ISOLATION AND CHARACTERIZATION OF ENTOMOPATHOGENIC ...

More documents

Recommendations

Info

occurred in a 5 per cent emulsion of the oil in water even after homogenization. Conidia of Metarhizium flavoviride in sprays of oil and oil in water emulsion survived longer on foliage than those in water, which they presumed to be because, the oil component gave greater protection from environmental stresses (Jenkins and Thomas, 1996). Nutrients such as cereal flour can be formulated as the carrier in a dust on wettable powder. The best known example is Verticillium lecanii in the products Vertalec and Mycotal, used against aphid and whitefly intermittently since 1980 (Burges, 1981; Ravensberg et al., 1990). Flour based V. lecanii products gave better pest control than sprays of spores alone (Kanagaratnam et al., 1982). Very few oils have been tested in the presence of dried silica gel. With M. flavoviride, there was no consistent difference between diesel oil, odourless kerosene, shellsol k, aviation fuel, groundnut oil or soy oil. Anti oxidants improved conidial survival in groundnut oil and in soy oil by 23-26 per cent (Moore et al., 1996). For conidial storage, mineral oils collectively, were similar to vegetable oils, some of which have the disadvantages of rancidity and solidification over long periods at high ambient temperature. Kerosene was found to be slightly better than groundnut (Stathers et al., 1993). Certain fatty acids from rancid oil inhibit germination of M. flavoviride conidia (Barnes and Moore, 1997). Hayler (1993) reported that the addition of rape seed oil to the fungus, V. lecanii increased efficiency upto 90 per cent when tested on. A. gossypii and Frankliniella occidentalis on cucumber in a greenhouse experiment. 2.7 EFFICACY <strong>OF</strong> <strong>ENTOMOPATHOGENIC</strong> FUNGI AGAINST INSECTS 2.7.1 Efficacy of Verticillium lecanii (Zimm.) against aphids Verticillium lecanii (Zimm.) (Monilales:Moniliaceae), an entomopathogenic fungus found world wide, has been used successfully as biological control agent against various species of aphids for number of years (Hall, 1982). The suspension of Verticillium lecanii with concentration of 16 x 10 6 spores/ml, when used against coffee green bug, Coccus viridis (Green) in Tamil Nadu, gave 16.6 per cent morality. The sprays containing surface active agents like Teepol, Triton x 100 at 0.03 per cent or glycerol at 0.1-0.3 per cent gave 48.9, 79.9 and 22.4 to 31.0 per cent mortality, respectively. Khalil et al. (1983) in Czechoslovakia, while studying on V. lecanii, found that when the fungus was applied at concentration of 10 8 spores/ml in sprays to plants in glasshouse was highly effective against the aphid species, Aphis fabae on sugar beet and Myzus persicae on cucumber. The effect of a range of humidities on the transmission and sporulation of a commercial preparation (Vertalec) of V. lecanii was investigated in greenhouse at 20°C on capsicum against aphid M. persicae by Milner and Lutton (1986). They found that at least 36 hours is required for infection at 100 per cent relative humidity. After 96 hours of spraying, 94.5 per cent of M. persicae were infected. Evaluation of the entomopathogen V. lecanii in the control of the aphid, M. persicae on chrysanthemum was conducted by Hincapie et al. (1990). Three strains of the fungus viz., VL-A, isolate from M. persicae, VL-GC isolated from Erinnyis ello and VL-MR from trialeurodes vaporariorum Weshw were used. VL-A caused 100 per cent mortality compared to 37.5 per cent for VL-GC and 30 per cent for Vl-MR. Three concentrations of VL-A was evaluated (1x10 4 , 1x10 6 , 1x10 8 ) and the mortality increased from 39.5 to 100 per cent.
