Helicoverpa Armigera Research Articles

UJI BEBERAPA KONSENTRASI EKSTRAK TEPUNG AKAR TUBA (Derris elliptica Benth) UNTUK MENGENDALIKAN HAMA PENGGEREK TONGKOL JAGUNG Helicoverpa armigera Hubn

Pests that attack the corn crop are corn cobs borer (Helicoverpa armigera Hubner). Pest control can be done using tubal root vegetable insecticide (Derris elliptica benth.) This study aims to obtain the best concentration of tuba root powder extract for controlling the corncob borer pests Helicoverpa Armigera H. Research was carried out at the Plant Pest Laboratory of the Faculty of Agriculture, University of Riau. This study used a completely randomized design (CRD) with 6 treatments and 4 replications. The treatments were given several concentrations of tuba root powder extract, namely 0 gr.l-1 water, 20 gr.l-1 water, 40 gr.l-1 water, 60 gr.l-1 water, 80 gr.l-1 water and 100 gr.l-1 water. The parameters observed were initial death, lethal time of 50, lethal concentration of 50 and 95, daily mortality, and total mortality. Daily mortality data obtained from the results were analyzed descriptively and displayed in graphical form, data lethal concentration (LC50 and LC95) was used probit analysis using the POLO-PC program, while other data such as initial death, total mortality, and lethal time (LT50) were statistically analyzed using variance. Data from analysis of variance will be continued using the smallest significant difference (LSD) test at the 5% confident level. Application of concentration for tubal root extract 100 g-1 water was the best concentration to control larvae H. Armigera with an initial time of death 26.50 hours, LT50 67.50 hours, highest daily mortality on the fourth day by 40% and total larval mortality by 87.5%.

Cajanus platycarpus Flavonoid 3'5' Hydroxylase_2 (CpF3'5'H_2) Confers Resistance to Helicoverpa armigera by Modulating Total Polyphenols and Flavonoids in Transgenic Tobacco.

Pod borer Helicoverpa armigera, a polyphagus herbivorous pest, tremendously incurs crop damage in economically important crops. This necessitates the identification and utility of novel genes for the control of the herbivore. The present study deals with the characterization of a flavonoid 3'5' hydroxylase_2 (F3'5'H_2) from a pigeonpea wild relative Cajanus platycarpus, possessing a robust chemical resistance response to H. armigera. Though F3'5'H_2 displayed a dynamic expression pattern in both C. platycarpus (Cp) and the cultivated pigeonpea, Cajanus cajan (Cc) during continued herbivory, CpF3'5'H_2 showed a 4.6-fold increase vis a vis 3-fold in CcF3'5'H_2. Despite similar gene copy numbers in the two Cajanus spp., interesting genic and promoter sequence changes highlighted the stress responsiveness of CpF3'5'H_2. The relevance of CpF3'5'H_2 in H. armigera resistance was further validated in CpF3'5'H_2-overexpressed transgenic tobacco based on reduced leaf damage and increased larval mortality through an in vitro bioassay. As exciting maiden clues, CpF3'5'H_2 deterred herbivory in transgenic tobacco by increasing total flavonoids, polyphenols and reactive oxygen species (ROS) scavenging capacity. To the best of our knowledge, this is a maiden attempt ascertaining the role of F3'5'H_2 gene in the management of H. armigera. These interesting leads suggest the potential of this pivotal branch-point gene in biotic stress management programs.

Comparison of insecticide toxicity in adult and larval stages of Spodoptera frugiperda (J.E. Smith) and Helicoverpa armigera (Hünber) (Lepidoptera: Noctuidae)

