December 12, 2007

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When chilli thrips damage rose buds, the resulting flower — if it develops at all — is discolored and misshapen.


A solitary specimen of chilli thrips makes its way along the central vein of a rose leaf. Though they are only about 2 mm — little more than one-sixteenth inch — long, chilli thrips can cause substantial damage. The blotchy discoloration of the leaf is evidence of feeding by chilli thrips. (Texas Cooperative Extension photos by Dr. Scott Ludwig)

  Chilli thrips invade Texas landscapes, gardens

By Robert Burns
Texas Cooperative Extension

Home gardeners throughout the southern U.S. need to be on the lookout for a new pest that attacks many popular landscape plants, say Texas Cooperative Extension experts.

The pest is called chilli thrips, which is a somewhat misleading name as the insect feeds on many plants other than just peppers, said Dr. Scott Ludwig, Extension entomologist and integrated pest management specialist.

"It's not going to go through the landscape and eat everything, but it is known to attack plants in 40 plant families, including many foundation plants in the landscape," said Ludwig, who is a member of a national chilli thrips task force.

Susceptible landscape plants include roses, ligustrum, lisianthus, pittosporum, herbs including sweet basil, begonia, and Indian hawthorn.

"There are others, but in Florida, where the pest was discovered two years ago, these are plants where it is commonly observed," Ludwig said.

The pest significantly changed how Florida landscape companies provided pest-control services, Ludwig said. "Though the pest is easily killed with certain insecticides, we have not found any insecticides that provide long-term preventive control," he said. "The landscape companies found themselves spraying every two or three weeks — whenever the plants had a new flush of growth." The pest is mainly a forage feeder, preferring new leaves and buds. Unlike aphids, another common plant pest, chilli thrips do not use a proboscis to puncture a plant and suck out juices. Instead, they use a "rasping" motion to wear away the outer tissue of leaves and buds, Ludwig said. Then the thrips suck sap from the wound. This feeding action causes a distinctive brownish-bronze discoloration in leaves and buds.

The damage is often more than just unsightly. Damaged rose buds, for example, will yield misshapen flowers or fail to bloom.

The pest is not just a risk to home gardens and landscapes, Ludwig said. It poses a substantial risk to cotton, peanuts, grapes, tomatoes and hot peppers. The introduction of the pest in Texas has been traced to garden centers that import plants from out of state. For this reason, it is most likely to become a problem in ornamental landscapes. The pest was recently found on landscape roses in Houston.

It's no surprise chilli thrips were detected in roses first, Ludwig said. Roses are a very popular landscape plant in Texas. Growers of the older, traditional rose lines will probably not have to worry though, he said. This is because the older varieties require frequent spraying, and the same controls used for other insect pests on roses will control thrips too.

However, newer varieties of roses that do not require frequent spraying may be damaged by chilli thrips, he said.

And Ludwig doesn't recommend preventive spraying. "What you'll most likely do is kill beneficial insects: the same ones that offer some control of thrips and other pests," he said.

The pest is about 2 millimeters or little more than one-sixteenth inch long and hard to identify by anyone except a professional entomologist. Instead, it's better to carefully monitor plants for signs of damage the pest causes, Ludwig said.

Extension and the national task force to which Ludwig belongs are trying to develop control recommendations — particularly long-term controls — for the pest, he said. Because thrips, like any other insect, will adapt to different environments quickly, Extension entomologists need to track the spread of the pest through Texas.

Home gardeners who think they may have an infestation may get help one of two ways, Ludwig said. One way is to contact the Extension office in their county. Contact information can be found on the Internet at http://county tx.tamu.edu/. Or they may visit a Web site that Ludwig maintains at http://chillithrips.tamu.edu.

The Web site has contact information as well as pictures to help identify chilli thrips damage and ways to control the pest.

Ludwig emphasized that home gardeners shouldn’t start spraying just because they suspect they have chilli thrips.

"More often than not, indiscriminate spraying does more damage than good," he said. "Not only will they waste money and risk damaging their plants, they may kill the very beneficial insects that naturally help keep thrips in check.

