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>> THE THOUSANDS OF ACRES OF
CROPS THAT GROW AROUND UVALDE,
TEXAS ARE AN ATTRACTIVE SIGHT
TO A HUNGRY WORLD.
THEY'RE ATTRACTIVE TO INSECTS.
THAT MAKES THEM
ATTRACTIVE TO BATS.
AND THAT MAKES THEM
IRRESISTIBLE TO THREE
RESEARCHERS WHO ARE TRYING TO
DEVELOP A WHOLE NEW APPROACH
TO PEST CONTROL.
UVALDE IS NOT YOUR
TYPICAL TEXAS TOWN.
>> UVALDE SETS AT THE
INTERSECTION OF TWO OF THE
LONGEST HIGHWAYS IN THE
UNITED STATES.
(music)
WE CALL IT A RURAL COMMUNITY.
AND IT'S AN AGRICULTURAL
COMMUNITY.
OUR ENTIRE ECONOMY IS
BASED ON AGRICULTURE.
(music)
WE CAN RAISE A VEGETABLE
CROP ALMOST 12 MONTHS
OUT OF THE YEAR.
WE HAVE VERY, VERY MILD
WINTERS AND THE CROPS CAN
STAND THE COLD TEMPERATURES
THAT WE HAVE.
AND SO ANY GIVEN MONTH THERE
IS SOME VEGETABLE CROP IN THE
GROUND OR BEING HARVESTED.
83 MILLION DOLLARS, AG
INCOME, HISTORICALLY IS WHAT
WE NORMALLY RUN AND SO
AGRICULTURE IS BIG BUSINESS
AND IT IS THE MAIN BUSINESS
IN THE REGION.
>> BUT THE FERTILE FIELDS OF
UVALDE FACE MANY ENEMIES.
(music)
>> ONE OF THE WORST IS THIS ONE.
THIS IS THE DREADED,
CORN EARWORM MOTH.
THIS MOTH FLIES INTO
CORNFIELDS IN SEARCH OF
PLANTS WHERE THEY CAN
DEPOSIT THEIR EGGS.
IT DOES THIS WHEN THE
YOUNG EARS ARE SILKING.
THE EGGS HATCH INTO HUNGRY,
DESTRUCTIVE LARVAE THAT FEED
RELENTLESSLY ON THE SUCCULENT
SILK AND TENDER KERNELS.
THE LARVAE ARE AGGRESSIVE
AND WILL KILL OTHER LARVAE
THAT TRESPASS ON THEIR
EAR OF CORN.
AFTER ABOUT TWO WEEKS OF
GORGING ON THE CORN, THE
BLOATED LARVAE DROP TO THE
GROUND AND BURROW
INTO THE SOIL.
THIS SUBTERRANEAN LAIR IS
WHERE THEY PUPATE AND COMPLETE
THEIR TRANSFORMATION
INTO MOTHS.
AFTER TWO WEEKS UNDERGROUND,
THE PUPA HATCHES INTO A MOTH.
IT FIGHTS ITS WAY BACK
TO THE SURFACE.
THE NEWLY EMERGED MOTH
CAN'T FLY JUST YET.
THEIR WINGS MUST FIRST
UNFOLD AND EXTEND.
NOW THEY ARE READY TO INVADE
THE NIGHT AND BEGIN THE WHOLE
CYCLE ALL OVER AGAIN.
A NATURAL PREDATOR OF THE
CORN EARWORM MOTH IS THE
MEXICAN FREE-TAILED BAT.
JUST OUTSIDE OF UVALDE
IS FRIO CAVE.
10 MILLION BATS LIVE HERE.
EACH NIGHT THE BATS EMERGE
WITH ONE MISSION,
TO DEVOUR INSECTS.
THIS IS THE CLOSEST CORNFIELD
TO FRIO CAVE, WHICH MAKES IT
THE PERFECT PLACE TO STUDY
MOTHS AND BATS.