Larvae of Helicoverpa armigera and Spodoptera frugiperda are important pests of agricultural commodities and while chemical control targeting larvae of these pest species is widely adopted, suppression of populations by bisexual attract-and-kill strategies which target adults also have potential applications in management. This study investigated the relative toxicity of insecticide groups registered as mixing partners for attract-and-kill agents in Australia. Contact and ingestion toxicity in adult and larval stages of H. armigera and S. frugiperda was tested by administering methomyl and spinosyn insecticides topically and orally in laboratory bioassays. Methomyl was generally the least toxic insecticide and larvae of both species were less sensitive to methomyl than adults. Adult mortality induced by methomyl was stable from 24 to 72 h after treatment in S. frugiperda whereas mortality of adult H. armigera increased from 24 to 72 h. Spinosyns were slower acting in both H. armigera and S. frugiperda with increases in adult mortality from 24 to 72 h after treatment. Spinetoram was the most toxic insecticide on adults and larvae both H. armigera and S. frugiperda with higher insecticidal activity on larvae compared to adults of both species. Spinosad was also more toxic on larvae of S. frugiperda compared to adults. This was in contrast to H. armigera larvae which were less sensitive to spinosad than their adult counterparts. A between-species comparison of insecticide toxicity showed larvae of both species were equally sensitive to spinosyns while adults of H. armigera were more sensitive to all three insecticides than adults of S. frugiperda. These results suggest that spinosyns could be effective options for strategies that target adult life stages of both H. armigera and S. frugiperda.

Bio-efficacy of newer insecticides against gram pod borer Helicoverpa armigera (Hubner) on chickpea (Cicer arietinum L.)

Six insecticides namely Emamectin benzoat 5% SG, Spinetoram 11.7% SC, Spinosad 45.0% SC, Flubendiamide 48 % SC, Chlorantraniliprole 18.5% SC, Novaluron 10% EC were evaluated against Gram Pod Borer (Helicoverpa armigera Hubner) larvae. The Gram Pod Borer (GPB) larval population was counted on five randomly selected plants, 24 hrs. before spray and at 3, 7 and 10 days after spray. The two-year experiment was conducted during Rabi 2018-19 and 2019-20 at the Rehti Farm of school of agriculture, Mhow, experimental field of Department of Entomology, BRAUSS, (MP). All the Chemical insecticides significantly reduced the GPB larval population. The Pooled GPB population varied from 2.23 to 2.57 larvae/ plant during Rabi season at one day prior to first spray. The population was significant lower with, Chlorantraniliprole 18.5% SC, followed by Spinetoram 11.7% SC, Spinosad 45.0% SC, Flubendiamide 48 % SC and Emamectin benzoat 5% SG these five insectiicdes are showing best management effects on the GPB larvae and pod damage .Novaluron 10% EC gave are least effective on larval population and pod damage. The highest chickpea grain yield (19.13q/ha) was obtained with Chlorantraniliprole 18.5% SC.

Evaluation the efficacy of bio pesticides against gram pod borer Helicoverpa armigera (Hubner) on chickpea (Cicer arietinum L.)

Evaluation of six insecticides viz., Azadiractin1% (1000ppm) Neem oil, Baeuveria bassiana 1% WP, Bacillus thuriengiensis var kurstaki 5% WP, Metarhizium anisopliae 1.0% WP, Verticillium lecanii 1.15% WP and Ha NPV 250 LE were evaluated against Gram Pod Borer (Helicoverpa armigera Hubner) larvae. The Gram Pod Borer (GPB) larval population was counted on 5 randomly selected plants at 24 hr. before spray and at 3, 7 and 10 days after spray. The two-years experiment was conducted during Rabi 2018-19 and 2019-20 at the Rehti Farm of school of Agriculture, Mhow, experimental field of Department of Entomology, BRAUSS, (MP). All the biopesticides significantly reduced the GPB larval population. The Pooled GPB population varied from 2.30 to 2. 50 larvae/plant during Rabi season one day prior tothe first spray. The population was significantly lower with Bacillus thuriengiensis var kurstaki 5% WP, followed by Ha NPV 250 LE, Baeuveria bassiana 1% WP, Metarhizium anisopliae 1.0% WP and Azadiractina 1% (1000ppm) Neem oil, these five biopesticides are showing best management effects on the GPB larvae and pod damaging per cent and remain, and least effective treatment was Verticillium lecanii 1.15% WP. The maximum reduction of larval population and pod damaging per cent. In Rabi season, the highest chickpea grain yield was obtained with Bacillus thuriengiensis var kurstaki at 5% WP.

