HAWAII'S HATED FROGS Tiny invaders raise a big ruckus -BY JANET RALOFF
uerto Rico's beloved mascot is a miniature tree don't have lots of calling insects, if you go to where the frogs aren't at night, it's dead quiet," observes herpetologist William frog named for its distinctive call: ko-KEE. All J. Mautz of the University of Hawaii at Hilo. "Then enter an area night long, choirs of love-starved males sere- with a big infestation, and you hit this wall of sound." nade would-be mates, who respond with quiet But it's not only the noise that has federal officials up in arms. The proliferating coqui and greenhouse frog populations on guttural chuckles. "To me, it's pleasant-just islands that evolved in the absence of amphibians threaten to likeP birds singing," says Bryan Brunner, a University of overwhelm native ecosystems. That's why USDA has teamed up with the State of Hawaii and FWS to control-and, if possible, Puerto Rico plant breeder in Mayaguez. "Here, every- eradicate-the tiny hoppers. body loves the coquies." And legend has it, he says, that coquies- The scientists are developing tools, including caffeinated sprays native only to Puerto Rico-die of sadness when removed from and scalding showers, for holding back what they see as an their island. advancing plague of frogs. Hawaiians are lamenting that that fable isn't true. In the mid-l980s, potted plants from the Caribbean began HOPPING HATCHLINGS For the many frogs and toads that arriving in Honolulu carrying frogs. Some were 5-centimeter-long spend their youths as tadpoles, early survival and development coquies (Eleutherodactyluscoqui), and others, a quieter and even depend on access to water in which they can swim and feed. But tinier cousin, the green- for members of Eleuth- house frog (Eleuthero- dactylus, the world's dactylus planirostris). largest genus of verte- These stowaways reveled brates, young emerge from in their new setting: a the egg or from Mom as largely amphibian-free tiny, fully formed frogs. land with a bountiful This opens up a broader smorgasbord of insects, range of habitats than is tiny spiders, mites, and available to tadpoles. other delectables-and no Water-soaked moss deco- snakes, tarantulas, or I rating a potted plant will other natural do, as will the humid By the end of 1998, - - packaging around plants, seven populations of 1 or a spoonful of water coquies had established themselves on the Big 1 Island of Hawaii, recalls Eggs, which coquies Earl Campbell of the Fish and greenhouse frogs lay and Wildlife Service (FWS) in Honolulu. And the number has on the soil, are hard to detect. Normally, male coquies guard rocketed. "We now have over 400 populations on the Big their eggs for 2 to 3 weeks-not to fend off predators so much Island," reports Campbell, the FWS Pacific Basin coordinator as to keep them moist, explains ecologist Larry Woolbright of for invasive-species issues. He also notes a few coqui outposts Siena College in Loudonville, N.Y. Like a sponge, Dad's under- on Maui, Kauai, and Oahu. belly efficiently absorbs water and then releases it onto the eggs. Local wildlife-protection officials have no trouble recogniz- But fatherless eggs could survive transit to Hawaii if they're ing new coqui populations. On the Big Island, public officials attached to damp plant material, he says. receive about 10 complaints a day from homeowners who, unlike At hatching, baby coquies are green and only 5 millimeters Puerto Rican residents, get fed up with the racket, notes Tim J. long, about the size of a rice grain. Because they're nocturnal Ohashi of the Department of Agriculture's Wildlife Services and don't begin bellowing their telltale serenades until they're Branch in Honolulu. about a year old, the youngsters tend to remain undetected, A backyard full of the frogs can reach 70 to 90 decibels-the Woolbright says. + volume of moderate-to-heavy street traffic or the din in neigh- The frogs' catholic tastes facilitate their integration into the 2 borhoods along aircraft takeoff and landing corridors. Indeed, Hawaiian environment. After sleeping under leaf litter all day, 75 decibels is the maximum sound volume that people can the tiny amphibians come out after dark to dine. Some stay near $ encounter at work throughout their careers without risking hear- the ground, while others ascend into a tree's canopy. Then they 2 ing loss (SN: 5/22/82,p. 347). sit patiently and await the arrival of the evening's entrees-insects Hawaiians aren't used to such nighttime noise. "Because we or any other small creature that crawls within pouncing range.
