Exploration of biological control agents for the management of white-backed planthopper, Sogatella furcifera (Horvath) (Homoptera: Delphacidae), in rice in Myanmar | |
| Author | Mu Mu Kyaw |
| Call Number | AIT Diss. no.AS-03-04 |
| Subject(s) | Biological pest control agents--Myanmar Rice--Diseases and pests--Myanmar |
| Note | A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Technical Science, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Dissertation ; no. AS-03-04 |
| Abstract | This study was conducted to explore the potential of natural enemies for the control of one of the most serious rice pets in Myanmar, Sogatella furcifera (Horvath) (White-backed plant hopper - WBPH). The study consisted of an extensive field survey to record and gather natural enemies that suppress WBPH in rice Ecosystems and to determine their abundance, predation potential and effectiveness on the suppression of white-backed planthopper populations in cages and the field conditions in myanmar. This study was conducted during January to December 2002. Field survey conducted in two townships, Hmawbe and Pyinmana found fifteen predators (2 Odonata, 3 Coleoptera, 1 Orthoptera, 3 Hemiptera, 2 Hymenoptera, 3 Araneae, 1 Dermaptera) and one nymphal and adult parasite (1 Hymenoptera) of WBPH. Population of Pardosa pseudoannulata (wolf spider) was the highest in both ecosystems. The other most abundant natural enemies were micraspis discolor (ladybird beetle), Paederus fuscipes (rove beetle), while the lowest was proteus simulans (earwig). The population of WBPH was greater in Pyinmana than those in Hmawbe. The second experiment examined the preference of 13 selected insects as predators or parasites on WBTH in the screen house. Number of dead WBPH was recorded at 10 and 20 days after infestation. It was found that the predation rate of Camponotus sp. on WBPH was highly significant at 0.01 level. Feeding preference of camponotus sp., P. fuscipes, P. pseudoannulata, Hydrometra sp., Cytorhinus lividipennis, Casnoidea indica, Micraspis discolor and Tetragnatha sp. was more the preference of limnogonus fossarum, Ropalidia fasciata and Gonatocerus sp. on WBPH attack in treatments with Camponotus sp., P. susciped, P. pseudoannulata, Hydrometra sp., C. lividipennis, C. indica, M. discolor and Tetragnatha sp. Field experiments were conducted at Central Agricultural Research institute, Yezin, Pyinmana, Myanmar to assess the efficacy of eight predators chosen from cage experiment under the field condition. Number of survived WBPH, plant damage score caused by WBPH at 20 and 30 day after infestation and rice yield were recorded. Number of WBPH survived and plant damage score of all treatments with predators were significantly different from control 1 (Without predators and with WBPH). There were significantly higher yield losses due to WBPH when compared to the control without both WBPH and predators. This treatment gave a higher grain yield than the rest. Treatments with Camponotus sp. and P. pseudoannulata had excellent control of WBPH, and had lowest plant damage score and higher grain yields when compared to other predator treatments. Number of WBPH survived showed negative effects of grain yield and positive effects on plant damage score. In all predator treatments, Camponotus sp. and P. pseudoannulata resulted in higher grain yield and gross income than the rest of the predators. Hence, Camponotus sp. and P. pseudoannulata are considered the most effective agents for controlling WBPH. Grain yield and total gross income showed that the control treatment without WBPH was superior to all other treatments. Use of Camponotus sp. and P. pseudoannulata showed promising results. Under the natural conditions, these predators eliminate the cost incurred on collecting, mass rearing and introduction of predators to the crop and hence world increase both gross income and profits from the rice crop to the farmers in Myanmar. Although the gross income and profits were lower in treatments having C. indica, Tetragnatha sp. and C. lividipennis, their contribution is important to suppress WBPH under natural conditions. |
| Year | 2003 |
| Corresponding Series Added Entry | Asian Institute of Technology. Dissertation ; no. AS-03-04 |
| Type | Dissertation |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Agricultural and Aquatic Systems(AS) |
| Chairperson(s) | Ranamukhaarachchi, S.L.; |
| Examination Committee(s) | Yakupitiyage, Amararatne;Rakshit, Sudip K;Banpot Napompeth; |
| Scholarship Donor(s) | The World Bank JJ/WBGSP; |
| Degree | Thesis (Ph.D.) - Asian Institute of Technology, 2003 |