Fitness Costs of Two Maize Lepidopteran Pests Fed on Bacillus thuringiensis (Bt) Diets Enriched with Vitamins A and C

Serious malnutrition problems occur in developing countries where people’s diets are mainly based on staple crops. To alleviate this, high-production crops are being developed that are better adapted to climate change, enriched in micronutrients and vitamins, or resistant to pests. In some cases, new varieties have been developed with several of the characteristics mentioned above, such as biofortified and pest-resistant crops. The development of biofortified Bacillus thuringiensis (Bt) crops raises the question of whether vitamin enrichment of Bt crops can in any way favor those pests that are not very susceptible to the Bt toxin that feed on these crops, such as Helicoverpa armigera (Hübner) or Mythimna unipuncta (Haworth) (Lepidoptera: Noctuidae). In this study, the response to a Bt diet enriched with vitamins A (β-carotene) and C (ascorbic acid) was somewhat different between the two species. M. unipuncta was less sensitive to the toxin than H. armigera, although the ingestion of the Bt diet resulted in oxidative stress (longer larval development and lower pupal weight) which was not mitigated by the vitamins. However, the two vitamins reduced the mortality of H. armigera larvae fed on a Bt-enriched diet; in addition, ß-carotene reduced the activity of the antioxidant glutathione S-transferase (GST) of both species, suggesting it has an antioxidant role. The results obtained here indicate that biofortified Bt crops will not favor the development of H. armigera very much and will not affect M. unipuncta’s development at all, although the effect of the increase in vitamins may be very variable and should be studied for each specific phytophagous.

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Effectiveness of Bacillus thuringiensis-Transgenic Chickpeas and the Entomopathogenic Fungus Metarhizium anisopliae in Controlling Helicoverpa armigera (Lepidoptera: Noctuidae)

Applied and Environmental Microbiology ◽

10.1128/aem.00484-08 ◽

2008 ◽

Vol 74 (14) ◽

pp. 4381-4389 ◽

Cited By ~ 20

Author(s):

N. C. Lawo ◽

R. J. Mahon ◽

R. J. Milner ◽

B. K. Sarmah ◽

T. J. V. Higgins ◽

...

Keyword(s):

Bacillus Thuringiensis ◽

Helicoverpa Armigera ◽

Metarhizium Anisopliae ◽

Entomopathogenic Fungus ◽

Fitness Costs ◽

Cry Proteins ◽

Bt Crops ◽

Helicoverpa Armígera ◽

Lepidoptera Noctuidae ◽

Increased Susceptibility

ABSTRACT The use of genetically modified (Bt) crops expressing lepidopteran-specific Cry proteins derived from the soil bacterium Bacillus thuringiensis is an effective method to control the polyphagous pest Helicoverpa armigera. As H. armigera potentially develops resistance to Cry proteins, Bt crops should be regarded as one tool in integrated pest management. Therefore, they should be compatible with biological control. Bioassays were conducted to understand the interactions between a Cry2Aa-expressing chickpea line, either a susceptible or a Cry2A-resistant H. armigera strain, and the entomopathogenic fungus Metarhizium anisopliae. In a first concentration-response assay, Cry2A-resistant larvae were more tolerant of M. anisopliae than susceptible larvae, while in a second bioassay, the fungus caused similar mortalities in the two strains fed control chickpea leaves. Thus, resistance to Cry2A did not cause any fitness costs that became visible as increased susceptibility to the fungus. On Bt chickpea leaves, susceptible H. armigera larvae were more sensitive to M. anisopliae than on control leaves. It appeared that sublethal damage induced by the B. thuringiensis toxin enhanced the effectiveness of M. anisopliae. For Cry2A-resistant larvae, the mortalities caused by the fungus were similar when they were fed either food source. To examine which strain would be more likely to be exposed to the fungus, their movements on control and Bt chickpea plants were compared. Movement did not appear to differ among larvae on Bt or conventional chickpeas, as indicated by the number of leaflets damaged per leaf. The findings suggest that Bt chickpeas and M. anisopliae are compatible to control H. armigera.