"There are many things that mimic thrips feeding damage, including herbicide damage, some diseases and broad mites."


  South Texas sago palm pest headed north

By Rod Santa Ana and Paul Schattenberg
Texas Cooperative Extension

A pest known to be a threat to landscape plants in South Texas appears to be making an unwanted appearance farther north, according to Texas Cooperative Extension experts.

"We’ve learned that there are instances of cycad aulacaspis scale infestation in and around the Bexar County area," said Molly Keck, Extension entomologist and integrated pest management specialist for the county. "This can cause serious damage to sago palms, which are very popular landscape plants in the area."

The sago palm is not actually a palm but a cycad, said David Rodriguez, Extension horticulturist for Bexar County.

"Sagos have become a very popular landscape plant in South and Central Texas due to their palm-like appearance and generally hearty and slow-growing nature," he said. "They typically don’t have many insect problems, but the aulacaspis scale pest can do serious damage. And if left untreated, it can kill the plant."

Cycad aulacaspis scale is also known as Asian cycad scale and sago palm scale. The pest originated in Thailand and was introduced into the U.S. in Florida in the 1990s.

The pest was reported in the Rio Grande Valley in 2004, said Boris Castro, Extension entomologist with the Texas A&M University System Agricultural Research and Extension Center at Weslaco. In 2006, it reached outbreak levels there.

“Currently this scale continues to cause tremendous economic losses here in the Rio Grande Valley,” Castro said. “The landscape industry has lost millions of dollars in sales and in expenses to control this pest. And while infestations don’t appear to be as heavy this year, the damage is more visible now, especially in sago palms growing in the lower Valley, nearer the coastal area.”

The tiny, white, flat, scale-like pest damages sago palms by sucking the juices out of their leaves, also called fronds, Keck said.

"One of the initial indicators of a possible infestation by this pest is yellow spots on the leaves," she said. "The insect can reproduce quickly and prolifically, so the infestation can spread rapidly and possibly kill a plant within a month."

The insect has a waxy exterior that resists penetration, making it difficult to control through many insecticides, she said.

"It also has no known natural enemy to help keep its spread in check," she said.

Castro, one of the authors of the Extension publication "Pest Management Suggestions for Cycad Aulacaspis Scale in Landscapes," added there are several effective cultural and chemical controls for the pest.

Education and vigilance are key to reducing plant damage, he said.

“Stay informed about the latest information about this very destructive pest and keep an eye out for early infestations,” he said. “They are much easier and cheaper to treat when infestations are still low. Once infestations become severe, your options are reduced to either heavy pruning or total destruction of the plant.”

For homeowners, pressure-wash spraying both sides of the plant fronds is an effective means of dislodging the scales, he said, as is the regular application of an insecticide labeled for use against the pest.

There are several low-cost insecticides available at garden centers for controlling scale insects, Castro said. Homeowners can manage the pest by using horticultural spray oils or insecticidal soaps.

Castro also suggested pruning any infested fronds and disposing of the cuttings in a double-sealed plastic bag to prevent reinfestation.

Keck noted the only reports of cycad aulacaspis scale in Bexar County to date have been of sago palms already planted for landscape use.

"There’s been nothing reported about a possible infestation in a sago palm at a nursery, commercial greenhouse or other commercial landscaping business," she said.

Although "green" industry businesses generally do a good job of identifying and managing pests, Rodriguez suggests carefully inspecting the fronds of any sago palm intended for home or commercial landscape use.

"Look for tell-tale signs such as the typical yellow spots and give it a close look to see if you can find any clusters of small, scale-like shapes, which are predominantly found on the underside of the fronds" he said. "If you find them, inform the nursery manager and the Texas Department of Agriculture. And if you have a plant you suspect has the scale, you can bring a sample to your local Extension office for evaluation.”

Homeowners should also inspect their sagos on a regular basis to determine if any scales are present, he added.

While there don’t appear to be too many instances in Bexar County where the pest has been spotted, it is important to know that the wind can spread the pest or it can "hitch a ride" on gardening tools, as well as spreading through more direct means of contact and infestation, Keck added.

