Molecular identification of insecticide degradation by gut bacteria  isolated from Helicoverpa armigera of Cotton plants

The cotton bollworm Helicoverpa armigera occurs as a major pest in many economically important crops, including cotton, pigeon pea, chickpea, pea, cowpea, sunflower, tomato, sorghum, pearl millet and other crops. Intestinal microorganisms play important role in the degradation of diet components of insects. In order to know the role of gut bacteria in insecticide resistance five insecticides Chlorpyriphos (20% EC), Cypermethrin (25% EC), Malathion (50% EC), Quinalphos (25% EC), Triazophos (40% EC), were selected for the insecticide degradation studies. All the bacterial isolates from the gut of lab and field populations of H. armigera were identified using 16S rRNA gene-based identification and tested for their growth on minimal salt medium (MSM) along with the selected insecticides. A total of 11 bacterial isolates were tested and among them, isolate CL4 (Rhodococcus sp.) was found to grow on minimal salt medium (MSM) and with chlorpyriphos and isolate CL2 (Enterococcus casseliflavus) was able to grow in MSM with chloropyriphos (C22H19Cl2NO3) and malathion (C10H19O6PS2) and no growth was seen in MSM without insecticide (control). Gas Chromatography analysis of the positive bacterial isolate cultures in MSM showed that the isolate CL4 (Rhodococcus sp.) was able to utilize 43.9% of chlorpyriphos and isolate CL2 (E.casseliflavus) was able to utilize 26% of chlorpyriphos and 57.1% of malathion in MSM broth cultures with comparison with the respective control cultures. Findings of the current work suggested that gut bacteria in the field populations of H. armigera plays a role in insecticide resistance

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Mitigation of Insecticide Resistance in Helicoverpa armigera (Hubner) (Lepidoptera:Noctuidae) by Conjunctive Use of Trap Crops, Neem and Trichogramma chilonis Ishii in Cotton

International Journal of Zoological Research ◽

10.3923/ijzr.2005.53.58 ◽

2004 ◽

Vol 1 (1) ◽

pp. 53-58 ◽

Cited By ~ 7

Author(s):

P. Duraimurug ◽

A. Regupathy .

Keyword(s):

Insecticide Resistance ◽

Helicoverpa Armigera ◽

Conjunctive Use ◽

Trichogramma Chilonis ◽

Trap Crops ◽

Helicoverpa Armígera ◽

Helicoverpa Armigera Hubner

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Mitochondrial P-Glycoprotein ATPase Contributes to Insecticide Resistance in the Cotton Bollworm, Helicoverpa armigera (Noctuidae: Lepidoptera)

Cell Biochemistry and Biophysics ◽

10.1007/s12013-014-9969-5 ◽

2014 ◽

Vol 70 (1) ◽

pp. 651-660 ◽

Cited By ~ 5

Author(s):

S. Md Akbar ◽

Ravindra M. Aurade ◽

H. C. Sharma ◽

K. Sreeramulu

Keyword(s):

Insecticide Resistance ◽

Helicoverpa Armigera ◽

Cotton Bollworm ◽

P Glycoprotein ◽

Helicoverpa Armígera

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Section 1. The Australian insecticide resistance management strategy

Bulletin of entomological research supplement series ◽

10.1017/s1367426900000072 ◽

1993 ◽

Vol 1 ◽

pp. 1-4 ◽

Cited By ~ 90

Author(s):

Neil W. Forrester ◽

Matthew Cahill ◽

Lisa J. Bird ◽

Jacquelyn K. Layland

Keyword(s):

