A sticky trap is a plastic or card sheet, usually yellow or blue, coated with a non-drying adhesive. Flying insects attracted to the colour land and stick. Yellow attracts fungus gnats, shore flies, whiteflies, winged aphids, leafminers and thrips; blue is somewhat more attractive to thrips. They are first a monitoring tool and only secondarily a control.
In practice
Growers hang traps just above the canopy for flying foliar pests and close to the medium surface for fungus gnats, at a density such as one per few square metresbeing reviewed. Each week they count catches by type on a marked area, write it down and replace the card. Rising counts are the early warning. Traps also catch beneficial insects such as parasitic wasps and Orius, so they are often removed or reduced while releasing flying beneficials. Keep traps clear of buds and hair.
Don't confuse with
- Scouting: looking at plants directly; traps add a record of flying adults.
- Mass trapping: many traps to reduce numbers; rarely enough by itself.
- Pheromone trap: uses a sex attractant for specific moths.
Small dark flies of the genus Bradysia (family Sciaridae) whose larvae live in wet growing media, feeding on fungi, organic matter and young roots.Stocky dark flies of the genus Scatella (family Ephydridae) that breed in algae on wet surfaces; mostly a nuisance and contamination issue rather than a root feeder.Small white-winged sap-sucking insects of the family Aleyrodidae, mainly Trialeurodes vaporariorum and Bemisia tabaci, that fly up when disturbed and coat leaves in honeydew.Small soft-bodied sap-sucking insects of the family Aphididae that cluster on stems and leaf undersides, excrete sticky honeydew and multiply rapidly by live birth.Slender insects about 1-2 mm long, chiefly western flower thrips (Frankliniella occidentalis), that rasp leaf surfaces, leaving silvery streaks dotted with black frass.Foliar feeding is spraying a dilute nutrient solution onto leaves for quick uptake through the leaf surface; it suits micronutrient fixes but cannot replace root feeding.Using living natural enemies, such as predators, parasitoids, nematodes and microbes, to suppress pests and diseases instead of, or before, chemical sprays.Tiny parasitic wasps of the genus Aphidius that lay eggs inside aphids; the larva kills the host from inside, leaving a swollen tan mummy.Systematic, regular inspection of plants, traps and roots to detect pests and disease early, identify them correctly and record numbers for decisions.The pest or disease level, set in advance, at which a grower takes a specific control action because waiting longer would cost more than acting.