JANUARY 4, 2003 VOL. 163 11 Hawaii'sotherCariiintrudem,the~ousefrogs,also permissiontotry a 2-percent-dkine solution as an experimen- concernscientists. So far,thefve conducted nlatively Ihstud- tal pesticide sprayfor 1year. iesofthose@et~ts,whichhaveprwed~dttohd Pitt says that tests on small plots ofinkted greeneryp d and count. thatthesprayisindeedaan~~ude.ifyouwiU'Bestof Though axpies invaded Florida roughly a century ago, they all, he says, caffieine exhibited %ry Ih impacts on other, non- haven't spread far there, Campbell notes, probably because they taqpt 0- For instance,insect populations in sprayed had plenty of competitorsfor foodand shelter. plots declined a bit, but within a week had rehmed to normal. But in Hawaii, heobserves, 'we don't have as many creatures Thetests turned up another potential ben& Garden slugs,the as doecosystems on the mainland, sowe stillhave a lot of what ~eoftheo~dind~,~tothetheofrfaceaftreatedmd people might term open niches." When the coquies and green- died (h#pJ//bcimanccas.420020706~asp). house frogs arrived,they set claim to onesuch niche. In September,the temporary EPA permission for testing expired. USDA has now applied for a &year extension to con- BEYOND THE RACKETDuring matingseason-which can du&MerreseaFehthatmighte~en~leadto~e'sfed- run year round, dependingon theclimate-crooning males eral approval as a fiosantrol agent. from ground to treetops produce a three-dimen- 'But we don't want tolimitoursehrestoone tool,- sional fog of sound. To drown it out at bed- A Pitt says, so his laboratory has continuedtest- time, many Hawaiiansrun air condition- A - L ing other unusual candidatehgicides. It ers as a source of white noise. Others recently un-red one that's so tx& a don earplugs. foodproductthatEPAdoesn'tregulate It's gotten so bad, Ohashi notes, , it. It's citric acid, the primary con- that realtors have been forced to stituent of lemonjuice. disclosethepresence ofooquieson Preliminary tests, begun in listed properties, much as they August,usedacitric-acidformu- would evidenceoftermiteswater I lationroughlycomparabletodm- damage, or structural tlaws. ble-strength lemon juice. The But of even biirconcern to ' spray isn't quite as potent as caf- USDA and Hawaii's Department I feineforkillingfrogs,PitttoldSci- of Agriculture is the frogs' em- cnaNcme.Nevwtheless,eadydata nomic threat to Hawaiian plant oncitricacidlmlcveryprombing," growers, notes Ohashi's colleague hesays,aandweseewrylittleimpact Will Pitt at USDAk WildlifeServices . on plants." research center in Hilo. Sales of In July, the Honolulu Star BuUdin orchidsandothertropicalplantsamount reported that the Hawaii Department of toa huge exportindustry. Buy- Agriculturehadfoundthathydratedlime,the ers on the Hawaiian islands 1 GOTCHA! -Falrfyindlscrlmlnate powder used toreduce the acidity ofsoil, also kills thatarestillfieeofcoquiesand I d~nnrmpuhw eat ,most anything frogs. Ohashi confirms this, but he points out that greenhouse frogs are now llke this bug. Matenters thelr range. I hydrated lime couldn't legally be used against frogs rejecting some potted plants I unless it were toreceivefederalapprwalas a pesticide. grown on the Big Island. It may not be long, Piit speculates, Andthat's unlikely, he adds. Man&wtwem don't view as worth- before the frog scare affkctsforeign trade or plant shipments while the prospect of carryiog out the necessary safety and &- to the U.S. mainland. Any impact on Hawaii's $80-million- cscy~heexplab,%ecausetheymakeenoughmoneyd- per-year cut-flower-export industry would be especially trou- ingitforits~urrentlylabeleduse.~ blesome. Pittsaysthatplantgrowem might also resist limebecauseit Rather than simply imposing a quarantineon plants in frog- can leave a white residue on treated plants. =Ifyou're an orchid infestedareasofHawaii,l'ittsays,~ent~eswantto grower selling $200 or$300plants, a littleleafspottingmay not o& gnmem tools for coping with the problem. The propod be dle,=hesays. al??eMlis remahblylow-tech. mdly,ddcentersareinvestigatinganexperi- Westarted, about2yean,ago,lookingattrapping-handcap mental nurserytechniqueto prevent the spread of@ in pot- tams-butitwasn0tataIlefiiective:saysPitr tedplantaEdBrodieofHawaii'sDivisionofpol.estryandWildlife So, CampbeQwhowasthen with USDA,beganscmm@d- in Hilo, for instance,has he-tuned an $11,000 computercon- the-sMfagenta that might poisonthe*withoutharmingtheir tdeddevicethatsprayshotwaterontoahpo#edplantsat ~nment.lstartedbylookhgathedidesforuseonoma- atimetoIdlpeets.A&miautesprayof46JOC(ll64P)waterloills mentals,probably2Oto25~0m~he~Nonekilled~any coquies and greenhouse frogs present. As a bonus, he says, at penniUed applicationrates. theeeatmcntkills~centipede8,andabOUt~else Then Campbellheard that acetaminophen-the active ingre!