Pathogencity of various strains/isolates of V. lecanii has been well established against various aphid species viz., A. fabae, D. noxia (Fegan et al., 1992), Sitobian avenae F. (Fegan et al., 1993; Miranpuri and Khachatourians, 1995), R. padi and M. persicae (Gardner et al., 1998). Khalil et al. (1990) studied the effectiveness of V. lecanii against the aphid M. persicae in laboratory, on one year old potted peach plants. The fungus was effective at concentrations of 10, 10 5 and 10 7 spores/ml with number of aphids alive/cm leaf area after 25 days being 0.68, 0.61 and 0.57, respectively, compared with the control value of 1.91. Masuda and Kikuchi (1992) investigated pathogenicity of V. lecanii isolates on aphids, A. gossypii, M. persicae and whitefly T. vaporariorum. Both isolates MGV118 and MGV 145 were pathogenic to larvae and adults of T. vaporariorum than MGV 145. MGV 145 was stronger than that of MGV118 on the apterous adults of A. gossypi and adults of M. persicae. The mortalities caused by the two isolates were almost the same (96-100%) at higher concentration (10 7 and 10 8 conidia/ml). Two years of laboratory and field assessments using entomopathogenic fungus, V. lecanii against Saskatoon berry leaf aphid, Acryrthosiphon macrosiphum (Wilson) showed 70 per cent aphid kill, three days after treatment. After five days of treatments, it showed 90 to 100 per cent aphid kill, three days after treatments. After five days of treatment, it showed 90 to 100 per cent aphid mortality as compared to 35 per cent in control groups. Field tests using two application of V. lecanii showed a significant decline in aphid population as compared to that on the water treated plants (Miranpuri and Khachatourians, 1995). 2.7.2 Effect of V. lecanii against whitefly On the spiraling whitefly, A. disperses, no research work on the use of microbial pesticides has been carried out so far. Quinden (1984) tested the mycotal formulation of the fungus Verticillium lecanii applied to tomato crop against greenhouse whitefly, Trialeurodes Vaporariorum at the rate of 5 x 10 11 spores/ha which gave significant control of the aleyrodid only 16 days after application. Suklova (1989) reported that V. lecanii + boverin (Beauveria bassiana) gave 98 per cent control of whitefly. Optimum condition for these fungi was 80-90 per cent relative humidity and a temperature of 26-28°C. Meade and Bruce (1991) reported on the mortality of various instars of B. tabaci and T. vaporariorum resulting from exposure to V. lecanii. The mortality of nymphs of all three instars of both species due to fungal infection was significantly higher than that in other treatments. According to Nier et al. (1993), the pathogencity of V. lecanii against nymphs of T. vaporariorum and B. tabaci at the concentration of 3.2 x 10 6 conidia per ml gave 91 and 100 per cent mortality, respectively, but a suspension containing 1 x 10 7 conidia per ml resulted in infection rate of 78 per cent. B. tabaci was found more susceptible than T. vaporariorum. Application of the fungus, Paecilomyces persimilis (Wize) followed by three introductions of two Encarsia formosa per plant and treatment of Ashersonia species gave good control as did the application of V. lecanii against B. tabaci (Landa, 1984). Field trials were carried out in Tamil Nadu by Jayaraj (1989) to determine the effectiveness of V. lecanii in controlling the coffee scale Coccus viridis. The fungus caused 73.1 per cent mortality of the pest when applied at 1.6 x 10 6 spores per ml twice at an interval of two weeks. The maximum mortality of 97.6 per cent was obtained when the surfactant, tween 20 was added to the spore suspension. High volume spray was more effective than low volume. The addition of 0.1 per cent glycerol enhanced the effectiveness of the fungus.
