Laboratory and Field Evaluation of Bacillus Thuringiensis Berliner Products Against the Teak Defoliator, Hyblaea Puera Cramer

AbstractThe efficacy of seven chemical insecticides, five commercial preparations of Bacillus thuringiensis, and two preparations containing diatom dust were tested against the European skipper, Thymelicus lineola (Ochs.), under field conditions. Satisfactory control was obtained with carbaryl, carbofuran, methomyl, permethrin, trichlorfon, Dipel 45B(=Dipel SC), Dipel WP, Thuricide 26B, Thuricide HPC, and Novabac 3 while dimethoate, chlorpyrifos, and the diatom dusts afforded little or no foliage protection. While larval mortality occurred less rapidly when B. thuringiensis preparations were applied, their use is strongly recommended as they afford the same degree of foliage protection as chemical insecticides and diminish possible undesirable off-target effects.

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Field Evaluation of Transgenic Corn Containing a Bacillus thuringiensis Berliner Insecticidal Protein Gene Against Helicoverpa zea (Lepidoptera: Noctuidae)

Journal of Entomological Science ◽

10.18474/0749-8004-31.3.340 ◽

1996 ◽

Vol 31 (3) ◽

pp. 340-346 ◽

Cited By ~ 13

Author(s):

Steven R. Sims ◽

Jay C. Pershing ◽

Barbara J. Reich

Keyword(s):

Bacillus Thuringiensis ◽

Helicoverpa Zea ◽

Negative Relationship ◽

Field Evaluation ◽

Corn Earworm ◽

Insecticidal Protein ◽

Transgenic Corn ◽

First Instar ◽

Transgenic Lines ◽

Lepidoptera Noctuidae

Twelve independently transformed lines of transgenic corn (Zea mays L.) expressing the CryIA(b) insecticidal protein from Bacillus thuringiensis var. kurstaki were field tested to evaluate their resistance to the corn earworm, Helicoverpa zea (Boddie). Silks of the primary (=top) ears of transgenic [CryIA(b) positive] and isoline control plants [no CryIA(b) protein] were artificially infested with first-instar H. zea larvae and the length of ear penetration was measured after 19 d. Eight of the 12 lines had significantly less ear damage than their respective isoline controls; 3 transgenic lines reduced H. zea feeding damage by > 75% and stunted surviving H. zea larvae. Concentration of the CryIA(b) protein (μg/g fresh weight) in silks of the transgenic lines, determined using ELISA, ranged from 0.0 to 1.28 μg/g. Within transgenic lines, there was a weak (P < 0.06) negative relationship between the concentration of CryIA(b) protein in fresh silks and the length of H. zea ear penetration.

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Field Evaluation of Native B. thuringiensis Isolates Against Aphids (Aphis fabae)

Tribhuvan University Journal of Microbiology ◽

10.3126/tujm.v7i0.33854 ◽

2020 ◽

Vol 7 ◽

pp. 115-122

Author(s):

Ganga GC ◽

Charu Arjyal

Keyword(s):

Bacillus Thuringiensis ◽

Field Evaluation ◽

Staining Technique ◽

Selection Method ◽

Aphis Fabae ◽

Preliminary Screening ◽

Before And After ◽

Phaseolus Species ◽

Mortality Percentage ◽

Aphicidal Activity

Objectives: The purpose of this study was to evaluate the aphicidal activity of native Bacillus thuringiensis (Bt) strains. Methods: Soil samples of Provinces 2 and 3 of Nepal were collected randomly for isolation of Bt by acetate selection method. Bt were identified by observing insecticidal crystal proteins (ICPs) by Commassie Brilliant Blue (CBB) staining technique. Aphicidal activity of 12 B. thuringiensis isolates was evaluated by two processes. The preliminary screening was done by spraying the suspension containing the spore and ICPs mixture in Phaseolus species heavily infested with black aphids (Aphis fabae) in fi elds. The second process (selective bioassay) was done by counting the number of aphids (nymphs, instar, winged, wingless) before and after spraying 5ml of suspension containing the spore and ICPs mixture on the leaf or on the beans pods surface infested by Aphids. The mortality percentage of Aphids after treatment was calculated on the 4th day, by counting the live aphids and the result was recorded. Results: Preliminary screening for aphicidal activity revealed that 4 isolates ML5(1), CW1(1), SN2(1) and MP2(1) producing spherical crystal protein, showed 100% mortality against nymphs, instar, winged and wingless Aphids. Isolates were effective in controlling the Aphid (Aphis fabae) within 4 days and the part of the plant that was sprayed becomes free of Aphids. Selective bioassay of native isolate MP3(3) was most effective in killing 95.83% of aphids followed by CW2(1), 85.71%, ML5(1), 77.34%, SN3(1), 72.72%, CW1(1), 70.21%. Conclusion: This study revealed that indigenous Bacillus thuringiensis of Terai region of Nepal are effective in controlling Aphids.

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