'Golden' menace in Ifugao rice terraces Item Type article Authors Dancel, K. T.; Joshi, Ravindra C. Download date 26/09/2021 16:42:43 Link to Item http://hdl.handle.net/1834/35009 Special report 'Golden' menace in Ifugao rice terraces If the golden apple snail (GAS) were real B y for natural predators, modification of wa­ "gold", farmers in the Ifugao Rice Terraces K.T. Dancel1 and R.C. Joshi2 ter management techniques, development (IRT) would have been grateful to those1Office of the Deputy Executive Director for R&Dof crop protection practices that can be who brought it to the world-renowned spot 2Crop Protection Division timed to increase GAS mortality, and dis­ in the Philippines. Philippine Rice Research Institute covery of more palatable food recipes for Now one of the major rice pests in the M aligaya, M uñoz, 3 110 N ueva Ecija human and animal consumption. IRT, GAS has been significantly reducing Philippines the current yield of about 1.34 tons per ha Tracing the origin annually, which is barely enough to feed Earlier studies conducted by researchers the families for the whole year. from the University of the Philippines at Scientifically known asPomacea Los Banos (UPLB) and DA-PhilRice claim canaliculata (Lamarck 1822), GAS has that GAS was introduced in the Philippines been known in the Philippines to habituate between 1982 and 1984 from Taiwan, only the lowland areas and its reproduc­ Florida, and Argentina as food and protein tion is limited by low temperature, high el­ source of Filipino farmers. Because of this, evation, and salinity. Surprisingly, a group GAS was massively cultured and distrib­ led by Dr. Ravindra Joshi, a crop protec­ uted in different lowland areas of the coun­ tion specialist at the Department of Agri­ try and now has become one of the major culture-Philippine Rice Research Institute pest problems in rice production. (DA-PhilRice) discovered that GAS can In Argentina. GAS is not a problem survive in cool, elevated areas as demon­ according to Dr. Nestor Cazzaniga of the strated by a large number of GAS in the Universidad Nacional del Sur Departmento IRT, which is 4,000-5,000 ft above sea de Biologia. Although rice is not a staple level. food in Argentina, large portions of lands Unaware of the possible threats posed are planted to rice because it is exported. by GAS, rural folks in the IRT brought it Because its production is highly mecha­ from the lowland areas for human and ani­A female golden apple snail can lay about nized, 25- fields are properly leveled and wa­ mal consumption and for weed control.320 strawberry pink eggs at one time. Theseter is well-managed and controlled, mak­ Rice seedlings raised in the lowland areas, eggs mature in about 10-15 days ing it less prone to GAS infestation. which could have borne eggs or hatchlings, The first report on GAS infestation in were also transplanted in the IRT particu­ the Philippines came out in 1986 when larly in the upper terraces. GAS was spread EDITOR'S NOTE about 300 ha of irrigated lowland rice fields all over the IRT through the terrace irriga­ in Region 2 were heavily damaged. In the You may well ask why a rice paper in an tion system. same year, farmers in the IRT started to aquaculture newsletter? "We need a new notice the same. By 1988, GAS has already The International Rice Research Insti­ solution to the old golden apple snail prob­ tute (IRRI) library website http://www( . lem, and an integrated approach with damaged about 4% of the country's total ricelib.irri.cgiar.org) shows some 65 refer­ fishfarming may be the answer," explains rice area and in 1990, the damage reached ences indicating that GAS research has Dr. Ravindra Joshi, a PhilRice research 11%. been concentrated in the lowland areas. As fellow, when he visited SEAFDEC/AQD on a result, most of the control measures es­January 25. Me presents this problem inGAS invasion in neighboring tablished cannot be applied in the IRT be­ the hope that researchers on aquaculturecountries cause of its unique characteristics. Currentmay become interested enough to workA study conducted by Drs. Yoichi Yusa and with him. Dr. Joshi can be reached at: GAS research in cool, elevated areas looks Takashi Wada of the Kyushu National Ag­ <[email protected]> or <joshiravi ricultural Experiment Station shows that the at possible control measures such as the [email protected]> Telefax (63-02) 843 5122 of indigenous plants as attractants, search next page SEAFDEC Asian Aquaculture Vol. XXII No. 1 January-February 2000 11 golden kuhol menace by dancel & joshi Handpicking is still one o f the most practical methods in controlling The golden apple snail can damage newly planted rice seedlings the golden apple snail population overnight introduction and culture of GAS in Japanan province, an experiment on the usetion of of the government. started