"Will Henderson, Clemson University graduate
student, takes an air sample from an undamaged cotton plant to get a baseline reading which can be compared later to field-grown plants that may be damaged by stink bugs."

DATE: 5/23/05

CONTACT: Dr. Ahmad Khalilian, (803) 284-3343, ext. 230

WRITER: Tom Lollis, (803) 284-3343, ext. 241

If Cyranose knows, stink bug diagnosis could be a lot easier

BLACKVILLE – In the science fiction world of Star Trek, a farmer can diagnose insect problems in his crops just by whipping out a device called a Tricorder, outfitted with sensors to detect all kinds of life signs.

Scientists at Clemson University ’s Edisto Research and Education Center are working with a real-world version of a hand-held sensor that farmers may one day use to detect stink bug problems in cotton.

“It’s called the Cyranose 320,” said agricultural engineer Ahmad Khalilian. “It’s like an electronic nose, and it’s used in places like airports to sniff out drugs and explosives.”

When activated, the sniffer sucks in a small amount of air, routing it over a 32-sensor chip, where a chemical’s signature is imprinted. In this case, Clemson scientists are interested in the chemicals given off by a cotton plant when bolls have been damaged by stink bugs.

“Over millions of years cotton has evolved to the point that it can make a chemical cry for help to predator insects when it is attacked by a pest such as the stink bug,” said Sam Turnipseed, Clemson research entomologist at Edisto REC. “The chemical that is released is specific to the type of insect attacking the plant.”

For example, a parasite of budworms – Cardiochiles nigriceps – will go to cotton plants infested by budworms, but not bollworms, a closely related lepidoptera.

Will Henderson, a master’s student at Clemson, is working with Khalilian to collect data on the volatiles given off by cotton plants so they can compare volatiles from damaged plants to the volatiles from undamaged plants. They will also be “sniffing” the chemicals given off by the stink bug to see if Cyranose can be programmed to detect the pest directly.

“If this works, we hope to be able to develop a hand-held device that a farmer or scout can take to the field and measure the amount of stink bug infestation so decisions on pesticide applications can be made,” said Khalilian.

Under current scouting practices, a farmer or scout has to pull several bolls at random in the field then cut open each boll to assess damage.

“It’s a system that is so laborious and time consuming, that it is seldom done correctly,” said Turnipseed. “Growers usually spray an entire field when they find a few stink bugs, a few damaged bolls or when a field has a history of stink bug infestation,” A grower spends an average of $7 an acre for chemicals, equipment and labor every time he sprays for stink bugs.

“A sniffer would make it possible just to spray the hot spots, and save a lot of money over a season,” he said.

“We also need to find a way to bring the price of the sensor down to a couple of hundred dollars or less,” said Khalilian. The Cyranose 320 costs $5,500. Eventually he also hopes to be able to develop a sensor that could be mounted on spray equipment and be programmed to decide whether to spray insecticide, based on what is sniffed out in the field.

Turnipseed said that stink bugs have become more important as a pest in cotton since the introduction of transgenic cotton varieties which control bollworms and budworms.

“Stink bugs used to be coincidentally controlled by the insecticides we used to control bollworms and budworms in older, traditional cotton varieties,” he said. From 1995 to 2001, insecticide applications for stink bug control increased across the cotton producing states from zero to four million at a cost of $27 million. In 2000, crop losses from stink bugs exceeded $50 million.

Support for the project is coming from Cotton Incorporated, the S.C. Cotton Board, the Environmental Protection Agency and the Southern Region IPM Committee of USDA. Ag engineers Young Han and Roy Dodd and entomologist Mike Sullivan are also part of the team.

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