Infestation of Helicoverpa armigera (Hubner) and Ostrinia furnacalis Guenee on three tropical altitude variations

Pest infestation is a major problem in corn cultivation because it causes a decrease in crop productivity or even crop failure. This study aimed to evaluate the level of crop damage caused by Helicoverpa armigera and Ostrinia furnacalis in three tropical altitude variations. Ten hybrid corns from cross-breeding strains and three commercial hybrid corn varieties were evaluated at three locations with different altitudes, classified as lowland (30 masl), midland (600 masl), and highland (1000 masl). The evaluation was carried out on the level of crop damage and plant resistance. The results showed that the highest percentage of H. armigera attack on hybrid corn was 75% at Caps 17B x Caps 23 (moderately susceptible) at the lowland and the lowest was 8% at Caps 2 x Caps 17A (resistant). The percentage of H. armigera attack was 100% at Caps 15 x Caps 22 (very susceptible) and the lowest was the evaluation of Caps 5 x Caps 17B was 58% (susceptible) at the midland. Meanwhile, the highest attack percentage was 92% on the Caps 17A x Caps 17B, Caps 17A x Caps 22, and Caps 5 x Caps 22 hybrids (very susceptible), while the lowest was 67% on the Caps 3 x Caps 17B and Secada hybrids (moderately susceptible) at the highland. O. furnacalis attack showed that all hybrid corns were classified as resistant except for Caps 5 x Caps 22 and Paragon was moderately resistant with a percentage attack of 25% at lowland. At the midland, Caps 5 x Caps 17B hybrid corn was classified as very susceptible with an attack of 92%, while Caps 15 x Caps 22 was classified as resistant with an attack percentage of 8%. At an altitude of 1000 masl, Caps 17A x Caps 17B, Caps 3 x Caps 17A, and Caps 5 x Caps 17B were moderately resistant with an attack percentage of 33% and other hybrids were resistant with an attack percentage of 8%.

Study on Farnesol dehydrogenase as a promising target for management of Helicoverpa armigera

Study on Farnesol dehydrogenase as a promising target for management of Helicoverpa armigera

Simple cost‐effective larval injection method for dsRNA delivery to induce RNAi response in Helicoverpa armigera (Hübner)

AbstractMicroinjection is considered as an effective method for dsRNA delivery in insects. It also facilitates the delivery of a precise quantity of dsRNA in the host insect, inducing an efficient RNAi response. However, the microinjection method needs prior optimization of several parameters like concentration of dsRNA, site of injection, developmental stage of insect etc. for inducing effective RNAi response. Moreover, sophisticated microinjection devices are largely expensive with high maintenance cost. The Old‐World bollworm, Helicoverpa armigera (Hübner) is known to be a detrimental polyphagous pest with widespread infestations across the globe. In the present study, we demonstrate a low‐cost and effective dsRNA delivery method for inducing RNAi response in H. armigera with the aid of basic insulin injection syringe and fabricated micropipette tip. In order to validate the RNAi response following dsRNA injection, we have selected three key genes from the chitin biosynthesis pathway of the insect. Besides these, argonaute 1 (ago1) was also used as an indicator gene for dsRNA‐mediated RNAi induction. Delivery of dsRNA using injection with insulin syringe caused significant upregulation of the ago1 gene in the insect irrespective of any of the three target genes concerned viz. HaNAGK (3.9 fold; p < 0.001), HaAGM (6.3 fold; p < 0.001) and HaUAP (5.9 fold; p < 0.01) respectively, as compared to control injected with nuclease‐free water. The dsRNA‐injected insects showed aberrant developmental symptoms typical of impeded chitin synthesis, eventually leading to anomalous ecdysis with substantial mortality (up to 69.04%), as compared to controls. The described protocol reduces insect injury, enabling easy restraining of larva and quick execution of dsRNA injection with efficient RNAi response.

Distribution and Organization of Descending Neurons in the Brain of Adult Helicoverpa armigera (Insecta).