as early as 1964 when a companyfishes such as black amur and tilapia in In 1991, it was introduced in Cambo­ introduced it as an aquarium pet. It becamecontrolling GAS shows considerable reduc­dia through refugees who returned from popular as food in the early 1980s buttion the in GAS density to as high as 84% fromThailand. Farmers in Takeo intentionally production later declined because peoplesummer to autumn and 64% from winterraised it in their fields as food, just as they did not like the taste of the snail. It was to spring. normally did with the native snailsPila ( later disposed into rivers, ponds, creeks, and It was only in 1990 that GAS was firstsp.). Since the native snails do not damage paddies. Damage to rice was reported in detected in a household tank in Malaysia.rice, farmers assumed the same for the 1984 and in the same year, GAS was de­Its origin was unknown. Based on the size,GAS. One of the most popular attractants clared as a quarantine pest by the Ministryit was concluded that GAS had been thereused is the dragon bone plant, which is re­ of Agriculture, Forestry and Fisheries. Still,for some three to four years earlier. Theported to contain toxins. aquarium shops in Japan continued todisperson im­ of GAS in Malaysia was rela­ In Australia, the software package port and sell apple snails as pets. Naturaltively slow because of the coordinated ef­CLIMEX was used in matching the cli­ predators currently used include the waterforts of relevant authorities. Upon discov­mates of geographical regions whereP. birds, fish, turtles, fireworm larvae, and ery of the GAS, the Department of Agri­canaliculata is known to occur with that crabs. culture formed the GAS Task Force at theof other regions in the world. The match­ In Thailand, it was introduced in 1982national level. Small working committeesing showed that large regions within India. from Japan and Taiwan. Mainly used aswere also formed at the district level to China, and Australia are at risk for future decoration in aquariums, GAS rapidly mul­monitor the status of infestation and resultsGAS invasion. tiplied and eventually produced excessof control measures employed. In selected stocks, which were thrown away andareas, effective control measures includeControl methods reached canals and rivers. The first GAS the use of salt water, pesticides, snail metal The GAS are most often found in moist outbreak was recorded in 1988 southtraps, of and natural predators such as ducks.soils with vegetation, commonly in rice Bangkok. Several indigenous plants thatAn on-going trial on the integration ofpaddies. fish They appear to be very still as they have been used to control it include thein rice culture has reported promising re­tightly stick to the stems of rice plants and golden dewdrop Duranta( repens), mafia sults. burrow into the clayey soil when soil mois­ nok kumAmmannia ( bacifera), pla khum A year later after GAS was discovered ture declines. Their clustered pinkish eggs dee kwai, and soapberry treeSapindus ( in Malaysia,Pomacea sp. was found in aremain pasted on leaves and stems. Tiny semarginatus). farmer's fishpond in Lao PDR. GAS startedand fragile as they appear, the GAS have In Vietnam, it was introduced in 1988to invade neighboring fields when heavyhigh survival rates. An experiment con­ from South America and declared as a quar­rains flooded the pond causing it to over-ducted by the group of Joshi demonstrates antine pest in 1993. By 1997, it has alreadyflow. It was in 1993, when it damaged aboutthat GAS can still survive during fallow spread to 7 out of the 61 provinces. In Nghe5 ha o f rice that it was brought to the atten­ page 31 12 SEAFDEC Asian Aquaculture Vol. XXII No. 1 January-February 2000 • Testing with different immune functions role of vitamins ... from page 10 must include the mechanism by which a single nutrient accelerates different biological functions The safety level of vitamin E has to be• Safety levels of different vitamins must determined before administration (Waagbobe determined before administration 1994). According to Pulsforde t al. (1995), • For antioxidant vitamins, care should be the phagocytic activity of kidneytaken to avoid losses due to atmospheric macrophages in flat fishes were enhancedoxidation and water leaching by using when the fishes were fed higher amountsthe recommended type such as phos­ of vitamin E. phate esters of ascorbic acid • More work is needed for vitamins C and Conclusion E supplementation beyond minimum di­ Still no clear conclusions can be drawn withetary requirements to clarify the benefits respect to vitamin nutrition and fish immu­to fish health. So, metabolism of nutri­ nity. So, attention should be given to tionalim­ C and E forms needs further in­ prove the earlier recommended levels forvestigative biochemistry different vitamins.