Computation of economic threshold and economic injury level of Helicoverpa armigera (Hubner) in chickpea

2021 ◽  
Vol 45 (4) ◽  
pp. 696-701
Author(s):  
Ravinder Singh ◽  
G.K. Taggar ◽  
Akanksha Singla ◽  
P.K. Chhuneja
Keyword(s):  
Helicoverpa Armigera ◽  
Economic Injury Level ◽  
Economic Threshold ◽  
Economic Injury ◽  
Helicoverpa Armígera ◽  
Helicoverpa Armigera Hubner

scholarly journals Economic injury level of Helicoverpa armigera on bean Phaseolus vulgaris L. seedlings

2020 ◽  
Vol 18 (3) ◽  
pp. 308
Author(s):  
Fernando Belezini Vinha ◽  
Lucas André Genari ◽  
Mauricio Bianchi Masson ◽  
Alexandre De Sene Pinto
Keyword(s):  
Phaseolus Vulgaris ◽  
Helicoverpa Armigera ◽  
Economic Injury Level ◽  
Phaseolus Vulgaris L ◽  
Economic Injury ◽  
Helicoverpa Armígera ◽  
Lepidoptera Noctuidae ◽  
Helicoverpa Armigera Hubner

A lagarta Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) chegou ao Brasil em 2012 e vem causando prejuízos severos aos agricultores, especialmente nas culturas do algodão, feijão, milho, soja e tomate nas regiões Norte, Nordeste e Centro-Oeste. Pouco se conhece sobre seus danos às culturas no país e o feijoeiro é uma das culturas menos estudadas dentre as citadas. Portanto, esse trabalho objetivou-se avaliar o nível de dano causado pela lagarta H. armigera de 3º ínstar em plântulas de feijão cv. BRS-Estilo. O ensaio foi semeado em 10/04/2014, em Ribeirão Preto, SP, com espaçamento de 0,5 m e 12 plantas por metro. Em um delineamento em blocos casualizados, as infestações (18/04) de 0 (testemunha), 0,1, 0,2, 0,5 e 1 lagarta por planta foram repetidas quatro vezes, em parcelas de 0,5 m2 cercadas por barreias de PVC de 20 cm de altura e com bordadura de 1 m. Após 1, 3, 7 e 14 dias após a infestação foi avaliada a porcentagem de desfolha. A porcentagem média de desfolha foi proporcional à densidade de lagartas. O nível de dano de lagartas de 3º ínstar de H. armigera é de 1,4 lagartas por planta e, dessa forma, o nível de controle deve ser de 0,7 lagartas por planta de feijoeiro.

Determination of an Economic Injury Level for Old World Bollworm (Lepidoptera: Noctuidae) in Processing Tomato in Brazil

2020 ◽  
Vol 113 (4) ◽  
pp. 1881-1887
Author(s):  
Nayara C M Sousa ◽  
Miguel Michereff Filho ◽  
Paloma A Silva ◽  
Jorge B Torres
Keyword(s):  
Helicoverpa Armigera ◽  
Control Program ◽  
Yield Reduction ◽  
Economic Injury Level ◽  
Field Cage ◽  
Tomato Plants ◽  
Processing Tomato ◽  
Economic Injury ◽  
Helicoverpa Armígera ◽  
Lepidoptera Noctuidae

Abstract Tomato plants host various herbivores, including the Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae), recently introduced into South and Central America. It is a harmful pest for tomato crops, damaging mainly the flowers and fruits. The assessment of losses and the establishment of economic injury level (EIL) and economic threshold (ET) are core steps toward establishing a control program. We determined losses caused by H. armigera on processing tomato and estimated EIL/ET values. Trials were run during two growing seasons using tomato plants caged in the field. The field cage experiment consisted of six densities of H. armigera second instar larvae (0, 1, 3, 6, 12, and 24 larvae per row meter) at two infestations periods spaced 15 d apart with the first infestation done 90 d after transplanting. The larvae were placed individually on the third upper fully developed leaf. The number of healthy and damaged fruits, size, and weight of the fruits were measured. Yield losses as a function of infestation of 1–24 larvae per row meter ranged from 4 to 34% and resulted in a yield reduction of 1.22–12.77 kg per row meter. The EIL ranged from 1.41 to 1.72 and from 2.11 to 2.58 larvae per row meter of plants in 2017 and 2018 cropping seasons, respectively. Helicoverpa armigera causes significant reduction of tomato yield. These EIL values will enable better control decision-making in processing tomato.

scholarly journals Comparative TMT Proteomic Analysis Unveils Unique Insights into Helicoverpa armigera (Hübner) Resistance in Cajanus scarabaeoides (L.) Thouars

2021 ◽  
Vol 22 (11) ◽  
pp. 5941
Author(s):  
Abigail Ngugi-Dawit ◽  
Isaac Njaci ◽  
Thomas J.V. Higgins ◽  
Brett Williams ◽  
Sita R. Ghimire ◽  
...  
Keyword(s):  
Host Plant ◽  
Helicoverpa Armigera ◽  
Plant Resistance ◽  
Host Plant Resistance ◽  
Proteomic Analysis ◽  
Artificial Diet ◽  
Growth Stages ◽  
Genetic Base ◽  
Helicoverpa Armígera ◽  
Helicoverpa Armigera Hubner

Pigeonpea [Cajanus cajan (L.) Millspaugh] is an economically important legume playing a crucial role in the semi-arid tropics. Pigeonpea is susceptible to Helicoverpa armigera (Hübner), which causes devastating yield losses. This pest is developing resistance to many commercially available insecticides. Therefore, crop wild relatives of pigeonpea, are being considered as potential sources of genes to expand the genetic base of cultivated pigeonpea to improve traits such as host plant resistance to pests and pathogens. Quantitative proteomic analysis was conducted using the tandem mass tag platform to identify differentially abundant proteins between IBS 3471 and ICPL 87 tolerant accession and susceptible variety to H. armigera, respectively. Leaf proteome were analysed at the vegetative and flowering/podding growth stages. H. armigera tolerance in IBS 3471 appeared to be related to enhanced defence responses, such as changes in secondary metabolite precursors, antioxidants, and the phenylpropanoid pathway. The development of larvae fed on an artificial diet with IBS 3471 lyophilised leaves showed similar inhibition with those fed on an artificial diet with quercetin concentrations with 32 mg/25 g of artificial diet. DAB staining (3,3’-diaminobenzidine) revealed a rapid accumulation of reactive oxygen species in IBS 3471. We conclude that IBS 3471 is an ideal candidate for improving the genetic base of cultivated pigeonpea, including traits for host plant resistance.

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