Control Of Helicoverpa Armigera Research Articles

Review on different biocontrol agents used in control of Helicoverpa armigera (Hubner)

H. armigera is a major polyphagous pest for agricultural and horticultural crops. It has wide range of host plants. It is difficult to control due to its polyphagous nature, high fecundity, mobility and diapause. The control of Helicoverpa armigera mainly depend on chemicals, but heavy and continuous use of it lead to resistance to different group of insecticides like cyclodienes, pyrethoids, carbamates and organophosphates. To avoid this resistance we should focus on other methods of control like host plant resistance like non-preference, antibiosis and tolerance. Cultural operations like right time of sowing, ploughing, nutrient management, spacing, crop rotation and biological control by using egg parasitoids like Trichogramma chilonis, larval parasitoids like Compolestis chlorideae, bacteria like Bacillus thuringensis, fungi like Beauveria bassiana and virus like HaNPV.

NATURAL CONTROL OF Helicoverpa armigera (LEPIDOPTERA: NOCTUIDAE) PUPAE IN ORGANIC AND CONVENTIONAL MAIZE CROPS

The natural biological control of soil pests is poorly studied. Notably, the control of Helicoverpa armigera in the pupae stage is unknown. To increase knowledge about the control of this pest in organic and conventional maize crop, tests were conducted to verify if the duration of pupae availability in days, the type of crop treatment (organic and conventional), the stage of crop development, and the depth of the soil significantly affect predation by natural enemies. The pupae availability time (days) in the soil did not affect their removal by natural enemies. However, in the fallow stage, on the surface and in the reproductive phase, the predation was higher. In organic maize, predation was 15% higher when compared to conventional maize. The rupture of the soil and the possible losses associated with beneficial fauna were the main factors responsible for higher predation during fallow, so conservationist practices usually used in organic treatment are the main reason for higher predation in this type of crop. There is a significant decrease in the control of H. armigera pests by natural enemies when maize is grown using conventional practices, what reinforces the importance of the conservation techniques used in maize crops.

NATURAL CONTROL OF Helicoverpa armigera (LEPIDOPTERA: NOCTUIDAE) PUPAE IN ORGANIC AND CONVENTIONAL MAIZE CROPS

The natural biological control of soil pests is poorly studied. Notably, the control of Helicoverpa armigera in the pupae stage is unknown. To increase knowledge about the control of this pest in organic and conventional maize crop, tests were conducted to verify if the duration of pupae availability in days, the type of crop treatment (organic and conventional), the stage of crop development, and the depth of the soil significantly affect predation by natural enemies. The pupaeavailability time (days) in the soil did not affect their removal by natural enemies. However, in the fallow stage, on the surface and in the reproductive phase, the predation was higher. In organic maize, predation was 15% higher when compared to conventional maize. The rupture of the soil and the possible losses associated with beneficial fauna were the main factors responsible for higher predation during fallow, so conservationist practices usually used in organic treatment are the main reason for higher predation in this type of crop. There is a significant decrease in the control of H. armigera pests by natural enemies when maize is grown using conventional practices, what reinforces the importance of the conservation techniques used in maize crops.

Combined application of chitinolytic bacterium Paenibacillus sp. D1 with low doses of chemical pesticides for better control of Helicoverpa armigera

ABSTRACTHelicoverpa armigera is a serious pest of Cajanus cajan in many parts of world. Rapid development of resistance against number of insecticides and cry toxin-based biocontrol agents has led to search for biocontrol agents with alternative mode of action. The ability of chitinolytic bacteria to degrade vital chitinous structure in insects suggests their potential in insect control. The present investigation was carried out to study insect control potential of a high chitinase producing bacterium, Paenibacillus sp. D1. Biocontrol studies with Helicoverpa larvae showed Paenibacillus sp. D1 and its chitinase to be potent antifeedant that reduced the feeding rate and body weight of the larvae. The decreased body weight was attributed to hydrolysis of the chitinous structures of the larvae. This was evident from decrease in the total chitin content and increased mortality of the larvae fed on the leaves treated with Paenibacillus sp. D1 and chitinase as compared to untreated controls. A combined dose of Paenibacillus sp. D1 or its chitinase with an organophosphate insecticide, acephate, was found to be more lethal than their individual treatments suggesting integrated insect control potential of the bacterium.