Extension continues to work with other agencies and organizations to monitor the scale situation and develop long-term solutions to controlling this pest, noted Castro.

Free information on management of cycad aulacaspis scale can be found at http://insects.tamu.edu/extension/publications/epubs/CAS_control_tips-landscape4.pdf.


  Gardening tips

"After tilling your vegetable garden in the spring, lay boards across the surface for walking," writes Barry Goldman. "That way you can avoid compacting your freshly prepared soil. In a flower bed, use strategically placed rocks to accomplish the same purpose."

Have a favorite gardening tip you'd like to share? Texas Gardener's Seeds is seeking brief gardening tips from Texas gardeners to use in future issues. If we publish your tip in Seeds, we will seed you a free Texas Gardener T-shirt. Here's a chance to get published and be a garden stylist as well! Please send your tips of 50 words or less to the editor at: Gardening Tips.


  Did you know...

Cirrus clouds are delicate clouds with ragged edges that appear very high in the sky. Watch for rain or snow within 24 hours of cirrus clouds showing up and thickening, then giving way to lower clouds.


 

  Upcoming garden events

Galveston: Festive sights and sounds will fill Moody Gardens at the sixth annual Festival of Lights November 17 through January 5. This whimsical celebration will kick off the holiday season on November 17, with Santa Claus parachuting in to switch on the lights. Festival of Lights is celebrated Thursday through Sunday November 17 through December 16, and daily beginning December 17. Transforming its lush tropical garden setting into a winter wonderland, Moody Gardens will be adorned with more than a million twinkling lights and dozens of light displays. In addition to experiencing the lights, guests can also strap on a pair of skates and glide across the ice at the Outdoor Ice Rink at Moody Gardens. Indoors, visitors can take pictures with Santa or even gaze upon a giant poinsettia tree. Moody Gardens will feature a variety of holiday-themed films during the Festival of Lights. Three films will be playing at the IMAX 3D theater and two films will be playing at the Ridefilm theater. The Garden Restaurant will feature a delectable holiday buffet, offered from 4 p.m. to 9 p.m. Group rates of $20 per person are also available for groups of 20 or more, and include admission to Festival of Lights and the holiday buffet. Admission into the Festival of Lights is $5.95, and tickets to additional attractions including the Rainforest Pyramid, holiday IMAX 3D film, holiday Ridefilm, Outdoor Ice Rink and Colonel Paddlewheel Boat, can be purchased for only $4.00 each. For more information, call Moody Gardens at (800) 582-4673 or visit www.moodygardens.org.

Lake Jackson: For several years John Panzarella has hosted a citrus tasting and open house in his backyard, 404 Forest Drive, Lake Jackson, which is about 50 miles south of Houston. The next open house will be Saturday, December 15 from 2 p.m. until 4 p.m. Taste 40 to 50 citrus varieties and see different varieties of fruit trees. Panzarella has approximately 200 different varieties of citrus, 50% to 70% fruiting, plus several varieties of persimmon, sapote, guava, pawpaw, loquat, pomegranate, avocado, papaya, fig, peach, passion fruit, mango and pecan trees growing in his backyard. You are invited to visit, taste the citrus, and see one of the largest citrus collections in the state of Texas and the largest collection north of the Texas Rio Grand valley. See the giant Panzarella orange and the giant 10 lb. Panzarella cluster lemons. You will also have the opportunity to view a multi-grafted tree which has grapefruits, tangerines and oranges growing on it. For more information, call (979) 297-2120, e-mail jpanza@swbell.net, or visit http://johnpanza.googlepages.com.

Houston: Urban Harvest Fruit Tree Sale will be held Saturday, January 19, from 9 a.m. until 1 p.m. A class describing all varieties for sale, as well as providing vital information on how to plant and care for each type tree will be held January 5 and 12 (your choice), from 2 to 4 p.m. A nominal fee of $10 is charged for the class. Register for the class by calling Urban Harvest. Sale and classes at Emerson Unitarian Church, 1900 Bering Dr., Houston. For detailed information about the sale as well as about fruit trees, check the Urban Harvest website www.urbanharvest.org.

