[ Home ]

Chili Thrips

One pest that DPI is currently watching for is the chili thrips, which could pose a significant threat to Florida agriculture.

Scirtothrips dorsalis is a significant pest of chili pepper, citrus, onion and many other crops in tropical and subtropical regions of Asia, Africa, Eastern Europe, and Oceania. Recently S. dorsalis was confirmed for the first time from the Caribbean island of St. Vincent.  In different parts of the world, the insect is known as castor thrips, chili thrips, berry thrips, Assam thrips or yellow tea thrips. 

The global distribution of this species suggests that approximately 28% of the continental US would have a suitable climate for S. dorsalis.

This pest feeds on a variety of wild and cultivated plants including many fruits and vegetables include peppers, tomato, strawberry, mango, grape and many other important crops grown in Florida.  Scirtothrips dorsalis feeds on new growth of nearly all parts of host plants including buds, leaves, flowers, fruits and stems.  Feeding deforms young leaves and stains or scars fruits. 

Since thrips are difficult to distinguish from one another, especially when immature, this species may be easily overlooked when first introduced into an area.  Interceptions of S. dorsalis or “Scirtothrips sp.” have been reported 89 times since 1984, primarily on cut flowers and fruits.  The most commonly reported destinations were California (36%), Texas (14%), Illinois (10%), Georgia (8%), Florida (8%), New York (4%), and Massachusetts (4%). With the exception of California, some portion of each of these states has a climate and hosts that would be suitable for establishment by S. dorsalis.

In addition to interceptions at ports of entry, Scirtothrips has been detected at least twice by PPQ officers at inland locations in Florida.

Since polyphagous thrips rarely occur as a single species on a plant host, it is difficult to estimate the economic impact of S. dorsalis alone. Feeding on the surface of young plant tissues creates wounds, which initially appear shiny and silver and become yellow to greenish-brown. Flowers become brown and wilted in appearance. Under dry weather conditions, population densities tend to increase, and heavier feeding damage results. Symptoms of feeding are also more pronounced and appear more quickly when plants are water stressed.

Scirtothrips dorsalis is a pest of economic importance in citrus growing regions of Asia, where feeding by piercing, sucking mouthparts can cause significant leaf and flower deformation, fruit damage, and yield reduction.  Scirtothrips dorsalis is also an economically important pest of chili pepper; where feeding can wilt, distort, or stunt young leaves/shoots and cause premature leaf, bud or flower drop. In some varieties of chili peppers, 75% of leaves may be deformed due to the activity of piercing-sucking insects.  Yield losses attributed to S. dorsalis in chili pepper range from 20% to nearly 50%.  The insect is also a key vector of tomato spotted wilt virus.

Given the fact Scirtothrips dorsalis has been detected in or near areas of the US with suitable hosts and climate, establishment potential is believed to be high.

 If you see unusual outbreaks of thrips, agents should contact IFAS specialists for assistance with identification and/or notify DPI.

(Gene McAvoy, Hendry County)