Organisms with potential to assist in the control of Helicoverpa armigera in Australian cotton production systems

Helicoverpa armigera was once considered the most important insect pest to Australian cotton production. The introduction of genetically modified cotton altered this status and made this insect pest control less chemically dependent, but resistance to the insecticidal compounds expressed in genetically modified cotton has evolved in laboratory-reared H. armigera populations and is shown to exist in natural populations. Preventing the development of resistance in field populations is complicated by the over wintering of potentially resistant individuals in the soil. Biocontrol may assist in reducing the population of resistant individuals. Several projects investigating the ecology of Australian cotton highlighted the existence of several native organisms with ability to limit the growth or utilise H. armigera as a host. The work reported here set about establishing the presence of such organisms in Australian cotton soils by recovering them from soil and farm-collected H. armigera that exhibited abnormal growth, disease or death. The recovered organisms were identified as the fungi Lecanicillium lecanii, Actinomucor elegans and several Aspergillus species. L. lecanii was subsequently shown to reduce moth emergence to 56% of the larvae to which it was applied. We also identified a species of Rhabditis nematode, which killed 34% of the larvae to which it was applied and reduced moth emergence to 28%. In light of these observations these organisms are reported as potential candidates for biological control of H. armigera.

Compatibility of Orius laevigatus and Cheiracanthium pelasgicum for predation on Helicoverpa armigera eggs: effects of density and day/night activity on intraguild predation

Intraguild predation (IGP) among predatory arthropods can impair pest control efforts and endanger the joint-action compatibility of groups of natural enemies. The present study used plant microcosms to examine IGP of Cheiracanthium pelasgicum (C. L. Koch) (Araneae: Miturgidae) on minute pirate bugs Orius laevigatus (Fieber) (Hemiptera: Anthocoridae), two of the major lepidopteran-egg predators in southern Spanish cotton fields, and its effects on the control of Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae) eggs. Intensive unidirectional IGP of C. pelasgicum on O. laevigatus was observed under plant arena conditions: over 90 % of minute bugs were killed by spiders in the first 24 h. However, no negative interaction between C. pelasgicum and minute pirate bugs was found under different egg-density conditions with Orius alone, and the combination of two predator treatments displayed significantly higher predation rates than the spider-alone treatment after 24 h. Increased egg density did not affect control by predators, nor did it prompt a significant reduction in IGP. During a day–night bioassay, negative interaction between the two predators was found under night conditions, impacting on egg predation rates due to the combination of two predators. Predation of spiders on H. armigera eggs took place mainly at night, while predation by minute bugs was recorded both by day and by night. Finally, IGP by C. pelasgicum on minute pirate bugs was significantly higher by night. These outcomes demonstrate that diurnal and more intensive nocturnal IGP by spiders on minute pirate bugs had a moderate impact on the early control of H. armigera, with no negative effects after 24 h.

Efficacy of botanical extracts and entomopathogens on control of Helicoverpa armigera and Spodoptera litura