Insecticide Resistance ◽

Helicoverpa Armigera ◽

Pyrethroid Resistance ◽

Resistance Management ◽

Grain Legumes ◽

Pest Species ◽

Insecticide Resistance Management ◽

Eastern Australia ◽

Helicoverpa Armígera ◽

Chemical Groups

SummaryIn response to field pyrethroid failures against Helicoverpa armigera (Hübner) in early 1983, an insecticide resistance management (IRM) strategy was introduced for insect control in summer crops in eastern Australia. The aims of this strategy were to contain the pyrethroid resistance problem, to prevent re-selection of historical endosulfan resistance (both curative IRM) and to avoid any future problems with organophosphate/carbamate resistance (preventative IRM). An alternation strategy was adopted which was based on the rotation of unrelated chemical groups on a per generation basis, along with a strong recommendation for the use of ovicidal mixtures. These chemical countermeasures were then integrated with other non-chemical control methods (biological and cultural) into a workable integrated pest management programme. The restrictions were applied to all Helicoverpa armigera susceptible crops (including cereals, oilseeds, grain legumes, tomatoes, tobacco and cotton) and even to other co-incident pest species. From its inception, compliance with the voluntary strategy has been exceptional.

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Evaluation of cellulose degrading bacteria isolated from the gut-system of cotton bollworm, Helicoverpa armigera and their potential values in biomass conversion

PeerJ ◽

10.7717/peerj.11254 ◽

2021 ◽

Vol 9 ◽

pp. e11254

Author(s):

Mudasir A. Dar ◽

Afrin F. Shaikh ◽

Kiran D. Pawar ◽

Rongrong Xie ◽

Jianzhong Sun ◽

...

Keyword(s):

16S Rrna ◽

16S Rrna Gene ◽

Helicoverpa Armigera ◽

Cellulose Degradation ◽

Biomass Conversion ◽

Cotton Bollworm ◽

Symbiotic Bacteria ◽

Rrna Gene ◽

Degrading Bacteria ◽

Helicoverpa Armígera

Background Cotton bollworm, Helicoverpa armigera is a widely distributed, devastating pest of over 200 crop plants that mainly consist of some cellulosic materials. Despite its economic importance as a pest, little is known about the diversity and community structure of gut symbiotic bacteria potentially functioned in cellulose digestion in different gut-sections of H. armigera. In view of this lacuna, we attempted to evaluate and characterize cellulose-degrading bacteria (CDB) from foregut, midgut, and hindgut -regions of H. armigera by using a culture-dependent approach. Methodology The symbiotic bacteria were isolated from different gut-systems of H. armigera by enrichment techniques using Carboxymethyl cellulose sodium salt (CMC) as carbon source. The isolated bacteria were purified and subsequently screened for cellulose-degradation by plate-based method to display the zones of CMC clearance around the colonies. The identification and phylogeny of the gut-bacteria were reconstructed by using 16S rRNA gene sequencing. Different enzymes such as endoglucanase, exoglucanase, β-glucosidase, and xylanase were assayed to determine the cellulolytic repertoire of the isolated bacteria. Results The enrichment of CDB and subsequent plate based screening methods resulted in isolation of 71 bacteria among which 54% of the bacteria were obtained from foregut. Among the isolated bacteria, 25 isolates showed discernible cellulose-degradation potential on CMC-agar plates. The phylogenetic analysis based on 16S rRNA gene amplification and sequencing affiliated these cellulolytic bacteria to two major phyla viz., Firmicutes and Proteobacteria. The members of the genus Klebsiella accounted for 39.43% of the total isolated bacteria while 31% of the Bacillus strains were enriched from hindgut region. The principal component analysis (PCA) further suggested that the members of Bacillus and Klebsiella together dominated the foregut and hindgut regions as they accounted for 68% of the total CDB. The four potential isolates selected on the basis of plate-based activities were further evaluated for their lignocellulases production by using various agricultural wastes as substrates. The PCA of the enzyme activities demonstrated that potential isolates majorly secreted endoglucanase and xylanase enzymes. Among the agro-wastes, multivariate analysis validated wheat husk (WH) and sugarcane bagasse (SCB) as most favorable substrates for xylanase and endoglucanase productions respectively. The overall findings suggest that H. armigera harbors diverse bacterial communities in different gut-sections that could assist the host in digestion processes, which may potentially serve as a valuable reservoir of some unique symbionts applied for biomass conversion in biofuel industry.

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