- in the soil except ants. dientinQlenol-works as a poison tocontroltheinvasivebmwn Brodie's lab includes a nursery for endangered and native tree snake on Guam(SN: 8/10/02,p. m.He redirectedhis atten- plants.Overthepast3years,workerstherehrrvetreatedupto tion to overthecounter drugs and food additives. Again, the 1,000plants a day withthehot-waterspray. Theonlydawnside resultswere abysmal-until hetested a popular formulation for mfaristhatorchidb~+bUttherestoftheplantd staying awake that contains &e. In Campbell's lab, coqui healthy. andgreenhouse frogs died quickly afterbeing sprayedwith a 2- percent-afkine solution,which contains a tar higher concen- CLOCK IS TICKING Other than noise pollution, the hgs' tration of dinethan coffee does. e&tonHawaiiishardtocharacterize,Campbellsaye.Ordi- narily, scientistsgauge environmental impacts by comparing KllLlNGTHEM SOFnYBecause oaffeinehas never been fed- befo~panddkdata onspeciesin a region invadedby analien. edlyappd as a pesticide, the Stateof Hawaiihad topetition InHawaii,howewr,therdslittlepre-invasiondataforrnostamas theEvvironmentalProbectionAgencyhpermieeiontoBqperiment nowi&stedwithaxpiesandgreenhousefrogs. I outdoon,withthean~stimulantTheagency~thestate Howewer,thedelmingnumbersoffrogainthoseareas J
12 JANUARY 4, 2003 VOL. 163 SCIENCE NEWS . . .-i, .. T-: ,, . <'. .-L,.2,.,-. ,,....* & ':.-, ..ii-ku convince Mautz that "there will be impacts," he says. He's par- could be amassing big colonies without anyone knowing it. ticularly concerned about the frogs' consuming insects now avail- "But what actually scares me the most about the frogs being able to birds. here," Mautz says," is that they'll be food for other invading ani- Woolbright agrees. His surveys of 20-m-square forest plots mals. . . . If we have this huge food base of frogs, it will be a par- in Puerto Rico have turned up an average coqui concentration adise found for invading snakes." Hawaiian ecologists have long of about 2 per square meter. But more important, he says, is the scouted for invading brown tree snakes, which occasionally stow number of reproductively mature adults. Typically, a 4-night away on planes landing in Honolulu. survey logs 40 adults in a 20- In theory, it's not too late to by-20-m plot. think about eradicating This summer, he set up sim- coquies, Mautz contends. ilar plots in Hawaii. During They could easily be hunted one 4-night census, "we got down. Even now, there are 200 adults in one plot," he told only several hundred reported Science News. populations, some with just a The abundance of coquies in few isolated animals. He esti- Hawaii probably traces to a mates that the frogs cover only lack of predators. Woolbright about 1,000 acres statewide. says that Puerto Rican coquies "If true," he maintains, "you are a dietary staple of rats, could apply a scorched-earth screech owls, cuckoos, snakes, policy to [routing] them" with tarantulas, and many others. caffeine or citric acid. Then During a typical night's survey again, he concedes, getting the of his plots in Puerto Rico, six political will to cut through to eight coqui predators show I the environmental red tape for up. "In our plots in Hawaii, we such dramatic action would be found none," he says. difficult. In Hawaii, "I estimate that Stall too long, Mautz warns, about 200 kilograms of arthro- I and it may be too late to do any- pods [such as insects and spiders] per hectare per year go to thing but learn to live with the noisy immigrants. "The way I see feed the frogs," Mautz says. "So, you now have an invader that's it," he says, "we've only got 5 years, maybe 10."