>> WE'RE JUST BEGINNING THIS
RESEARCH, AND THIS IS A PILOT
STUDY, SO WE WE'RE JUST GETTING
THINGS UP AND RUNNING.
THE, UHM...
HMM.
>> WHOA!
>> SO THE THEORY OF OUR
RESEARCH IS THAT WE CAN
PERHAPS MANIPULATE THE AMOUNT
OF CROP DAMAGES THAT'S CAUSED
BY THE INSECTS, SCARE THE
INSECTS AWAY BY SIMULATING
ARTIFICIAL BAT CALLS,
BY PLAYING BAT CALLS OUT
ALL OVER THE CROP FIELDS.
MAYBE A PRACTICAL INSECT
CONTROL STRATEGY FOR
DECREASING DAMAGE CAUSED
BY THESE INSECTS.
>> IN TWO SEPARATE FIELDS OF
CORN BIOLOGISTS SET UP TWO
SETS OF INFRARED STROBE
LIGHTS, SYNCHRONIZED WITH
A LOW LIGHT CAMERA AND A
SPECIAL DEVICE TO RECORD
THE SOUNDS OF BATS.
>> WE'LL BE USING AN
ULTRASONIC RECEIVER AND THE
OUTPUT FROM THE ULTRASONIC
RECEIVER WILL BE RECORDED ON
THE VIDEO CAMERA AND THEN
WE'LL HAVE SIMULTANEOUS VIDEO
AND ACOUSTIC RECORDINGS OF
THE BAT FLIGHT.
THE VIDEO WILL CAPTURE
SEVERAL SUCCESSIVE IMAGES OF
THE SAME TARGET AND THEN EACH
FRAME WILL BE A CONTINUATION
OF POINTS ALONG THAT FLIGHT
TRAJECTORY.
>> OVER AT THE OTHER SITE,
THE CAMERA SET UP IS THE SAME
BUT WITH THE ADDITION OF
ULTRASONIC SOUND.
>> RIGHT NOW, WE'VE GOT ON
EACH LIGHT POLE, WE'RE GONNA
HAVE TWO SPEAKERS FACED APART
SO WE'RE BASICALLY GONNA
HAVE THE ULTRASOUND BEING
BROADCAST IN FOUR DIRECTIONS
OUT ACROSS THIS ONE ACRE
PLOT OF CORN.
AND WE'LL BROADCAST THESE
ULTRASONIC SIGNALS ALL NIGHT
LONG OVER THIS FIELD.
(sounds bat chirping)
THIS IS THE ULTRASONIC DETECTOR.
WHAT YOU'RE HEARING WHEN I DO
THIS, THE CHIRPING, THAT IS
THE ARTIFICIAL SOUND.
PROBLEM WITH THEM THESE ARE
VERY MONOTONOUS AND REAL BAT
CALLS VARY IN FREQUENCY
AND IN DURATION AND IN
REPETITION RATE AND THE NEXT
MONTH OR SO PAUL IS GOING TO
WORK ON GETTING US A BETTER
ELECTRONIC BAT MIMIC.
>> PAUL SCHLEIDER IS AN
ELECTRICAL ENGINEER WHO BUILT
MANY OF THE COMPONENTS OF
THE SYSTEM AND DESIGNED THE
SOUND OF THE BROADCAST.
(chirping sounds)
>> BATS USE ECHOLOCATION WHEN
THEY HUNT FOR INSECTS.
THIS IS THEIR SEARCH CALL.
(chirping sounds)
WHEN THEY LOCATE AN INSECT,
THE CALL SPEEDS UP, AS THEY
ZERO IN ON THEIR PREY.
(chirping sounds)
THE HEARING OF THE CORN
EARWORM MOTH IS ALSO TUNED
TO THIS FREQUENCY AND WHEN
THEY HEAR A BAT, THEY TAKE
EVASIVE ACTION.
BY THE TIME THE TEAM RETURNED
A MONTH LATER PAUL HAD
ASSIMILATED BOTH TYPES OF
CALLS INTO THE BAT BROADCAST.
