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Informative Updates on Ag and Natural Resources from the Far North
by Laurie Askew
on May 21, 2015 at 9:30 AM
Some fields had a problem with Blue Alfalfa aphid and no insecticide, only to see a huge build up of Lady Bird Beetles and the demise of BAA. This points out that any decision to apply insecticide should not be taken lightly and to consider the unintended consequences.  
Gene Richardson
by Steve Orloff
on May 21, 2015 at 10:01 AM
I agree with your comment that a decision to apply an insecticide(s) should not be taken lightly. That is why we have tried to emphasize that treating early may not be a wise decision, especially if the insecticide is broad spectrum and kills beneficial insects. Some of our treatments (ones that only provided partial BAA control but killed the beneficials) look far worse than the untreated control plots. However, at this point it appears some insecticides were highly effective on the BAA, yet not as disruptive to the beneficial insects. Those plots look better at this point than the untreated plots. We will harvest the plots to determine the effect on yield. Fortunately, we are seeing a high population of beneficial insects in many fields—-primarily lady bird beetles which you mentioned and syrphid flies. Syrphid fly larvae almost look like alfalfa weevil but the body shape is different (more cigar shaped and without the black head). The adults almost look like yellow jackets and the pick-up truck can get several of them inside after stopping at an alfalfa field.
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