The descending neurons (DNs) of insects connect the brain and thoracic ganglia and play a key role in controlling insect behaviors. Here, a comprehensive investigation of the distribution and organization of the DNs in the brain of Helicoverpa armigera (Hübner) was made by using backfilling from the neck connective combined with immunostaining techniques. The maximum number of DN somata labeled in H. armigera was about 980 in males and 840 in females, indicating a sexual difference in DNs. All somata of DNs in H. armigera were classified into six different clusters, and the cluster of DNd was only found in males. The processes of stained neurons in H. armigera were mainly found in the ventral central brain, including in the posterior slope, ventral lateral protocerebrum, lateral accessory lobe, antennal mechanosensory and motor center, gnathal ganglion and other small periesophageal neuropils. These results indicate that the posterior ventral part of the brain is vital for regulating locomotion in insects. These findings provide a detailed description of DNs in the brain that could contribute to investigations on the neural mechanism of moth behaviors.

Induced defense responses in cultivated and wild chickpea genotypes against Helicoverpa armigera infestation.

Five desi (GL 12,021, GL 29,095, GL 29,078, H11 22 and CSJ 515) and three wild (GLW 22, GLW 58 and GLW 187) chickpea cultivars showed induced defense response against Helicoverpa armigera infestation as a result of enhanced activities of superoxide dismutase, catalase, peroxidase, ascorbate peroxidase, glutathione reductase, polyphenol oxidase, phenylalanine ammonia lyase, tyrosine ammonia lyase in leaves, pod walls and seeds. Catalase activity increased in leaves of GL 12,021, H11 22, GL 29,095, CSJ 515, GLW 22, and GL 29,078 after infestation compared to resistant check; catalase and peroxidase activities in GL 29,095 and GL 29,078; ascorbate peroxidase and glutathione reductase activities in leaves of GLW 58. The increased activity of superoxide dismutase in pod wall of H1122; catalase in pod wall of 29,078, GL 29,095 and GL 22; ascorbate peroxidase and glutathione reductase in pod wall of GLW 58; phenylalanine ammonia lyase and tyrosine ammonia lyase in pod wall of GLW 187, H11 22, GL 20,978, GLW 22 and GLW 58 after infestation as compared to resistant check might be responsible for mitigating infestation induced oxidative stress. MDA content decreased in leaves, pod wall and seeds of GLW 187 and GL 12,021 after infestation. Lower percent pod damage (9.58-12.44%) in GL 12,021, GLW 187, GL 29,095, H11 22, GL 29,078, GLW 22 and GLW 58 as compared to resistant (16.18%) and susceptible (21.50) checks might be attributed to differential induced defense mechanism in them. The identified desi and wild genotypes might be used in breeding program to develop cultivars with improved resistance to herbivore.

Fluorescent Nanoparticle-RNAi-Mediated Silencing of Sterol Carrier Protein-2 Gene Expression Suppresses the Growth, Development, and Reproduction of Helicoverpa armigera.

Helicoverpa armigera is a polyphagous destructive lepidopteran pest with strong Bacillus thuringiensis (Bt) resistance. Cholesterol, a vital component for insect growth, can only be obtained from food, and its transfer and metabolism are regulated by sterol carrier protein-2 (SCP-2). This study examined whether H. armigera SCP-2 (HaSCP-2) gene expression, involved in cholesterol absorption, can be silenced by nanocarrier fluorescent nanoparticle-RNA interference (FNP-RNAi) by larval feeding and whether the silencing affected H. armigera development. Fluorescence microscopy showed that nanoparticle-siRNA was distributed in Ha cells and the larval midgut. FNP-HaSCP-2 siRNA suppressed HaSCP-2 expression by 52.5% in H.armigera Ha cells. FNP can effectively help deliver siRNA into cells, protect siRNA, and is not affected by serum. FNP-siRNA in vivo biological assays showed that HaSCP-2 transcript levels were inhibited by 70.19%, 68.16%, and 67.66% in 3rd, 4th, and 5th instar larvae, leading to a decrease in the cholesterol level in the larval and prepupal fatbodies. The pupation rate and adult emergence were reduced to 26.0% and 56.52%, respectively. This study demonstrated that FNP could deliver siRNA to cells and improve siRNA knockdown efficiency. HaSCP-2 knockdown by FNP-siRNA in vivo hindered H. armigera growth and development. FNP could enhance RNAi efficiency to achieve pest control by SCP-2-targeted FNP-RNAi.

