Feeding Activity of Green Peach Aphid (Homoptera: Aphididae) on Transgenic Potato Expressing a Bacillus thuringiensis ssp. tenebrionis B-Endotoxin Gene

1994 ◽  
Vol 87 (3) ◽  
pp. 618-622 ◽  
Author(s):  
J.-N. Shieh ◽  
R. E. Berry ◽  
G. L. Reed ◽  
P. A. Rossignol
Keyword(s):  
Bacillus Thuringiensis ◽  
Green Peach Aphid ◽  
Feeding Activity ◽  
Transgenic Potato

scholarly journals Increased responsiveness in feeding behaviour of Caenorhabditis elegans after experimental coevolution with its microparasite Bacillus thuringiensis

2011 ◽  
Vol 8 (2) ◽  
pp. 234-236 ◽  
Author(s):  
Rebecca D. Schulte ◽  
Barbara Hasert ◽  
Carsten Makus ◽  
Nico K. Michiels ◽  
Hinrich Schulenburg
Keyword(s):  
Caenorhabditis Elegans ◽  
Bacillus Thuringiensis ◽  
Feeding Activity ◽  
Free Food ◽  
Immune System Activation ◽  
Evolution Experiment ◽  
Food Conditions ◽  
System Activation ◽  
Defence Strategy ◽  
Host Parasite

Immune responses, either constitutive or induced, are costly. An alternative defence strategy may be based on behavioural responses. For example, avoidance behaviour reduces contact with pathogens and thus the risk of infection as well as the requirement of immune system activation. Similarly, if pathogens are taken up orally, preferential feeding of pathogen-free food may be advantageous. Behavioural defences have been found in many animals, including the nematode Caenorhabditis elegans . We here tested nematodes from a laboratory based evolution experiment which had either coevolved with their microparasite Bacillus thuringiensis (BT) or evolved under control conditions. After 48 generations, coevolved populations were more sensitive to food conditions: in comparison with the controls, they reduced feeding activity in the presence of pathogenic BT strains while at the same time increasing it in the presence of non-pathogenic strains. We conclude that host–parasite coevolution can drive changes in the behavioural responsiveness to bacterial microbes, potentially leading to an increased defence against pathogens.

SUSCEPTIBILITY OF SOME FOREST INSECTS TO MIXTURES OF COMMERCIAL BACILLUS THURINGIENSIS AND CHEMICAL INSECTICIDES, AND SENSITIVITY OF THE PATHOGEN TO THE INSECTICIDES

1972 ◽  
Vol 104 (9) ◽  
pp. 1419-1425 ◽  
Author(s):  
Oswald N. Morris
Keyword(s):  
Bacillus Thuringiensis ◽  
Feeding Activity ◽  
Low Doses ◽  
Chemical Insecticide ◽  
Drastic Reduction ◽  
Hyphantria Cunea ◽  
Test Species ◽  
Relative Susceptibility ◽  
Forest Insects ◽  
Low Concentrations

AbstractExperiments were designed to determine the effects of low doses of some insecticides on the viability and physiological characteristics of commercial Bacillus thuringiensis (Berliner) as a prelude to studies on the susceptibility of lepidopterous forest defoliators to mixtures of bacteria and insecticides.The results show that the insecticides tested had no effect on viability or physiological integrity of the bacteria.Bacteria–insecticide combination effects varied from strongly antagonistic to strongly supplemental depending on insecticide or Thuricide® formulations and concentrations and on the relative susceptibility of the test species to either agent applied separately. Pyrethrum at 10−3 was highly potentiating to BT at 10−1 against third instar Halisidota argentata. Among Hyphantria cunea, a supplemental effect always resulted from combining Thuricide® at 10−2 with low concentrations of malathion, phosphamidon, or pyrethrum.There was generally a drastic reduction in feeding activity among BT-treated insects and a further reduction among BT-chemical-insecticide-treated ones compared with controls.

scholarly journals Effects ofmti-2Transgenic Potato Plants on the AphidMyzus persicae(Sternorrhyncha: Aphididae)

2010 ◽  
Vol 2010 ◽  
pp. 1-7 ◽  
Author(s):  
Julien Saguez ◽  
Anas Cherqui ◽  
Salima Lehraiki ◽  
Charles Vincent ◽  
Antony Beaujean ◽  
...  
Keyword(s):  
Doubling Time ◽  
Green Peach Aphid ◽  
Intrinsic Rate ◽  
Transgenic Potato ◽  
Natural Increase ◽  
Insecticidal Effect ◽  
Potato Plants ◽  
Prereproductive Period ◽  
High Level ◽  
Almost All

Overexpressed in transgenic plants, protease inhibitors showed insecticidal effects against several insect taxa. We transformed potato internodes with the mustard trypsin inhibitormti-2gene. Among the 35 independent transgenic potato lines obtained viaAgrobacterium tumefascienstransformation, four (DM6, DM7, DM11, and DM19) were selected for their high level of MTI-2 (at least to 30% of trypsin activity inhibition). Feeding assays were carried out to evaluate their effects on the green-peach aphid,Myzus persicae(Sternorrhyncha: Aphididae). Prereproductive period, nymphal mortality, adult fecundity, and doubling time ofM. persicaepopulations were monitored on nontransformed potato plants (NT) and the four selected DM lines. Compared to NT plants, DM19 did not induce any effect onM. persicae. In contrast, DM7 and DM11 increased nymphal survival by approximately 20%. DM6 and DM11 lines slightly enhancedM. persicaedaily fecundity and intrinsic rate of natural increase, leading to a reduction of the doubling time of the populations by 1 day. DM6 did not impact nymphal mortality, whereas with the DM11 almost all the nymphs survived. Potato plants transformed with the mti-2 gene variably affected the life history ofM. persicaebut did not show any insecticidal effect on the aphid.