Interest in biological control of insect-pests of economically important plants has been stimulated in recent years by trends in agriculture towards greater sustainability and public concern about the use of hazardous pesticides. Botanicals and microorganisms have the capability to synthesize biologically active secondary metabolites such as antibiotics, herbicides and pesticides. In this investigation, washings of herbal vermicompost (called biowash; viz. Annona, Chrysanthemum, Datura, Jatropha, Neem, Parthenium, Pongamia, Tridax and Vitax) and plant growth promoting (PGP) bacteria [viz. Bacillus subtilis (BCB-19), Bacillus megaterium (SB-9), Serratia mercescens (HIB-28) and Pseudomonas spp. (SB-21)] and fungus (Metarhizium anisopliae) were evaluated for their efficacy against Helicoverpa armigera and Spodoptera litura. When the feed was treated with crude biowash for healthy larvae (4-day old), 42 and 86% mortality and 32 and 71% weight reduction over control was reported for H. armigera, while in the case of S. litura, it was between 46 and 74% larval mortality and 47 and 77% weight reduction over control.When healthy larvae were treated with PGP bacteria and fungus, the mortality rate varied between 59 and 73%, with 55 and 92% weight reduction over control on H. armigera, while for S. litura, 54 and 72% larval mortality and 44 and 79% weight reduction over control was reported. The results of the compatibility studies (entomopathogenic potential biowash of the botanicals with PGP bacteria and fungus) indicate that there was no definite sign of suppression of any of the botanicals on the PGP bacteria and fungus, except Datura with B. subtilis BCB-19, whereas, there was definite sign of enhanced growth of B. megaterium SB-9 with all the botanicals. Compatibility studies between PGP bacteria and fungus showed that all bacteria are compatible with each other except M. anisopliae. Crude biowash of the promising botanicals (Annona, Datura, Jatropha, Neem, Parthenium and Pongamia) were further fractionated on C18 solid phase extraction cartridge (SPE) and the resultant adsorbed and non-adsorbed fractions were tested against H. armigera. Results indicate that both adsorbed as well as non-adsorbed fractions showed significant mortality on H. armigera. Adsorbed fractions of all the six biowash showed mortality between 81 and 93% (64 and 73% for non-adsorbed fraction) over control and the weight reduction of the larvae was found between 73 and 91% (80 and 97% for non-adsorbed fraction) over control. It was therefore concluded that the aforementioned six botanicals and five entomopathogens has great potential in the management of H. armigera and S. litura. Key words: Botanicals, entomopathogens, biowash, secondary metabolites,Helicoverpa armigera, Spodoptera litura. ta-lactamases, urinary tract infections,Escherichia coli, Klebsiella pneumoniae.

Efficacy of botanical extracts and entomopathogens on control of Helicoverpa armigera and Spodoptera litura

Interest in biological control of insect-pests of economically important plants has been stimulated in recent years by trends in agriculture towards greater sustainability and public concern about the use of hazardous pesticides. Botanicals and microorganisms have the capability to synthesize biologically active secondary metabolites such as antibiotics, herbicides and pesticides. In this investigation, washings of herbal vermicompost (called biowash; viz. Annona, Chrysanthemum, Datura, Jatropha, Neem, Parthenium, Pongamia, Tridax and Vitax) and plant growth promoting (PGP) bacteria [viz. Bacillus subtilis (BCB-19), Bacillus megaterium (SB-9), Serratia mercescens (HIB-28) and Pseudomonas spp. (SB-21)] and fungus (Metarhizium anisopliae) were evaluated for their efficacy against Helicoverpa armigera and Spodoptera litura. When the feed was treated with crude biowash for healthy larvae (4-day old), 42 and 86% mortality and 32 and 71% weight reduction over control was reported for H. armigera, while in the case of S. litura, it was between 46 and 74% larval mortality and 47 and 77% weight reduction over control.When healthy larvae were treated with PGP bacteria and fungus, the mortality rate varied between 59 and 73%, with 55 and 92% weight reduction over control on H. armigera, while for S. litura, 54 and 72% larval mortality and 44 and 79% weight reduction over control was reported. The results of the compatibility studies (entomopathogenic potential biowash of the botanicals with PGP bacteria and fungus) indicate that there was no definite sign of suppression of any of the botanicals on the PGP bacteria and fungus, except Datura with B. subtilis BCB-19, whereas, there was definite sign of enhanced growth of B. megaterium SB-9 with all the botanicals. Compatibility studies between PGP bacteria and fungus showed that all bacteria are compatible with each other except M. anisopliae. Crude biowash of the promising botanicals (Annona, Datura, Jatropha, Neem, Parthenium and Pongamia) were further fractionated on C18 solid phase extraction cartridge (SPE) and the resultant adsorbed and non-adsorbed fractions were tested against H. armigera. Results indicate that both adsorbed as well as non-adsorbed fractions showed significant mortality on H. armigera. Adsorbed fractions of all the six biowash showed mortality between 81 and 93% (64 and 73% for non-adsorbed fraction) over control and the weight reduction of the larvae was found between 73 and 91% (80 and 97% for non-adsorbed fraction) over control. It was therefore concluded that the aforementioned six botanicals and five entomopathogens has great potential in the management of H. armigera and S. litura. Key words: Botanicals, entomopathogens, biowash, secondary metabolites,Helicoverpa armigera, Spodoptera litura. ta-lactamases, urinary tract infections,Escherichia coli, Klebsiella pneumoniae.