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Bollworm (Lepidoptera: Noctuidae) Development and Movement on Bacillus thuringiensis-treated Cotton Leaves

Journal of Entomological Science ◽

10.18474/0749-8004-36.1.23 ◽

2001 ◽

Vol 36 (1) ◽

pp. 23-33 ◽

Cited By ~ 6

Author(s):

Muhammad Ashfaq ◽

S. Y. Young ◽

R. W. McNew

Keyword(s):

Bacillus Thuringiensis ◽

Helicoverpa Zea ◽

Leaf Surface ◽

Larval Mortality ◽

Lethal Dose ◽

Crop Protection ◽

Pupal Weight ◽

Larval Weight ◽

Lepidoptera Noctuidae ◽

Transfer Times

Larval mortality, survivorship and movement of the bollworm, Helicoverpa zea (Boddie), on and away from Bacillus thuringiensis-treated cotton leaves were investigated in the laboratory. Bacillus thuringiensis (Costar®, Novartis Crop Protection, Inc; Greensboro, NC) was applied to the upper surface of cotton leaves via a spray table in five concentrations, i.e., 0.0 (control), 0.14, 0.29, 0.58, and 1.15 kg/ha. Three-day-old H. zea larvae were released on treated leaves, kept at 30°C, and transferred to artificial diet after 12, 24, and 48 h. Significantly higher numbers of larvae were found on the lower than upper leaf surface after all three transfer times, but the numbers surviving in all treatments were similar to the control. Larval movement from the leaf to cup surface was significantly higher in B. thuringiensis-treated leaves than in the control. The mortality of larvae that were transferred from leaves to diet at 7 d after treatment was significantly higher in all treatments than in the control and highest at the highest rates (0.58 and 1.15 kg/ha). Data on survival of larvae at different locations suggest that for the first 24 h, the increase in the percentage of larvae on the inner cup surface in B. thuringiensis treatments was not due to larvae that had consumed a lethal dose, but an attempt to avoid the B. thuringiensis on the upper leaf surface. Highest larval weight was recorded in the control for all transfer times. The length of the larval period increased with the B. thuringiensis rate at the 12-h transfer. The pupal weight was reduced at the highest B. thuringiensis rates at the 48-h transfer.

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Spore-Toxin Interactions and Sublethal Effects of Bacillus thuringiensis in Spodoptera frugiperda and Pseudoplusia includens (Lepidoptera: Noctuidae)

Journal of Entomological Science ◽

10.18474/0749-8004-31.1.52 ◽

1996 ◽

Vol 31 (1) ◽

pp. 52-62 ◽

Cited By ~ 18

Author(s):

F. F. R. Nyouki ◽

J. R. Fuxa ◽

A. R. Richter

Keyword(s):

Bacillus Thuringiensis ◽

Life Span ◽

Spodoptera Frugiperda ◽

Sublethal Effects ◽

Synergistic Effects ◽

Pseudoplusia Includens ◽

Pupal Weight ◽

Median Lethal Concentrations ◽

Lepidoptera Noctuidae ◽

Sublethal Concentrations

Interactions between the spores and δ-endotoxins of Bacillus thuringiensis Berliner were tested in a low-susceptibility insect, Spodoptera frugiperda (J. E. Smith). The spores (formulation MYD™) and one δ-endotoxin (formulation MVP™) had additive effects on mortality at a MVP™ dose of 117,500 μg/g of diet (P < 0.01) and synergistic effects at a MVP™ dose of 235,000 μg/g diet (P < 0.01). The spores and another δ-endotoxin (formulation MYX™) were antagonistic at a MYX™ dose of 117,500 μg/g diet (P < 0.01) and additive at a MYX™ dose of 235,000 μg/g diet (P < 0.01). The two δ-endotoxin formulations were additive with one another (P < 0.01). Sublethal concentrations of MVP™ fed to larvae retarded the development of larvae and pupae for 5 d (P < 0.01) and 1.2 d (P < 0.01), respectively, and decreased pupal weight by 48 mg (P < 0.01). The spore formulation did not affect (P > 0.05) pupal weight or the life span of larvae or pupae. Median lethal concentrations of MVP™ and MYX™ were 6,904 and 7,561 × greater, respectively, in S. frugiperda than in Pseudoplusia includens (Walker). In P. includens, sublethal concentrations of MVP™, MYX™, and Dipel™ fed to larvae significantly (P < 0.05) reduced pupal weight and increased pupal life span compared to control insects. MVP™ and Dipel™ increased larval life span significantly (P < 0.05), but MYD™ did not.