Page 1 and 2: ISOLATION AND CHARACTERIZATION OF E
Page 3 and 4: Chapter No. I INTRODUCTION C O N T
Page 5 and 6: Contd….. Table No. Title 14. Spor
Page 7 and 8: Contd….. Table No. Title 39. Per
Page 9 and 10: Plate No. LIST OF PLATES Title 1. M
Page 11 and 12: I.INTRODUCTION The increased use of
Page 13 and 14: II. REVIEW OF LITERATURE The variou
Page 15 and 16: The entomopathogenic fungi so far i
Page 17 and 18: Table 1. Contd….. Sl. No. Insect
Page 19 and 20: Milner et al. (2002) studied the ef
Page 21: 25°C for sporulation and biomass p
Page 25 and 26: Gopalkrishnan and Mohan (2000) test
Page 27 and 28: necessary serial dilutions under ph
Page 29 and 30: Sl. No. Table 2. Details of differe
Page 31 and 32: 3.9 EVALUATION OF DIFFERENT FORMULA
Page 33 and 34: Fig. 1. Mycopathogens of insect pes
Page 35 and 36: Table 5. Contd….. Month/s visited
Page 37 and 38: Table 5. Contd….. Month/s visited
Page 39 and 40: Table 5. Contd….. Mycosis noticed
Page 41 and 42: Totally eight isolates of N. rileyi
Page 43 and 44: Metarhizium anisopliae Vertucillium
Page 45 and 46: Ma 1 (Dharwad) Ma2 (Dharwad) Ma 3 (
Page 47 and 48: Table 8. Mortality caused by the is
Page 49 and 50: Helicoverpa armigera Dimond Black M
Page 51 and 52: Plate 5. The moratality of Hlelicov
Page 53 and 54: Table 11. Total biomass production
Page 55 and 56: Table 12. Total biomass production
Page 57 and 58: Table 14. Sporulation of Metarhiziu
Page 59 and 60: Mean spore yield x 10 8 /g 25 20 15
Page 61 and 62: Among the non-grain substrates, the
Page 63 and 64: Mean spore yield x 10 4 /g 35 30 25
Page 65 and 66: Sl. No. Table 19. Effect of fungici
Page 67 and 68: Per cent inhibition 100 90 80 70 60
Page 69 and 70: Sl. No. Table 21. Effect of insecti
Page 71 and 72: Out of nine insecticides, endosulfa
Page 73 and 74:
Sl. No. Table 23. Effect of weedici
Page 75 and 76:
Days after storage Table 25. Persis
Page 77 and 78:
Table 26. Survival of Metarhizium a
Page 79 and 80:
Table 28. Survival of Metarhizium a
Page 81 and 82:
Sl. No. Table 29. Survival of Metar
Page 83 and 84:
Sl. No. Table 30. Survival of Metar
Page 85 and 86:
Per cent germination 90 80 70 60 50
Page 87 and 88:
Sl. No. Table 33. Survival of Verti
Page 89 and 90:
Page 91 and 92:
Page 93 and 94:
4.9 PATHOGENICITY OF Verticillium l
Page 95 and 96:
Sl. No. Table 39. Per cent mortalit
Page 97 and 98:
Culture grown on rice grains Harves
Page 99 and 100:
Tr. No. Table 41. Per cent reductio
Page 101 and 102:
Tr. No. Table 43. Per cent reductio
Page 103 and 104:
The fungal spray at higher dosage (
Page 105 and 106:
Table 46. Effect of wild types and
Page 107 and 108:
The hyphal and conidial characters
Page 109 and 110:
In an earlier experiment, bagasse w
Page 111 and 112:
M. anisopliae exhibited rapid reduc
Page 113 and 114:
higher mortality of aphids. The com
Page 115 and 116:
14. Oil formulations proved better
Page 117 and 118:
CHARNLEY, A.K. AND ST. LEGER, R.J.,
Page 119 and 120:
IGNOFFO, C.M., MARSTON, N.L., HOSTE
Page 121 and 122:
MULLER, E.J., 2000, Control of the
Page 123 and 124:
ST LEGER, R.J., BUTT, T.M., STAPLES
Page 125 and 126:
APPENDIX I Mean monthly weather dat
Page 127 and 128:
Maharashtra Association for the Cul
Page 129:
ISOLATION AND CHARACTERIZATION OF E
show all

ISOLATION AND CHARACTERIZATION OF ENTOMOPATHOGENIC ...

Create successful ePaper yourself

Delete template?

Save as template?