scholarly journals Study on the combined action of the entomopathogenic bacterium Bacillus thuringiensis subsp. kurstaki and the entomopathogenic nematode Heterorhabditis bacteriophora

2017 ◽  
Vol 23 (2) ◽  
pp. 74 ◽  
Author(s):  
I. Zampara ◽  
C. Zamparas ◽  
S. Mantzoukas ◽  
E. Karanastasi
Keyword(s):  
Bacillus Thuringiensis ◽  
Entomopathogenic Nematode ◽  
Heterorhabditis Bacteriophora ◽  
Post Treatment ◽  
Ephestia Kuehniella ◽  
Laboratory Conditions ◽  
Bacillus Thuringiensis Subsp ◽  
Lepidoptera Pyralidae ◽  
Combined Action ◽  
Bacterium Bacillus

The interaction between the entomopathogenic bacterium Bacillus thuringiensis subsp. Kurstaki and the entomopathogenic nematode Heterorhabditis bacteriophora (Heterorhabditidae) was examined against larvae of Ephestia kuehniella (Lepidoptera: Pyralidae) at 7, 14, 21 and 28 days post treatment, in laboratory conditions. Three different combinations of the aforementioned pathogens were tested on 4th instar larvae, namely 500ppm B. thuringiensis subsp. kurstaki (B.t.k.) and H. bacteriophora infective Juveniles (1000IJs/ml), 1500ppm B.t.k. and H. bacteriophora (1000IJs/ml) and 3000ppm B.t.k. and H. bacteriophora (1000IJs/ml). At 7, 14 and 21 days, the interaction between the pathogens was additive in two of the treatments and synergistic in one, whereas at 28 days, it was negative in two of the treatments and synergistic in one. Overall, the application of the lowest dose of B.t.k. (500ppm) in combination with H. bacteriophora (1000IJs/ml), turned out to be highly effective. The interaction between B. thuringiensis and H. bacteriophora is to be further examined.

scholarly journals Efficacy and speed of action of selected plant protection products on Lymantria dispar in laboratory conditions

2017 ◽  
Vol 18 ◽  
pp. 62 ◽  
Author(s):  
Z.D. Zartaloudis ◽  
M.D. Kalapanida ◽  
E.I. Navrozidis
Keyword(s):  
Bacillus Thuringiensis ◽  
Gypsy Moth ◽  
Lymantria Dispar ◽  
Plant Protection ◽  
Plant Protection Products ◽  
The Other ◽  
Larval Instars ◽  
Laboratory Conditions ◽  
Bacillus Thuringiensis Subsp

In this study some selected insecticides were evaluated for their effect on gypsy moth Lymantria dispar L., (Lepidoptera: Lymantriidae) under laboratory conditions. Diflubenzuron, methoxyfenozide, triflumuron, fenoxycarb, fenoxycarb + lufenuron, Bacillus thuringiensis 50% subsp. kurstaki + Bacillus thuringiensis 50% subsp. aizawai, Bacillus thuringiensis subsp. aizawai and spinosad were used in the recommended concentration, against the 1st, 2nd, 3rd and 4th larval instars of L. dispar. The effectiveness of the above insecticides as well as the speed of action (LTime50 and LTime90) expressed in days, were examined in detail. Spinosad and methoxyfenozide presents a relatively higher speed of action in relation to the other insecticides. LTime50 of spinosad and methoxyfenozide did not differ significantly among the first three larval instars and ranged from 0 to 0.61 and 1.13 to 1.74 days, respectively. Regarding IGRs, the mixture (fenoxycarb + lufenuron) and triflumuron were the most effective in relation to the other IGRs tested. Moreover, Bacillus thuringiensis toxins were effective only against the first two larval instars.

scholarly journals Comparative analysis of the individual protoxin components in P1 crystals of Bacillus thuringiensis subsp. kurstaki isolates NRD-12 and HD-1

1990 ◽  
Vol 269 (2) ◽  
pp. 507-512 ◽  
Author(s):  
L Masson ◽  
G Préfontaine ◽  
L Péloquin ◽  
P C K Lau ◽  
R Brousseau
Keyword(s):  
Bacillus Thuringiensis ◽  
Choristoneura Fumiferana ◽  
Insect Cell Line ◽  
Gene Products ◽  
Bacillus Thuringiensis Subsp ◽  
Independent Verification ◽  
Lepidopteran Larvae ◽  
Bacterium Bacillus ◽  
The Individual

Two commercially important strains (NRD-12 and HD-1) of the entomopathogenic bacterium Bacillus thuringiensis subsp. kurstaki each contain three genes of partially identical sequence coding for three classes of 130-135 kDa protoxins (termed the 4.5, 5.3 and 6.6 protoxins) that display toxicity towards various lepidopteran larvae. These gene products combine to form the intracellular bipyramidal P1 crystal. Each of the genes from both strains was cloned and expressed in Escherichia coli. Analysis of the cloned genes at the restriction-endonuclease level revealed no detectable differences among genes within a particular gene class. The composition of the P1 crystal from both strains was quantitatively analysed by CNBr cleavage of the purified P1 crystal, with the purified recombinant gene products as reference proteins. Independent verification of the presence of high 6.6-protoxin gene product in the P1 crystal was provided by a rapid in vitro lawn cell toxicity assay directed against a Choristoneura fumiferana (CF-1) insect cell line. The results indicate that, although all three gene products are represented within the P1 crystal of either NRD-12 or HD-1, only the contents of the 4.5 and 5.3 protoxins vary between the two crystals, whereas the 6.6 protoxin contents are similar and represent approximately one-third of the P1 crystal in either strain.

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