+ suddenly commanding a huge piece of the whole food chain." Indeed, Woolbright says, "I see no quick, clean, and easy way The open question is, he says, Whose dinner are coquies steal- to remove these frogs from sensitive island habitats like Hawaii." s ing? Start unleashing poisons, even one as mild as caffeine, and things The greenhouse frogs raise additional concerns. They fre- could get ecologically messy, he worries. quently turn up where coquies have settled, although their num- In the end, he suspects, "this just might turn out to be a situa- 4 bers appear relatively small. Campbell notes that this quiet species tion where [Hawaiians] will have to grin and bear it." rn
CANCER sometimes skip treatments, notes Stadey Philadelphia, Pa. L. Schrier of Stanford University. A pill- Protein vaccine based alternative would presumably be easier for patients to follow. attraction to the leukemia cells. Three The new medication, now designated as other patients in the group showed par- ICL670, binds to excess iron, and these By injecting leukemia patients with part of tial responses. complexes ultimately leave the body in the a protein found in greater abundance on Molldrem and his colleagues are now feces. Researchers in Italy compared cancerous cells than on healthy ones, testing the vaccine in 60 more leukemia deferoxamine mesylate with ICL670 in 71 hershave been able to induce some patients. -N.s. patients with an average age of 25. The patients' immune systems to fight this participants had a hereditary form of ane- blood cancer. ANEMIA mia called thalassemia that required them Jeffrey J. Molldrem of the University to get transfusions every 3 weeks. They of Texas M.D. Anderson Cancer Center Getting the iron out had been receiving deferoxamine mesy- in Houston and his colleagues fashioned - late via a needle drip placed under the skin the cancer vaccine from a piece of pro- While transfusionsare lifesavers for many for 8 hours a night, 5 nights a week. teinase 3, a compound overproduced by anemia patients, they introduce excess iron Periodic testing of iron content in the malignant blood cells in leukemia into recipients. This overload can damage patients' blood and liver over a year showed patients. Earlier research suggested that the liver, pancreas, and heart. A new pill that ICL670 cleared transfusion-caused the piece, called PRI, stimulates produc- that reverses this process may vastly iron overload as well as deferoxamine tion of immune system T cells that specif- improve the lives of anemia patients, a new mesylate did, says study coauthor Anto- ically target proteinase 3. study shows. nio Piga of 'knn University. Molldrem's group identified 15 patients The standard drug for removing iron Ifthe work is confkned, ICL670 '%odd with leukemia that had resisted other from the body is deferoxamine mesylate. represent a major clinical advance for treatment. Each patient received three PRI It chemically captures, or chelates, excess patients with sickle-cell [anemial'' and 0th- injections, each separated by 3 weeks. In iron but must be given intravenously or by ers who need regular blood transfusions, five people, the leukemiawent into remis- injection. The chief problem with defer- says Ronald Hoffman of the University of sion and their T cells showed a strong oxamine mesylate therapy is that patients Illinois Medical Center in Chicago. -N.s.
JANUARY 4. 2003 VOL. 163 13 Hawaii's Hated Frogs
Janet Raloff
Science News, Vol. 163, No. 1. (Jan. 4, 2003), pp. 11-13.
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