THRIPS

Thrips are very small insects in the order Thysanoptera which are only slightly larger than spider mites, and hard to see with the naked eye. They are elongated and typically a tan or yellowish color although some species are darker brown or black. Thrips feed by scraping the outside of the leaves off and cause irregular silvery spots. They also damage young leaves as they are forming causing them to be distorted as they grow. They cause similar damage to flowers, infesting flower buds and damaging petals or even causing the flower to abort. In addition to damage from feeding they are also disease carriers and one of the most common vectors for many plant viruses.

Some strains of thrips have developed resistance to many pesticides while others are still more easily treatable. Thrips can be annoying to eradicate because they can lay eggs inside of plant parts and some stages of the lifecycle are spent in the soil. Typically it will require several treatments to eradicate them all.

Non pesticide options (not recommended):

• Horticultural oil / dormant oil - This is a mechanical pesticide. It kills thrips by suffocating them and is only active on the exposed stages. It does not kill eggs and cannot be used to treat soil borne stages. It requires direct contact and has no residual action. Horticultural oil and other oil-based pesticides can damage leaves. They can cause burning or other damage to leaves if applied when temperatures are high (80-85F or higher) or if the leaves are sensitive. Always test it on a couple leaves first before spraying a whole plant

• Soapy water & peroxide - Real soap like Dr. Bronner’s or safer insecticidal soap + 3-4 TBSP of 3% hydrogen peroxide per cup of water. Spray on and then use a soft, damp cloth to physically wipe the thrips off the leaves. Rinse with plain water. Direct contact only, no residual effect

• Sticky traps – These will provide early warning of thrips but don’t do anything to control or suppress them