1. Chemical control of insects

2. Meaning of insect control
All measures which kill or repel insects interfering with their feeding,respiration,reproduction or dispersal

3. Types of insect control-
A. natural control measure
B. Artificial or applied method-
Chemical control
Biological control
Physical control

4. Chemical Control
Using pesticides or insecticides (chemicals).

5. Chemical Control Contact Poisons
Affect the insect’s nervous system and must come into contact with insect to be effective.

6. Chemical Control Stomach Poisons
Are sprayed on plant surfaces or are taken into the plant through absorption.
Insect must eat or suck the poison to get it into the stomach for this method to be effective.

7. Chemical Control Fumigants
Poisonous gases released into an enclosed place so that insects breathe the gases.

8. Agriculture Pesticide Applications
Boom sprayer
Aerial
Enclosed cab
Backpack wand
Air blast sprayer

9. Pesticide Chemical Families -grouping based on similarities-
Similar chemically (similar structure)
Attacks pests in a similar way (toxicity)
Common treatment + antidote
Pyrethroid PY
Organophosphate OP
Carbamate C
Organochlorine OC
Chlorophenoxy
Paraquat
Diquat

10. Types of insecticide- Normal use: If ingested: High doses:
Pyrethroids: are irritants to the eyes, skin and respiratory tract. The symptoms last from 1-2 hours. Systemic toxicity from inhalation or dermal absorption is low.
Normal use:
Paresthesias (cyno pyrethroids)
Shortness of breath (wheezing)
Mucous membrane irritation (throat nose)
Skin itching
If ingested:
Loss of consciousness/coma
Seizures (cyno-pyrethroids)
High doses:
Vomiting
Diarrhea
Excessive saliva
Muscle fasciculation
Ataxia
Irritability: to sound ~ touch
Cyno-pyrethroids: fenverlate, flucythrinate, fluvalinate cypermethrine, deltapermethrin,

11. Organochlorines: 10 - 480 lipophylic
The nerves stimulating glands are not affected so you will NOT see:
excessive salivation
excessive sweating
excessive eye tearing
(or over-stimulation of small muscles like)
twitching eyelids
CNS Effects
Muscle Weakness
Dizziness
Headache
Numbness
Nausea/vomiting
LOC
Seizures
Tremors
Ataxia
Anxiety/restlessness
Confusion

12. Paraquat dryness, cracks
Paraquat is very toxic to the skin and mucous membranes. Particles are too large to get deep into the lungs*, but once in the blood it collects in the lungs. If ingested high case fatality rate.
Skin:
dryness, cracks
erythema
blistering
ulcerations
Nails:
discoloration
splitting nails
loss of nails
Respiratory tract:
cough
nosebleeds
sore throat
Eyes:
conjunctivitis
ulceration, scarring, blindness
Ingestion:
lung fibrosis (stiff lungs)
multi-system organ failure, specifically
respiratory failure
kidney failure

13. DEET DIETHYLTOLUAMIDE
Few toxic cases - given the widespread use
Toxic if ingested
Children: toxic encephalopathy w/ heavy use on large surface area on kids (+ ETOH - isopropyl or ethyl)
Dermal problems: tingling, irritation, desquamination, contact dermatitis, exacerbate pre-existing skin dz
Kids: use 5-6.5% formulations

14. Boric Acid Ants, Cockroaches in Residences
“broiled lobster appearance”

15. Fluorides
Transformed in stomach to corrosive hydrofluoric acid:  thirst, nausea-vomiting, diarrhea, abdominal pain
Fluoride ion reduces extra-cellular fluid concentrations of Ca+ and Mg  hypocalcemic tetany
Cardiac arrythmias- shock  2ndary to fluid/electrolyte imbalances, hypokalemia and the fluoride itself
CNS  H.A. muscle weakness, stupor, seizures and coma

16. Disadvantage of using chemical control method

17. Biomagnification

18. Bioaccumulation & Biomagnification

19. One other problem from over using Chemical Sprays: RESISTANCE!
Zero Damage Concept (Where no damage was acceptable)
Failed
Resulted in Spray, spray, and spray with loss in control
Problems
Wasted money when not economic
Resulted in Resistance!!

20. Resistance
Occurs when there is an ability of a pest to tolerate a pesticide that once controlled it.
Can be managed through integrated pest management.

21. The DDT Case Study 1938; dichloro-diphenyltrichloroethane (DDT)
Extremely toxic to insects, but seemed nontoxic to humans and other mammals.
Cheap.
Broad-spectrum and persistent
Effective for disease prevention (typhus fever, malaria)
Expanded agricultural production
Paul Muller awarded Nobel prize in 1948

22. Other Problems with Dependence on Chemical Management
Increasing levels of chemical output
Chemicals persist in environment
Non-target impact
Public concern

23. Solution-Integrated Pest Management
Regulatory (Quarantines)
Cultural (Planting dates, harvest dates etc..)
Biological (Lady beetles, lacewings)
Resistance (WSS resistant winter wheat)
Gene Manipulation
Mechanical Control (Fly swatter or burning)
Chemical

24. Thank you