Sex Pheromone Receptor-Derived Peptide Biosensor for Efficient Monitoring of the Cotton Bollworm Helicoverpa armigera.

The cotton bollworm, Helicoverpa armigera (H. armigera), causes damage to a wide range of cultivated crops and is one of the pests with the greatest economic importance for global agriculture. Currently, the detection of H. armigera is based on manual sampling. A low limit of detection (LOD), convenient, and real-time monitoring method is urgently needed for its early warning and efficient management. Here, we characterized the amino acid sequence in the sex pheromone receptors (SPRs) recognizing the pheromone components of H. armigera by three-dimensional (3D) modeling and molecular docking. Next, sex pheromone receptor-derived peptides (SPRPs) were synthesized and conjugated to nanotubes by chemical connection. The modified nanotubes were used to fabricate a sensor capable of real-time monitoring of gaseous sex pheromone compounds with a low LOD (∼10 ppb for Z11-16:Ald) and selectivity, and the sensor was able to detect a single live H. armigera. Furthermore, the developed biosensor allowed direct monitoring of the pheromone release dynamics by female H. armigera and showed that the release was instantly reduced in response to light. Here, we report the first demonstration of a biosensing method for detecting gaseous sex pheromones and live H. armigera. The findings show the great potential of the SPRP sensor for broad applications in insect biology study and infestation monitoring.

Population Genomics of Nonrecessive Resistance to Bt Toxin Cry1Ac in Helicoverpa armigera From Northern China.

Transgenic crops that produce insecticidal proteins from Bacillus thuringiensis (Bt) have provided control of some key pests since 1996. However, the evolution of resistance by pests reduces the benefits of Bt crops. Resistance to Bt crops that is not recessively inherited is especially challenging to manage. Here we analyzed nonrecessive resistance to Bt toxin Cry1Ac in eight field populations of Helicoverpa armigera sampled in 2018 from northern China, where this global pest has been exposed to Cry1Ac in Bt cotton since 1997. Bioassays revealed 7.5% of field-derived larvae were resistant to Cry1Ac of which 87% had at least one allele conferring nonrecessive resistance. To analyze this nonrecessive resistance, we developed and applied a variant of a genomic mapping approach called quantitative trait locus (QTL)-seq. This analysis identified a region on chromosome 10 associated with nonrecessive resistance to Cry1Ac in all 21 backcross families derived from field-collected moths. Individual sequencing revealed that all 21 field-collected resistant grandparents of the backcross families had a previously identified dominant point mutation in the tetraspanin gene HaTSPAN1 that occurs in the region of chromosome 10 identified by QTL-seq. QTL-seq also revealed a region on chromosome 26 associated with nonrecessive resistance in at most 14% of the backcross families. Overall, the results imply the point mutation in HaTSPAN1 is the primary genetic basis of nonrecessive resistance to Cry1Ac in field populations of H. armigera from northern China. Moreover, because nonrecessive resistance is predominant, tracking the frequency of this point mutation could facilitate resistance monitoring in the region.

Invitro rearing of parasitoids

Since 2015, the studies on in vitro rearingBraconidaeandTrichogrammatidae(B. habetorSay,B. greeniandT. pintoe, T. evanescens, T. chilonis) have been conducted successfully in Uzbekistan. For these parasites, cooking and the three main types of media were made from the hemolymph of the wax moth (G. melonnella) and cotton wormHelicoverpa armigera (Heliothis armigera), egg yolk, natural milk 10%. The simulated "host-eggs" and "larvae" are made of polyethylene or polypropylene semi spherical capsules, containing artificial diets, in which insectan pupal hemolymph is the main component. Mass production of in vitro rearedBraconidaeandTrichogrammatidaeits utilization in the fields showed good effectiveness in controlling cotton bollworm. In the article researches were given about creating artificial medium of diets in order to growbraconand choosing effective medium of diets. In our researches medium of diets which consists of some components was created and they were harmed withbracongenerations. According to it, generation of bracon’s nutrition and developing three main types of medium were produced in order to rear bracon parasite that was composed wax moths (G.melonnellan) and (heliothis armigera) hemolymph, egg yolk, natural milk.

