Thrips of hedera helix

Disease Information

Thrips (Western flower thrips and banded greenhouse thrips)

Symptoms

Infested leaves become curled or distorted with silver-gray scars or calloused areas where feeding occurred; thrips can transmit the impatiens necrotic spot virus (INSV).

Management

Control of thrips is difficult. Infested rose blossoms should be removed and destroyed. Grass and weeds in the area should be kept mowed or removed when possible. Insecticides are available but timing of sprays is very important. They must be applied before thrips enter unopened buds. In addition, because rose blooms expand rapidly, it is difficult to keep them adequately covered with insecticide. If it becomes absolutely essential to spray an insecticide, the following are available in homeowner size packaging: acephate, bifenthrin, cyfluthrin, lambda cyhalothrin, permethrin, or spinosad. Insecticidal soaps will help control thrips, but thorough coverage is necessary. The soap spray must contact the pest to be effective, and may require three sprays at 5 to 7 day intervals. Soil drenches or granular applications of dinotefuran or imidacloprid will give thrips suppression.

 



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