Tomball: The annual Fruit Tree Sale and Seminar presented by Heidi of Treesearch Farms will be held at The Arbor Gate, 15635 FM2920, Tomball, on Saturday, January 27. The day begins with a free seminar at 9 a.m. The sale begins at 10:30 a.m. For additional information, contact (281) 351-8851 or visit http://www.arborgate.com.

Tyler: The 15th annual East Texas Spring Landscape & Garden Conference will be held February 16, from 8:30 a.m. until 3:30 p.m. at the Tyler Rose Garden Center, 420 Rose Park Drive, Tyler. Featured speakers include Dr. Jerry Parsons, Joe Novak, Aubrey King, and Tim Lanthrum. Topics include "Texas Superstars in Your Garden," "Secrets of Successful Vegetable Gardening," "Gardening for a Lifetime," "Landscaping with Texas Native Plants," "Common Problems with Small Engines and How to Prevent Then," and "Calibrating Sprayers and Spreaders." Cost: $15, which includes lunch. For additional information, contact Keith Hansen at (903) 590-2980 or khansen@ag.tamu.edu, or visit http://EastTexasGardening.tamu.edu.

Houston: River Oaks Garden Club will host its 73rd annual Azalea Trail Friday through Sunday, March 7, 8 and 9 from 11 a.m. until 6 p.m. each day. Azalea Trail, 2008, will celebrate the 51st anniversary of Miss Ima Hogg's gift of her beautiful home and gardens, Bayou Bend, to the Museum of Fine Arts, Houston. The trail will feature four private houses and gardens, as well as Bayou Bend, Rienzi and the River Oaks Garden Club Forum of Civics Building and Gardens. Tickets for seven admissions are $15 before March 7 and $20 during the trail. Single admissions are $5. For additional information, call (713) 523-2483 or visit http://www.riveroaksgardenclub.org.

Tomball: The Arbor Gate will host its third annual Rose Festival March 8. More than 100 varieties of old and antique roses will be available, as will guest speakers and informative booths. The Arbor Gate is located at 15635 FM2920, Tomball. For additional information, contact (281) 351-8851 or visit http://www.arborgate.com.

Burnet: The Highland Lakes Master Gardener Association will sponsor the 10th Annual Hill Country Lawn and Garden Show, March 22, from 9:30 a.m. until 4 p.m. at the Burnet Community Center on E. Jackson in downtown Burnet. The show features garden-related vendors, a children's booth, a raffle, and seminars. Admission is free. For more information, visit http://hillcountrylgshow.com or call Paula Montandon, Show Chairman, at (830) 693-0163.

Galveston: Moody Gardens and the International Oleander Society will host the Earth Day and Oleander Festival at Moody Gardens on Galveston Island April 26-27. The Oleander Festival is an annual event dating back to 1921 that honors the beautiful flower and educates guests about the history of the oleander on Galveston Island and throughout the world. Area plant societies, clubs, and vendors are invited to set up booth space to display and sell their plants. There will be a floral design competition were professional, amateur and child participants can display their work to be judged. Earth Day celebration activities by Moody Gardens and its community partners will include arts and crafts, entertainment and presentations great for the whole family. "We are pleased to bring these two events together here at Moody Gardens in Galveston," said John Zendt, General Manager of Moody Gardens. "We are excited about promoting the environmental conservation missions of both Moody Gardens and the International Oleander Society and inviting the public to have some fun while learning about global and local environmental issues." Admission to the Earth Day and Oleander Festival is free to the public. For more information, call Moody Gardens at (800) 582-4673 or visit www.oleander.org.

Kilgore: Northeast Texas Organic Gardeners meets at 1 p.m. on the first Wednesday of each month at a new eco-farm in Kilgore. If there is enough interest, we will also start a Sunday afternoon monthly meeting. For more information, call Carole Ramke at (903) 986-9475.

League City: The Kemah-Bay Area Garden Club meets the first Wednesday of each month at the Amegy Bank, 303 East Main Street, League City. For additional information, contact Nancy Busko, president, at (281) 332-5294.