CHANGES IN SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA (LEPIDOPTERA: TORTRICIDAE), BIOMASS IN STANDS TREATED WITH COMMERCIAL BACILLUS THURINGIENSIS VAR. KURSTAKI

1983 ◽  
Vol 115 (4) ◽  
pp. 431-434
Author(s):  
O. N. Morris ◽  
A. Moore
Keyword(s):  
Bacillus Thuringiensis ◽  
Choristoneura Fumiferana ◽  
Feeding Activity ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
Term Effect ◽  
Balsam Fir ◽  
Long Term Effect ◽  
Biomass Reduction

AbstractLarval biomass of the spruce bud worm, Choristoneura fumiferana (Clem.), in balsam fir, Abies balsamea L., stands was significantly reduced following aerial applications of commercial Bacillus thuringiensis (B.t.) (Thuricide 16B®, 24B and 32BX and Dipel 85®). Treatment with Dipel vehicle (Dipel 88® without B.t.) did not affect larval biomass. Biomass reduction following the Thuricide treatment was directly related to feeding activity. These findings support published observations on the long-term effect of B.t. on budworm populations.

scholarly journals Additive and synergistic interactions of entomopathogenic fungi with Bacillus thuringiensis for the control of the European grapevine moth Lobesia botrana (Denis and Schiffermüller) (Lepidoptera: Tortricidae)

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Evangelos Beris ◽  
Elias Korkas
Keyword(s):  
Bacillus Thuringiensis ◽  
Entomopathogenic Fungi ◽  
Combination Treatment ◽  
Abiotic Factors ◽  
Feeding Activity ◽  
Larval Mortality ◽  
Lobesia Botrana ◽  
European Grapevine Moth ◽  
Additive Action ◽  
Grapevine Moth

Abstract Background The European grapevine moth, Lobesia botrana (Denis and Schiffermüller) (Lepidoptera: Tortricidae) is currently the most damaging pest in many viticultural regions across the Mediterranean basin and elsewhere. Its feeding activity also enhances the development of secondary infections by Botrytis cinerea - and other fungi - to wine grapes. The gram-positive bacterium Bacillus thuringiensis (Bt) has been reported to partially control larval populations of L. botrana, while it requires to be digested by the insect to cause infection. Entomopathogenic fungi (EPF) are possibly capable of acting synergistically with Bt to increase its efficacy against insect pests. Results The hypothesis of synergy or antagonism between Bt and EPF for the control of L. botrana was tested in two bioassays: A) Insects fed on Bt diet and subsequently some groups were sprayed by conidia of Beauveria bassiana or Paecilomyces fumosoroseus, and B) Grapes were sprayed by Bt, or B. bassiana, or combination of the two, and then untreated insects were placed to feed on the grapes. In both bioassays, combination treatments performed better than single treatments, indicating additive action or synergy. The Bt and B. bassiana combination treatment (Bt diet for 30 h and then sprayed with conidia of B. bassiana) resulted in 91% larval mortality while the single Bt and B. bassiana treatments caused 28% and 34% mortality respectively. Such results indicated synergism. Combination treatment on grapes also caused significantly higher mortality on L. botrana larvae, compared to single treatments. The median lethal time (LT50) was estimated as 8.43 days for the single Bt treatment, 7.87 days for the single B. bassiana treatment and 6.3 days for the combination Bt + B. bassiana treatment. Conclusions Absence of antagonism as well as additive action or synergy were indicated by the results. Larval populations of the pest can be effectively controlled by using microbial biocontrol agents. Further research is needed to investigate the biotic and abiotic factors that affect interactions between insect hosts and entomopathogenic organisms. However, the entomopathogens used in the present study showed remarkable action and may be included parallelly in control strategies against vineyard pests.

SUSCEPTIBILITY OF THE BERTHA ARMYWORM, MAMESTRA CONFIGURATA (LEPIDOPTERA: NOCTUIDAE), TO COMMERCIAL FORMULATIONS OF BACILLUS THURMGIENSIS VAR. KURSTAKI

1986 ◽  
Vol 118 (5) ◽  
pp. 473-478 ◽  
Author(s):  
O.N. Morris
Keyword(s):  
Weight Gain ◽  
Brassica Napus ◽  
Bacillus Thuringiensis ◽  
Choristoneura Fumiferana ◽  
Feeding Activity ◽  
Adult Emergence ◽  
Mamestra Configurata ◽  
Lethal Time ◽  
Lepidoptera Noctuidae ◽  
Bertha Armyworm

AbstractCommercial Bacillus thuringiensis var. kurstaki (B.t.k.) (Dipel 132® and Thuricide 48 LV®) were bioassayed at 20 and 25°C against 3rd- (L3), 4th- (L4), 5th- (L5), and 6th- (L6) instar larvae of the bertha armyworm, Mamestra configurata Walker, on greenhouse-grown canola, Brassica napus L. cv. Westar. The L4 was the most susceptible stage to B.t.k. but it was much less susceptible than the spruce budworm, Choristoneura fumiferana (Clem.), a species against which this bacterium is currently used. The lethal time of B.t.k. to the larvae was inversely related to dosage applied. Younger instars (L3 to L4) were more sensitive to Dipel than older instars (L5 to L6) at 20°C but the reverse was true for Thuricide-treated larvae. All B.t.k. treatments reduced weight gain and frass deposition (by inference feeding activity) compared with untreated controls. The LC50 concentration of B.t.k. for larvae reduced survival to adult emergence by 87–100%.

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