Natural Enemies
& Insecticides
Celeste Welty
February 2012
How to use insecticides in
presence of natural enemies?
Choose product:
• Selective (by mode of action)
or
• Very short residual activity
Insecticides
• OMRI-listed, narrow spectrum
•
– viruses (Gemstar)
– bacteria (B.t.: Dipel)
– Pheromones (CheckMate-TPW)
OMRI-listed, broad spectrum
– soaps
– oils
– botanicals: neem, pyrethrins
– fungi: Beauveria
Sources of info on
non-target effects
• Scientific journals
•
– Review articles
– Individual studies
Insect supply companies
– Koppert
– Biobest
Effects of insecticides
• Direct
•
•
– Contact toxicity
– Residual toxicity
Sub-lethal effects
– Physiology
– Behavior
Indirect effects
– Food supply
4 examples of research
reports on specific systems
Data from research trials:
parasitoid of squash bug in Georgia
Walking on
residues or
contact by
spray
Ingestion
But note: no mention of effect on PEST
Data from research trials:
avocado lace bug & lacewings in Calif.
PEST
WANT HIGH MORTALITY
ENEMY
WANT LOW MORTALITY
Data from research trials:
avocado lace bug & lacewings in Calif.
good
bad
PEST
ENEMY
bad
WANT HIGH MORTALITY
WANT LOW MORTALITY
Data from research trials:
whiteflies on eggplant in Egypt
parasitoids
predators
pest
(Beauveria)
best
• Helpful that 4 enemies evaluated, as well as the pest
• Look for least harsh to enemies but suppression of pest
Koppert Biological Systems,
Webpage on ‘side effects’
for 47 natural enemies &
137 chemicals
Koppert Biological Systems,
Webpage on ‘side effects’
for 47 natural enemies &
137 chemicals
Green =
good
Red=
bad
Koppert: lacewings & spinosad
Koppert: lacewings & spinosad
Note difference between life stages
Next 3 slides…
use Koppert charts to compare
multiple enemies & multiple chemicals
look for general trends:
some columns mostly green
some columns mostly red
Koppert: 4 predator insects & 7 OMRI products
Koppert: 4 parasitoid insects & 7 OMRI products
Koppert: 3 predatory mites & 7 OMRI products
Biobest:
Webpage & new mobile app on ‘side effects’
for 21 natural enemies & 263 chemicals
Biobest: 4 predators & 5 OMRI products
Note similar trends as on the Koppert charts
Trends?
• Not harsh:
•
•
– azadirachtin
– B.T.
Harsh:
– soap (potassium salts of fatty acids)
Mixed results:
– spinosad
– pyrethrins
– mineral oil
Caution…
• These do not include
consideration of efficacy of
chemical against the PEST….
Hierarchy of harshness to
natural enemies
Spray conventional (non-OMRI) >>
Spray OMRI broad spectrum (soaps,
oils, botanicals, fungi) >>
Spray OMRI narrow spectrum
(viruses, pheromones, bacteria) >>
No spray