Monitoring and Control of Helicoverpa armigera by Synthetic Pheromone Traps in Peas, Pisum sativum

Monitoring and Control of Helicoverpa armigera by Synthetic Pheromone Traps in Peas, Pisum sativum

Scouting and Control of Helicoverpa armigera by Synthetic Pheromone Technology in Apple

Scouting and Control of Helicoverpa armigera by Synthetic Pheromone Technology in Apple

Effects of cowpea intersowing and insecticide application on Helicoverpa armigera Hubner (Lepidoptera: Noctuidae) and its natural enemies in pigeonpea intercropped with sorghum

In a split-plot experiment, Helicoverpa armigera eggs, larvae, and H. armigera egg predators were sampled weekly or biweekly to test whether intersowing of cowpea could increase the natural control of Helicoverpa armigera in pigeonpea that had been relay intercropped with sorghum, and to test the effect of an insecticide treatment on the H. armigera population and on its natural enemies. Cowpea intersowing resulted in higher numbers of H. armigera eggs and larvae per pigeonpea plant in the first 3 weeks ofsampling, whereas the predator species studied were not significantly affected, possibly due to the small overlap between the composition of natural enemies in sorghum and pigeonpea: the two beneficial species Orius tantillus (Motschulsky) (Heteroptera: Anthochoridae) and Menochilus sexmaculatus F. (Coleoptera: Coccinellidae), very common predators in sorghum, occurred in low numbers in pigeonpea, where the most common predators were Cheiracanthium inornatum O.P.-Cambridge (Aranea: Clubionidae) and anthicids (Anthicus sp., Formicomus sp.) (Coleoptera: Anthicidae). Insecticide treatment resulted in significantly higher number of H. armigera eggs per plant compared with no insecticide treatment, the effect being most pronounced immediately after the treatment. Insecticide had no significant effect on the number of H. armigera larvae per plant, but it had a strong adverse effect on C. inornatum and anthicids.

Natural Control of Helicoverpa armigera in Sunflower: Assessment of the Role of Predation

In three field experiments in Kenya , the seasonal population trend of Helicoverpa armigera (Hubner) (= Heliothis armigera) in sunflower was followed in plots from which predators were excluded and in plots from which predators were not excluded . In experiment 1 , complete exclusion of crawling predators (predominantly Pheidole spp . of ants occurring at densities of 25 per plant) resulted in H. armigera densities 3 - 5 times higher than in plots where ants were not excluded . Pheidole sp . had more impact on young H. armigera larvae (instars 2 - 3) than on older larvae (instars 4 - 6) . The results of experiment 2 were less striking , because H. armigera infestation was low , and ant densities were moderate . Here , Myrmicaria spp . and Camponotus spp . were the predominant ants . Exclusion of ants resulted in a 1 . 8 - fold increase in densities of large H. armigera instars . In experiment 3 , the impact of predators on H. armigera was studied under three conditions: exclusion of crawling predators , exclusion of both crawling and flying predators , and the control where no predators were excluded . To evaluate the role of predation in total mortality , the recruitment of H. armigera larvae was determined with Southwood and Jepson ' s graphical method , and recruitment of newly laid eggs was directly measured on trap plants . Because it was difficult to detect older eggs due to colour change , the direct measurement of egg recruitment was superior to the graphical method . Ants and Anthocoridae were the dominant predators . M ortality from egg to older larvae (instars 4 - 6) was 73 - 78% . Exclusion of ants and anthocorids did not affect the densities of H. armigera larvae . Anthocorid predators increased only after the main oviposi tion peak of H. armigera and , therefore , their exclusion had little impact on the pest . Ant density was considerably lower than in experiment 1 , and did not significantly suppress H. armigera.

Influence of Lablab Bean Varieties on the Nuclear Polyhedrosis Virus Mortality in Larvae of Helicoverpa armigera (Hbn.))

The nuclear polyhedrosis virus (NPV) has heen found to be effective in the control of Helicoverpa armigera (Hbn.) on several crops (Jayaraj et al ., 1989) including lablab been (Jayaraj et al., 1987). Studies on the influence of varieties of host plants on the activity of NPV are rather limited. Rabindra et al. (1992) studied the effect of different chickpea varieties on the NPV - control of H. armigera . The present study was carried out to find out the influence of lablab bean Dolichos lab lab (L.) varieties on the mortality caused by NPV in larvae of H.armigera .