>> WE'RE NOW CAPABLE OF
BASICALLY SIMULATING THE CALL
REPERTOIRE OF THE BATS;
THE APPROACH, THE FEEDING
BUZZES, AND WHAT I'VE GOT ON
RECORDING RIGHT HERE IS A
VERY, VERY GOOD FACSIMILE OF
THE CALLS THAT BATS ACTUALLY
MAKE AS THEY SEARCH FOR,
FIND AND FEED ON INSECTS.
OUR HOPE HERE IS NOT ONLY TO
FOOL THE MOTHS INTO THINKING
THAT THERE ARE BATS OUT HERE
FORAGING BUT TO FOOL THE
OTHER BATS AS WELL AND TO
BRING OTHER BATS INTO THE
AREA SO THAT THEY'LL ENHANCE
THE FEEDING ACTIVITY.
>> CORN EARWORMS ALSO
INFEST COTTON.
WHEN FOUND HERE, THEY'RE KNOWN
AS COTTON BOLLWORM MOTHS.
WHEN A FIELD BECOMES INFESTED,
FARMERS OFTEN USE PESTICIDES
TO SAVE THEIR COTTON.
>> WITH FIELD CORN, ONCE THE
PLANTS ARE GROWING,
NO PESTICIDES ARE USED.
THE AMOUNT OF CROPS THAT THE
FARMERS LOSE DEPENDS ON THE
APPETITE OF THE CORN EARWORM.
>> WE KNOW WE HAVE SOME
DAMAGE, IT'S JUST HOW MUCH.
SOME YEARS CAN BE WORSE THAN
OTHERS, THE NUMBERS CAN GET
PRETTY HIGH AT TIMES.
I'D SAY MAYBE 30 DOLLARS
AN ACRE, MORE OR LESS.
(corn harvester machinery sound)
THIS YEAR WE'LL HAVE CLOSE
TO 400 ACRES OF CORN.
>> THAT'S 12 THOUSAND
DOLLARS THAT RAY KING WON'T
SEE WHEN HIS TRUCKS UNLOAD
AT THE SCALES.
>> WE NEED ALL THE HELP
WE CAN GET.
>> HELP COULD COME WITH THE
USE OF ULTRASOUND.
>> THE RESULTS FROM THE
EXPERIMENTAL PLOTS WHERE WE
PLAYED THE ULTRASOUND,
INSECT ACTIVITY WAS REDUCED
SUBSTANTIALLY, ON SOME
EVENINGS AS MUCH AS 70 PERCENT.
THE BAT BEHAVIOR WAS EVEN
MORE DRAMATIC.
WE INCREASED THE FORAGING
ACTIVITY OF REAL BATS,
SEVERAL FOLD OVER THE
TREATMENT PLOTS WHERE WE WERE
PLAYING THE EXPERIMENTAL
ULTRASOUND.
SO IN EFFECT THE RESULTS OF
THE EXPERIMENT LOOK REALLY
GOOD, WE GET A DOUBLE WHAMMY,
WE REDUCE THE INSECT ACTIVITY
AND SUBSTANTIALLY ENHANCE
THE ACTIVITY OF THE BATS
WHICH ARE COMING DOWN TO
FORAGE ON INSECTS.
>> ENHANCING PEST CONTROL
WITH GREATER EFFICIENCY
AND SAFETY.
BETTER FOR THE ENVIRONMENT.
CHEAPER FOR FARMERS
AND CONSUMERS.
COULD THE NEXT WEAPON IN THE
FIGHT AGAINST INSECT PESTS
BE THE VIRTUAL BAT?
>> LOVELY GARY,
DO IT AGAIN FOR ME!
>> IT MAY TAKE SOME TIME
BEFORE THIS TECHNOLOGY CAN BE
APPLIED TO LARGE FIELDS OF
CROPS, BUT IN THE MEANTIME,
THE RESEARCH GOES ON.
>> UHM...
ARE YOU SURE IT'S ON?
(sound of bats flying)