The The CoquiCoqui Frog InvasionFrog Invasion

Arnold HaraArnold HaraUniversity of Hawaii at University of Hawaii at ManoaManoa

College of Tropical Agriculture and Human Resources College of Tropical Agriculture and Human Resources Hilo, HawaiiHilo, Hawaii

What will this presentation cover?* Invasive species crisis in Hawaii* Impact on Hawaii’s environment* Basic Biology* Life cycle* Video of single calling male* Color variation* What do they eat?* Who has more coqui frogs,

Hawaii or Puerto Rico?* Non-Chemical Controls* Chemical Controls* The Reality

= Any foreign, exotic, or alien species thatspreads aggressively to causecommercial, agricultural, environmentalor human health harm.

What is an Invasive Species?

Invasive Species Crisis in Hawaii

Recent Invasive Species Affecting East Hawaii

Nettle caterpillar 2001(palm, ti-leaf, iris, mondo)

Cotton lace bug 2001(hibiscus, eggplant, orchid tree)

Cycad scale 2000(sago palm, queen)

Cardin’s whitefly 2003(fiddlewood, citrus, plumeria)

Coqui frog 1990’s

Noisy!!!

Giant Whitefly2002 (hibiscusfiddlewood)

Bearded!

Stinging!

Little fire ant 1999

Stinging!

Dec 2003

By Kim Tavares, BIISC

Beneficial Insects:nativespollinators parasitoidspredatorsorganic feeders

People’s sleepReal Estate + and -Developing vacantproperties reduce froghabitats. No sale due to coqui.

Impact of Coqui FrogsFrogs will infest areaswith >60 inches of rainfalland from sea level to4000 ft. elev., almost theentire East Hawaii.

IrrigatedlandscapesIn West Hawaii

*Male coqui frogs provide parental care by guarding eggs from predatorsand keeping the eggs moist.

Basic Biology

*Unlike insects with hard outer shell, coqui take in water & oxygen throughtheir very thin, fragile skin.

*Internal body structure of a coqui frog is similar to humans and possesssimilar organs including a heart, lung, liver, pancreas and kidneys.

*Coqui frogs live on a diet of insects.

*Coqui frogs are cold-blooded in that their body temperature dependson the temperature of the surrounding environment.

*LOUD calling sounds are produced in the same way as humans yell,by forcing air from their lungs over their vocal cords, located in the throat.

*No tadpole stage, direct development from egg to frog.

*No tadpole stage; no need for water, just moisture.*Males guard eggs and keep them from drying out.

Mature adult

Froglet

Egg cluster size: 34 (17-75)Clusters/female/yr: up to 26Eggs incubation: 14 -17 days

Life Cycle of the Coqui

Eight monthsfrom egg toegg-laying adult.Adults live aslong as 4 to 6 yrs.

Cluster of eggs

The vocal sac inflate and act as resonating chambers, amplifyingthe call. Two types of calls:1) mating or advertisement call2) aggressive or defensive call – defend territory from other males

Vocalizing male coqui frog

vocal sac

J. Ballauer

Are these all Coqui frogs?

Brown w/o stripe Brown w/stripe &mottling

Lighter brown w/stripe& yellowish mottling

Light brown w/stripe& yellowish mottling

Light brown w/stripe & smooth blend of yellow

Light tan w/ stripe Light tan w/stripe &tinge of yellow

Light yellow w/stripe& tan mottling

Yellow w/stripe & dark brown mottling

Golden yellow w/stripe& tan patches

Brown w/o stripe &tan grey mottling

Tan w/o stripe &brownish mottling

eggs

Skin is very thin and sensitive to chemicals, heat or cold

1 to 2 days 3 to 4 days

S. Chun13 to 14 days old10 to 11 days8 to 9 days

5 to 6 days

Coqui Frog Egg Development (Days after laid)

Frog Hatch

S. Chun

Nesting sites are hiding places in curled leaves or debri that is dark and holds moisture

Nesting Sites are Abundant in Hawaii

Fallen heliconia leaf

Ti- leaf on plant

Frog snaps at grasshopper!

J. Ballauer

What do they eat?

*Cannibalistic - Eat themselves and their eggs!*Starve over 3 months and live on moisture only!

Who has more frogs, Hawaii or Puerto Rico?

*Adult population in Hawaii is 4 to 6 times greaterthan Puerto Rico.

*At Lava Tree State Park number of adults andjuveniles is estimated at greater than 10,000/acre.

Why is Hawaii’s Population Higher than Puerto Rico?

• Lack of Predators (snakes, large spiders, lizards and owls in Puerto Rico)

• Denser vegetation with more nesting and retreat sites!

• More insects, more food supply!

