Chilli Thrips E-Learning Module Released!

The National Plant Diagnostic Network is pleased to announce the release of the chilli thrips e-learning module. Chilli thrips, Scirtothrips dorsalis, has been an emerging pest issue in Florida and other southern U.S. states since 2005. This new invasive pest has an extremely wide host range, attacking more than 40 plant families. Chilli thrips has been particularly problematic on ornamental plants, but agronomic crops, such as peppers, blueberries, strawberries, cotton and peanuts are also at risk.

The chilli thrips e-learning module will provide learners with an introduction to the distribution, life history, and pest status potential for chilli thrips, in the U.S.

Upon completing this module you will:
• Be familiar with the origin and current status of chilli thrips in the U.S.
• Be familiar with damage symptoms.
• Understand the life cycle of chilli thrips.
• Know general management options.
• Be familiar with local resources for obtaining management recommendations.
• Understand thrips sampling techniques.
• Know how to submit a thrips sample to an appropriate diagnostic laboratory.

In order to view the chilli thrips e-learning module, go to http://cbc.at.ufl.edu/ and click on ‘take the online modules’. If you do not have an account set up with the National Plant Diagnostic Network, you will need to do so in order to view this module along with others on the site. The website contains simple instructions for creating your account.

The chilli thrips e-learning module includes a post-test. As of March 2010, a ‘certificate of completion’ for the chilli thrips module will be available for download once the module has been completed at the 70% level or higher.

Please direct questions regarding the NPDN e-learning program to Amanda Hodges achodges@ufl.edu.

The chilli thrips training module was developed by Amanda Hodges, Lance Osborne, Howard Beck (University of Florida/IFAS), and Scott Ludwig (Texas AgriLife Extension Service)

Chilli Thrips Invade East Texas

Earlier this month I received plants from an East Texas wholesale nursery with damage that the grower thought was possibly herbicide damage. As soon as I put the sample under the microscope my worst fears came true. The damage was not the results of a preemergent herbicide. Rather, the damage was from chilli thrips. I went out to the nursery and walked the entire facility with the grower to determine what plants were impacted. We estimated that approximately 20% of the nursery was infested with chilli thrips. The good news is that we have the tools to develop a management program that should be able to clean up the nursery. Unfortunately, we were unable to determine where the thrips came from. I would suggest that all ornamental crop producers and landscapers in the state be on the lookout for unusual plant damage.

Description. Chilli thrips are extremely small and difficult to distinguish from other thrips species without the aid of a good hand lens or compound microscope. Adults are pale with dark wings and less than 1 mm in length. Immature chilli thrips are also pale in color and resemble the immature stages of many other thrips species.

Feeding Damage. Chilli thrips infestations are usually first detected by their distinctive feeding damage. Unlike flower thrips, which feed primarily on pollen, chilli thrips feed on various plant tissues. Feeding causes bronzing (tissues turning bronze in color) of leaves, buds, and fruit. Damaged leaves may curl upward and appear distorted. Infested plants become stunted or dwarfed and leaves may detach from the stem at the petioles in some plant species. Feeding may also cause buds to become brittle and drop. Young leaves, buds and fruits are preferred, although all above-ground parts of host plants may be attacked. Damage can be easily confused with herbicide damage, broad mites, or even a foliar pathogen.

Chilli thrips damage on pomegranate

Chilli thrips damage on Japanese maple

Host range. Chilli thrips have a very broad host range and may feed on many of the common plants. All broadleafed plants should be considered potential hosts for this thrips. Some of the more common plants attacked are roses (all types), Indian hawthorn, cleyera, begonias, plumbago, blueberry, schefllera, duranta, sweet viburnum, verbena, oaks, live oak, red maple, Japanese maple, grape, Japanese maple, English ivy, viburnum, and ornamental peppers.

Chilli thrips damage on shrub roses

Chilli thrips damage on Indian hawthorn

Plant Monitoring and Identification. Plants with the symptoms described above should be examined closely for the presence of thrips. Thrips collected from the leaves or buds of plants with suspected damage should be collected and properly identified. If you wish to participate in efforts to monitor the distribution of this pest in Texas, place samples of thrips or suspected thrips-infested plant parts into a Ziploc bag, add a dry piece of paper towel or napkin to avoid excessive moisture, and seal the bag. Label the bag with collection information including locality (city or town and county), date, species of host plant, and your name and contact information. Send samples via express mail (next-day delivery) to assure good sample quality. Please send samples to: Chilli Thrips Lab, Texas AgriLife Extension Service, P.O. Box 38, Overton, TX 75684

Chilli Thrips and Pink Hibiscus Mealybugs Invade Houston

Two insect pest species that made news last year because of their first appearance in Texas are causing serious problems for homeowners and landscapers in the Houston area. While these pests are currently in the landscape, they have the potential to move into production greenhouses and nurseries.

Populations of the pink hibiscus mealybug were recently confirmed in Brazoria, Galveston and Harris counties, triggering TV-news coverage and subsequent reports from homeowners in a number of areas in Houston. The Texas Department of Agriculture, after confirming the pink hibiscus mealybug infestations, have initiated surveys of surrounding areas and will be making releases of natural enemies. Biological control has provided excellent control in Florida and will likely be the long term solution in Texas. Using reduced risks insecticides such as insecticidal soaps and oils, in combination with good sanitation practices should help homeowners minimize plant losses and facilitate establishment of released natural enemies.

A large population of chilli thrips was also detected recently in Houston. A survey was conducted of the entire Medical Center complex and chilli thrips or signs of chilli thrips were found at every rose bed. Chilli thrips were also found on other roses outside the Medical Center. The actual distribution of the infestation is currently unknown.

It is important to remember that chilli thrips attack more than just roses. They can attack a wide range of landscape plants, horticulture crops and row crops.

For the most up to date information on chilli thrips in Texas visit http://chillithrips.tamu.edu/. I will be updating the site this weekend. New information should be posted by August 5th.

Texas Chilli Thrips Update

There has been a lot of questions and concerns regarding chilli thrips over the last year. I thought this would be a good time to provide an update. The good news is that we have only been able to confirm one infestation in Texas. Last fall a homeowner in Houston submitted a sample from plants in her yard that were being damage. It turned out that the damage was caused by chilli thrips. The unusual damage caused by this thrips to the plant's foliage is the easiest methods to detect this pest (see photo).

There are no indications that any greenhouse or nursery producers in Texas are infested. One of the most important ways of keeping your facility clean is to properly inspect all incoming plant material.

If there is any good news about this pest, it is that at this time there appears to be a number of insecticides that will kill it. Almost any insecticide that is label for thrips control will kill chilli thrips. Abamectin, chlorfenapyr, pyridalyl, spinosad and systemic insecticides (acephate, acetamiprid, clothianadin, dinotefuran, imidacloprid, thiamethoxam) applied as a foliar sprays have been shown to be effective in efficacy testing.

For more information on chilli thrips in Texas visit http://chillithrips.tamu.edu/.