Short term benefits include knowing what pests survive a pesticide application. This alert the grower to the possibility of poor timing, poor application of the treatment, or pesticide resistance in the pest population. A change in the kind of treatment or pesticide can be made before the crop is significantly damaged. It is important to be able to recognize the different kinds of pests in their various stages of development. The most frequently misidentified pests in Alaska greenhouses are shore flies and fungus gnats .
Shore flies breed in algae and do little direct damage to plants.
However, shore flies are very resistant to pesticides. Fungus gnats breed in decaying roots and over watered peat moss. Fungus gnats can be very damaging to poinsettia cuttings and plants, but they can be controlled with pesticides or nematodes. Another misidentification assumes that parasitized aphids are a new kind of tan aphid which cannot be killed with insecticides. Unfortunately pesticides are often expended uselessly against shore flies and parasitized aphids.