AL, 2009 Beet armyworm, Spodoptera exigua Fall armyworm, Spodoptera frugiperda
Fall armyworm Insect density (overall) per site 20 17 Monthly average activity (statewide) 19 29 15 27 32 16 12 13 48 36 Year 2009
What are these? Tomato fruitworm, Helicoverpazea Tobacco budworm, Heliothisvirescens
Corn earworm Insect density (overall) per site 6 3 17 Monthly average activity (statewide) 10 8 25 3 12 7 5 8 16 11 Year 2009
Impact of Weather on Trap Catches Sign. Correlation of TEMPERATURE : Year 2009 Sign. Correlation of RAIN DAYS : Numbers indicate significant correlations at P = 0.10. +/- indicates direction of relationship (preliminary findings). Rain days indicate number of days rainfall exceeded 0.1 inch.
Biological Control Agents Asian citrus psyllid: has many natural enemies
General predators Lacewings: Chrysoperla rufilabris
General predators Ash-gray lady beetle, Olla v-nigrum Multi-colored Asian lady beetle, Harmonia axyridis Spotless lady beetle, Cycloneda sp.
IPM in Vegetables:Tomato (Applied Entomology: insect biology meets insect control)
What is it? Monitoring/scouting techniques: Sample ten plants in several locations Yellow sticky traps at edge of field Like cool, dry weather Watch for ants and lady beetles ET = 50% leaves with aphids Potato aphid, Macrosiphumeuphorbiae Green peach aphid, Myzus persicae
What is it? Monitoring/scouting techniques: Use sticky cards (yellow, blue) Bag and shake technique No action threshold Use resistant varieties (BHN 444, 589, 640, Bella Rosa) Western flower thrips, Frankliniella occidentalis Tobacco thrips, Frankliniella fusca Tomato spotted wilt destroys plants
What is it? Monitoring/scouting techniques: Monitor level of defoliation Sample small plants with sweep net during morning hours Observe activity of parasitoids, predators (sweep net) ET = 5-10% defoliation early season, 25-30% defoliation mid-season Flea beetles (many species)
What is it? Colorado potato beetle, Leptinotarsa decemlineata Monitoring/scouting techniques: Start looking on border rows Scout intensely short crop (<6 inch) ET = 5 beetles per 10 seedling or 10% defoliation in short crop Larva of lady beetle (beneficial insect!)
What is it? Monitoring/scouting techniques: Examine green fruit, stem terminals Scout for egg masses or larvae Use pheromone traps to detect first flight; ET = 5-10 moths per night when temp. is <85F ET is ½ if temp. is >85F Tomato fruitworm, Helicoverpa zea Tobacco budworm, Heliothis virescens
What is it? Southern green stink bug, Nezara viridula Monitoring/scouting techniques: Use a sweep net Use pheromone trap (expensive? cumbersome?) Intensify scouting at fruit setting ET = 0.25 bugs per 10 plants (green fruit stage) Lygus bug, Lygus lineolaris Brown stink bug, Euschistus servus
What is it? Monitoring/scouting techniques: Minor foliar pests (ET = 5 larvae per 10 plants) Easy to collect & identify – shake and collect Watch for sun scald on fruits, esp. 20% defoliation Look for fecal pellets on leaves Cabbage looper, Trichoplusia ni Soybean looper, Pseudoplusia includens
Asian Citrus Psyllid(Diaphorinacitri, Hemiptera: Psyllidae)
First Reports of ACP ACP was first detected in 1998 in backyard plantings of Murrayapaniculata At present, 33 counties in FL have ACP ACP has been found in many states, but Citrus Greening Disease (CGD) is present in LO & FL ACP in Baldwin County (2008) No detection of ACP or CGD in 2009 www.SaveOurCitrus.org
ACP Life cycle Host plants: all citrus plants, 2 species of Murraya (all Rutaceae) ACP EGGS Eggs are almond shaped Eggs pale when fresh, turn yellow or opaque Eggs laid on tips of growing shoot or tender leaves in clusters
Life Cycle & Identification NYMPHS 53F* 51F 50F 51F *Liu & Tsai 2000 52F Nymphs: 5 instars, red eyes, large wing pads Development fails below 50oF Live in feeding pits created by adults
Life Cycle & Identification ACP specimen ADULT PSYLLID Adult is 3 mm long, forewings broad apically Tip of antennae black Brown band on wings around the border Wings with reduced venation, prominent veins
Behavior of ACP Auburn Team at a Baldwin County location Active insect that rests with body at an angle Adult psyllids readily jump on approach Dispersion: good fliers, moved by wind
Life Cycle & Identification Defense mechanism: Masses of waxy filaments produced by nymphs to keep honey dew away!
Citrus Injury due to ACP ACP has piercing-sucking mouthparts Loss of plant sap from foliage High reproductive capacity & survival of eggs/nymphs can cause rapid infestation (check new terminals)
Citrus Injury due to ACP (contd.) CITRUS GREENING DISEASE (CGD) or Huanglongbing: Worst disease of citrus transmitted by ACP Bacterium Liberibacter Short feeding inoculates ACP
Citrus Injury due to ACP (contd.) SYMPTOMS OF CGD:
Remember: other disorders may cause diagnostic problems
What can confuse you? Citrus thrips (Scirtothrips citri) Long bristles on wings Citrus mealybug (Planococcus citri) No wing-pads! Trash bug (trash-carrying lacewing) Brown citrus aphid (Toxoptera citricida) Have tail-pipes!
IPM Trapping Coordinators: A. Majumdar H. Fadamiro K. Flanders IPM Team Members: Lloyd Chapman Neil Kelly Michael Reeves Gary Gray James Miles William East, Jr. Brandon Dillard Leonard Kuykendall Chris Becker Timothy Reed Acknowledgements to AL IPM Team Thank you very much. Please take the POST-TEST