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

Ingestion

Walking on residues or contact by spray

But note: no mention of effect on PEST

Data from research trials: avocado lace bug & lacewings in Calif.

PEST ENEMY

WANT HIGH MORTALITY WANT LOW MORTALITY

Data from research trials: avocado lace bug & lacewings in Calif.

PEST ENEMY

WANT HIGH MORTALITY WANT LOW MORTALITY

goodbad

bad

Data from research trials: whiteflies on eggplant in Egypt

(Beauveria)

parasitoids predators pest

• Helpful that 4 enemies evaluated, as well as the pest• Look for least harsh to enemies but suppression of pest

best

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 chemicalsGreen =

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 greensome 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