Comparative efficacy of insecticides and biopesticides against cowpea pod borer [Helicoverpa armigera (Hubner)] infesting cowpea (Vigna unguiculata L.)

Comparative efficacy of insecticides and biopesticides against cowpea pod borer [Helicoverpa armigera (Hubner)] infesting cowpea (Vigna unguiculata L.)

Efficacy of Beneficial Fungi Isolates in <i>Solanum lycopersicum</i> L. Protection against Lepidopteran Insects through a Leaf Inoculation Technique

Helicoverpa armigera is a key insect pest of tomatoes reducing drastically yields. The effect of the endophytic colonization of tomato plants by Beauveria bassiana using leaf spray as an inoculation method on damage and survival of H. armigera was assessed in a screen house. Two B. bassiana isolates (Bb 115 and Bb 11) and two tomato varieties (a local variety Tounvi and an improved variety Padma) were included in the study. The adaxial and abaxial leaf surfaces were sprayed at a concentration of 107 conidia/ml and 109 conidia/ml for each isolate and each of the two tomato varieties. Thirty days after inoculation, five discs of tomato leaf and tomato root were cut for each isolate, each concentration per isolate and for each variety. The samples were incubated at room temperature (28°C ± 2°C) and periodically checked for fungal growth. Larval survival was checked and a damage assessment was done on tomato flowers and the leaves. The results show that the lowest Mean Survival Times (MSTs) were recorded on larvae feeding on plants inoculated with Bb 11 (4.2 ± 0.8 days against 11.5 ± 0.2 days for control). Compared to the other treatments, low damage rates of the flowers of the improved variety inoculated with Bb 11 at 109 conidia/ml were recorded from the 6th Day After Inoculation (DAI). This rate remains low until the end of treatment. Overall flower damage was lower than leaf damage. The results showed large differences in pathogenicity, with most endophytic isolate belonging to Bb 11 when inoculated at 109 conidia/ml using the leaf spraying technique. Data were discussed with regard to the use of endophytism B. bassiana in an integrated tomato pest control approach.

Evaluation of insecticide and pheromone trap efficacy for management of fruit borer (Helicoverpa armigera) in tomato

Evaluation of insecticide and pheromone trap efficacy for management of fruit borer (Helicoverpa armigera) in tomato

Effect of newer insecticide molecules against fruit borer, Helicoverpa armigera (Hubner) in tomato

Effect of newer insecticide molecules against fruit borer, Helicoverpa armigera (Hubner) in tomato

Bioefficacy of certain chemicals and biopesticides against Helicoverpa armigera (Hubner) on cowpea [Vigna unguiculata (L.)

Bioefficacy of certain chemicals and biopesticides against Helicoverpa armigera (Hubner) on cowpea [Vigna unguiculata (L.)

Sublethal effects of fenoxycarb on female reproduction in Helicoverpa armigera (Lepidoptera: Noctuidae)

Abstract The cotton bollworm, Helicoverpa armigera (Hünber) (Lepidoptera: Noctuidae), is a polyphagous pest that causes severe damage to economical crops in most parts of the world. The juvenile hormone analogues are a group of insect growth regulators that increase larval ages and disrupt larval development. Moreover, they affect reproductive system in adult insects. In this study, the effects of sublethal doses of fenoxycarb on fecundity, fertility, and longevity parameters, as well as on oocyte size, ecdysteroid titer in ovaries, and expression level of the ultraspiracle (USP), ecdysone receptor (EcR), hormone receptor 3 (HR3), and vitellogenin (Vg) genes in adult female H. armigera, were examined. Feeding on artificial diet containing fenoxycarb (LC10 and LC25) significantly decreased the percentage of larval survival rate, pupation rate, pupal weight, fecundity, fertility, and oviposition period. It also clearly shortened female longevity. Fenoxycarb treatment suppressed the expression of the USP, EcR, and Vg genes in H. armigera but had no effect on the HR3 gene expression level in either pupae or adults. Overall, our results show that using fenoxycarb as a juvenile hormone analogue can reduce reproduction in H. armigera and may work as an alternative to the use of insecticides for controlling this important agricultural pest.