Typical Coqui Frog Habitat in Puerto Rico

Hawaii’s forest has more retreat & nesting sites

Exposed roots of trees provide retreat sites

Denser vegetation

Lava rocks also provides retreat sites

Lava Tree State Park

Capturing Hand capture; requires practice*Cultural Habitat modification. Re-landscape to

minimize retreat and nesting sites*Trapping PVC traps*Temp.

Heat Hot water shower or vapor heat (113o F)Cold In reefer for 36 – 38o F for 6 hours

*Biological Predators and diseases (chytrid fungus)Behavior Simulate male calling to attract femalesGenetic Insert lethal or sterilizing gene into

*Further discussion coqui frog population (long term research)

Non-Chemical Controls

Lava Tree State ParkHabitat Modification and Native

Plant Replant ProjectBefore

During

Inmates from Hawaii CommunityCorrection Center provided labor.

After

Volunteers from Malama ‘0 Puna replantedwith donated native plants.

Coqui Frog Ground Zero!

Collaboration:County of Hawaii, DLNR, HDOA, USDA, UH

Covering rocks with cinders to seal habitat sites for frogs

Frog habitat

Frog habitat

LavaTreeStatePark

Collaboration:County of HawaiiDLNRHDOAHCCCMalama ‘O PunaUSDAUH

PVC Traps

* 1” PVC provides nesting site*Trap efficiency is 19-28% in

tests at Lava Tree State Park.*PVC needs to be weathered.*Mass trapping will be tested.

1” PVC trap with “T” fitting

1” PVC w/eggs &male

Hot Water Shower for plants*Treated at 113 F for 3 min kill frogs.*Plants are not detrimentally affected.*Plants are treated immediately priorto shipping.

*Hot-water shower system installedat the Division of Forestry & Wildlife,Tree Nursery in Hilo for forestseedlings.

Instant water heater

TempController

Eggs Dipped in Hot Water109o F for 3 min

Treated(Cooked)

Untreated(Uncooked)

Temp & Time Required to Eliminate Egg Hatch109o F <3 min113o F <2 min

Chemical ControlsCaffeine Not Available. Emergency registration has expired.

Hydrated Hawaii Dept. of Agriculture has applied for specialLime emergency registration. Legal to apply as a soil

amendment. A 25-50 lb per 100 gal mixture kills frogs asa drench application to the ground during the day.

Citric Acid Legal and effective in tests at (1.3 lb /1 gal. 16%). Burns certain foliage and flowers (ferns, papaya, mock orange, orchids). Application in the evening when frogs areactive.

Pyrethrins Will drive frogs out of hiding; they often recover from this(Raid H&G) toxicant.

Citric Acid and Pyrethrins: 8% citric acid plus pyrethrins is effectiveand will not injure plants.

Citric AcidDegree of tolerance of tested plants to 16-25% citric acid sprayTolerant to Citric Acid:

Palms: Dracaena fragransAreca Dracaena warneckeiFishtail PhilodendronRhaphis SyngoniumParlor Ti plantPhoenixTriangle

Sensitive to Citric Acid:Anthurium Mock orange Bromeliad Passion fruit Citrus PapayaCalathea StreptocarpusGuava orchid Leather leaf fern

Washing with water one hour after spray will eliminate burning.

Also sold in dry form 5 lb = $9.00

Experimental Drench Application of Hydrated Lime

Effective day treatment by concentrating high volume applications to retreat areas on the ground.

Koa’e (Kapoho) Community Association 1000 gallonDrencher with a high volume firefighting pump.

High volume firefighting nozzle

Biological Control of the Coqui Frog

Predators:

Hawaiian Hawk?

Mongoose?

RatConfirmed!

Others?

? ?

Confirmed!

Brown Tree Snake now has lots of coqui frogs as prey or food to thrive in Hawaii!

Hawaii 2050

The Reality*Coqui frogs will continue to expand on the Big Island!*No known effective biological control agent (predator,

parasite, disease).*Coqui frog populations will be limited only by lack of food

supply and nesting sites.*Some community groups have been successful in controlling

coqui (Kohala, Pahala, Kapoho, Komohana Gardens). The sooner 1 or 2 frogs are captured in a new area, the chance for success is greater.

*Government (County, State, Federal), private landowners, and plant nurseries must do their share in coqui control on their property and plants for sale.

AcknowledgementsAcknowledgementsFor assistance:Joshua Ballauer

Francis BenevidesCynthia CareyClive CheethamStacey ChunEunice DomingoMyrtle HaraTrent HataChris JacobsenMeg JonesDennis IdaBeryl IraminaRyan KanekoCurtis KataokaIrving KawashimaBilly Kenoi

Eloise KilgoreMayor KimAngel MagnoBill MautzLarry NakaharaRuth Niino-DuponteTim OhashiKyle OnumaLance OgataRosey RosenthalRene SiracusaRick SpearesKim TavaresMarcel TsangShayne VeriatoLarry WoolbrightTHANK YOU!!!