Spatial dynamics of teak defoliator (Hyblaea puera Cramer) - Cochin ...

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-.-.-._ --- _--. Black light tube --._ -._ _ _. Baffle ......__.-•._-._.-.--- _- Tube holder - " --.---- ,,- Collectionfunnel ..."..__ __._._. Collection tube - _.__.._.__._- Walk-in cage "....__._..._._....- Battery box Fig.7.1. Diagram showing the prototype of the light-trap. (3) The Solar Photo-voltaic System The Solar photo-voltaic system (SPV) system was developed with the help of ANERT (Agency for Non-conventional Energy and Rural Technology), Trivandrum. It consists of (i) 4 numbers of 30W (nominal) SPY panels, (ii) a l2V 60 AH storage battery, and (iii) an electronic control unit. The electronic control unit has two sections, namely charge controller and inverter. The charge controller ensures that the battery is neither over-charged nor over-discharged, with cut-ofT voltages at B .8V and 1O.5V respectively. The inverter operates at 20 kHz with a secondary voltage of 200V on load. The Solar panels are mounted on a steel pole, 2.6- ID in height and 7.5- cm. in diameter. The battery and electronic control unit are housed in a box mounted on the pole to protect them from rain and dust. The light-trap was established on top of a hillock at Kariem Muriem. This hillock is located in the centre of the teak plantations in this 80
area. The trap was operated for a period of 16 months from 23 June 1993 to 15 October 1994. Daily collections of defoliator moths were made during the period 1993-94. The outbreaks, which occurred during this period, were mapped and the dates of start of these outbreaks were estimated as described in Chapter 3. During this period, all the outbreaks that occurred at Kariem Muriem were mapped and based on larval samples collected, the starting date of each infestation was determined as described in Chapter 3. It was examined whether moths were collected in the trap during the start of an outbreak so as to judge if it could be used as a monitoring device. 7.3. RESULTS The solar light trap developed was found satisfactory. Based on the prototype model described above, a more convenient portable model was designed with the following modifications: 1. The number ofsolar panels was reduced from 4 to 1. 2. The steel pole was reduced in size and was made collapsible. 3. The walk-in cage was replaced with a smaller cage. The trap catch during the 16-month period is given in Appendix Band depicted in Fig.7.2. along with the time of occurrence of outbreaks at Kariem Muriem. Distinct period of abundance of moths in the field can be identified. The period immediately after the establishment of the trap (June, 1993) was a time of high abundance of moths. There was a decline in trap-catch during August. There were further increases in the number of moths during the first weeks of September and October. Only very few moths were collected during November (2 moths) and December (1 moth). In 1994, no moths were collected during January, February and March. The first moth was collected on 2 April. Large number of moths were trapped during the moths of May, June and July beyond which no moths were collected until the end of the study in October. The correspondence between the trap catch and the initiation ofan outbreak is depicted in Table 7.1. 81
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SPATIAL DYNAMICS OF TEAK DEFOLIATOR
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CERTIFICATE This is to certify that
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Mr. Rajan James, Mr. A. Moosa, Mr.
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4.3.5. Correlation between outbreak
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CHAPTER I INTRODUCTION Insects are
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covering the entire plantations of
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Burma and recommended that providin
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In a two-year light trap study at J
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during 1983-94 and 1987-89 recorded
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area of 50 ha. A group of ten grids
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CHAPTER IV STUDIES ON THE SPATIAL D
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within these various spatially refe
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4.2.3. Correlation between outbreak
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4.3. 2. Outbreak pattern, 1993 The
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4.3.3. Outbreak pattern, 1994 Table
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_ 0 _ 1 0 2 _ 3 _ 4 _ 5
Page 37 and 38: _ 0 _ 1 0 1 _ 3
Page 39 and 40: Table 4.7. The relationship between
Page 41 and 42: Fig. 8. Location of first outbreak
Page 43 and 44: Table 4.9. Elevation and aspect oft
Page 45 and 46: aspect and outbreak frequency. The
Page 47 and 48: map. The methodology adopted for da
Page 49 and 50: The sixth outbreak occurred on 26 M
Page 51 and 52: explained as caused by progenies of
Page 55 and 56: Fig.5.3. Map ofNilambur teak planta
Page 61: Fig.5.9. Map ofNilambur teak planta
Page 67 and 68: Fig.5 .15. Map ofNilambur teak plan
Page 71 and 72: Fig.5.l9. Map ofNilambur teak plant
Page 73 and 74: Fig.5 .21. Map ofNilambur teak plan
Page 75: '------------------ ------- --- ---
Page 78 and 79: 6.2. METHODS In this study, post em
Page 80 and 81: was observed at around 06.15 h on t
Page 82 and 83: Two moths (one male and one female)
Page 84 and 85: Aggregations of the moths were pred
Page 86 and 87: CHAPTER VII DEVELOPMENT OF OUTBREAK
Page 91 and 92: Table 7.1. Correspondence between l
Page 93 and 94: foliage. If folds are detected, obs
Page 95 and 96: study has considerable bearing on t
Page 97 and 98: maximum of 13 ha (see Section 5.2,
Page 99 and 100: c) Variation in plant quality I ava
Page 102 and 103: away places. These populations seld
Page 104 and 105: Berryman, A. A. (1987) The theory a
Page 106: Nair, K. S. S., Mohanadas, K and Su
Page 109: APPENDIX A ALGORITHM: FOR COMPUTATI
Page 112 and 113: Date *No. of Incidence Local Date *
Page 115: Date "No. of Incidence local Date "
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Spatial dynamics of teak defoliator (Hyblaea puera Cramer) - Cochin ...

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