Allen: The Allen Garden Club meets on the first Thursday of each month at 7:30 p.m. at the little blue-gray house located at 102 N. Allen Dr., Allen. For more information, visit www.allengardenclub.org.

Austin: Austin Organic Gardeners meet at 7 p.m. on the second Monday of each month at the Zilker Botanical Gardens in Austin. For more information, visit www.main.org/aog.

Rockport: The Rockport Herb & Rose Study Group, founded in March 2003, meets the second Wednesday of each month, with the exceptions of June and July, to discuss all aspects of using and growing herbs, including historical uses and tips for successful propagation and cultivation, meets at 619 N. Live Oak Street, Room 14, Rockport at 10 a.m. Sometimes they take field trips and have cooking demonstrations in different locations. For more information, contact Linda (361) 729-6037, Ruth (361) 729-8923 or Cindy (979) 562-2153 or visit www.rockportherbs.com.

San Antonio: The San Antonio Herb Society meets at 7 p.m. on the second Thursday of each month at the San Antonio Garden Center, 3310 N. New Braunfels (corner of Funston & N. New Braunfels). For more information on programs, visit www.sanantonioherbs.org.

Dallas: The Rainbow Garden Club of North Texas meets the second Sunday of each month at 2 p.m. Everyone is welcome. Meetings are held at member's homes and garden centers around the area. For more information, visit www.RainbowGardenClub.com.

Denton: The Denton Organic Society, a group devoted to sharing information and educating the public regarding organic principles, meets the third Wednesday of each month (except July, August and December) at the Denton Senior Center, 509 N. Bell Avenue. Meetings are free and open to the public. Meetings begin at 7:00 p.m. and are preceded by a social at 6:30. For more information, call (940) 382-8551.

Seguin: The Guadalupe County Master Gardeners meets the third Thursday of each month at the Texas Cooperative Extension Bldg. at 210 E. Live Oak at 7 p.m.  For more information, phone (830) 379-1972 or visit www.guadalupecountymastergardeners.org.

Fort Worth: The Organic Garden Club of Forth Worth meets at 7 p.m. on the fourth Tuesday of each month except July and December at the Fort Worth Botanic Gardens main building. Refreshments are served. For more information, call (817) 274-8460.

Dallas: The Dallas Organic Garden Club meets at 6:45 p.m. on the fourth Thursday of each month at the Fretz Park Recreation Center, located at the corner of Hillcrest and Beltline Road in Dallas. For more information, call (214) 824-2448 or visit www.dogc.org.

Arlington: The Arlington Organic Garden Club meets from 7 p.m. until 9 p.m. on the last Thursday of each month (except November and December) at the Bob Duncan Center, 2800 S. Center Street, Arlington. For more information, contact David at (817) 483-7746.

If you would like your organization's events included in "Upcoming Garden Events," please contact us at Garden Events.


  Doug Welsh's Texas Garden Almanac

Doug Welsh's Texas Garden Almanac is a giant monthly calendar for the entire state — a practical, information-packed, month-by-month guide for gardeners and "yardeners." This book provides everything you need to know about flowers and garden design; trees, shrubs, and vines; lawns; vegetable, herb, and fruit gardening; and soil, mulch, water, pests, and plant care. It will help you to create beautiful, productive, healthy gardens and have fun doing it.

$26.63 plus shipping*

Order by calling 1-800-727-9020 or order on-line.

*Mention Texas Gardener's Seeds when ordering by phone during the month of December and we'll waive shipping charges. (Discover, MasterCard and Visa accepted.)


  Fiber row cover valuable year-round

Grow-Web encourages plant growth and development, and also provides protection from insects, birds, diseases and frosts. It is also air and water permeable and allows for ventilation. Grow-Web provides excellent protection to seedlings when applied directly to the seedbed.

 $30.64 per 12.3' x 32.8' roll (includes shipping!)

Order by calling 1-800-727-9020. Not available through on-line bookstore.

(Discover, MasterCard and Visa accepted.)


 


Texas Gardener's Seeds
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