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THE EFFECT OF Bacillus thuringiensis TOXIN Cry1A.105 AND Cry2Ab2 ON THE SURVIVAL OF THE NON-TARGET PEST, Spodoptera litura (PENGARUH TOKSIN Bacillus thuringiensis Cry1A.105 DAN Cry2Ab2 TERHADAP KELANGSUNGAN HIDUP HAMA BUKAN SASARAN, Spodoptera litura)

Jurnal Perlindungan Tanaman Indonesia ◽

10.22146/jpti.16618 ◽

2017 ◽

Vol 20 (1) ◽

pp. 7

Author(s):

Kurnia Pratiwi ◽

Y. Andi Trisyono ◽

Edhi Martono

Keyword(s):

Bacillus Thuringiensis ◽

Larval Stage ◽

Spodoptera Litura ◽

Insect Pest ◽

Survival Rates ◽

Pupal Weight ◽

Ostrinia Furnacalis ◽

Corn Borer ◽

Bt Toxin ◽

And Control

ABSTRACTSpodoptera litura is one of the important insect pest of maize besides the notoriously damaging corn borer, Ostrinia furnacalis. S. litura has been the target of various controls including the use of Bacillus thuringiensis (Bt) toxin Cry1A.105 and Cry2Ab2. This study was conducted to evaluate the acute effect of Bt toxin Cry1A.105 and Cry2Ab2 on the growth and development of S. litura from larval to adult stages. Two sublethal concentrations were used; 0.1875 and 0.0469 ppm for Cry1A.105, and 0.0008 and 0.0003 ppm for Cry2Ab2. The bioassay using diet dipping was carried out on a CRD with three experiments and five repetitions. The observation was carried out on the mortality and survival rates of S. litura. The mortality reached 28% when the larvae were treated with 0.1875 ppm and 20% with 0.0469 ppm of Cry 1A.105. The exposed larvae and pupae were smaller than control. Larval and pupal weight were 117.0 and 165.6 g with 0.1875 ppm, while control were 212.9 and 211.2 g. Cry1A.105 also longer the larval stage, larval stage with higher and lower concentration were 24.5 and 22.3 day, while control was 20.5 day. The resulted pupae from larve which exposed by Cry1A.105 were less than control; there were 40% at concentration 0.1875 ppm and control 61%. The two concentration of Cry2Ab2 produced similar mortality of 20%. Similarly, Cry2Ab2 affected pupal to adult stages development. The longevity of pupal stage with concentration 0.0003 ppm was 9.5 days, followed by 0.0008 ppm (9.1 days) and control (10.1 days). The adult emerge on the highest concentration was 47.4% while control only 34.6%. There results showed that both Cry1A.105 and Cry2Ab2 were detrimental to the survival of S. litura which is the non-target insect of transgenic Bt maize.Keywords: Cry1A.105, Cry2Ab2, maize, non-target pest, Spodoptera litura, survival INTISARISpodoptera litura merupakan salah satu hama penting yang menyerang tanaman jagung, selain Ostrinia furnacalis. Belakangan ini O. furnacalis diketahui telah menjadi target dari berbagai macam cara pengendalian termasuk penggunaan toksin Bacillus thuringiensis (Bt) Cry1A.105 dan Cry2Ab2. Penelitian ini dilakukan untuk mengetahui efek akut toksin Bt Cry1A.105 dan Cry2Ab2 terhadap pertumbuhan dan perkembangan S. litura dari larva sampai imago. Dua konsentrasi subletal yang akan digunakan adalah; 0,1875 dan 0,0469 ppm untuk Cry1A.105, dan 0,0008 dan 0,0003 ppm untuk Cry2Ab2. Pengujian dilakukan dengan menggunakan metode celup pakan dan Rancangan Acak Legkap dengan tiga perlakuan dan lima ulangan. Pengamatan dilakukan terhadap mortalitas dan kelangsungan hidup S. litura. Mortalitas mencapai 28% pada larva yang dipaparkan dengan 0,1875 ppm dan 20% dengan 0,0469 ppm Cry 1A.105. Larva dan pupa yang terkena toksin berukuran lebih kecil. Berat larva dan pupa yang terpapar toksin dengan konsentrasi 0,1875 ppm, masing – masing 117,0 dan 165,6 g, sedangkan kontrol masing – masing 212,9 dan 211,2 g. Cry1A.105 juga dapat memperpanjang stadia larva. Lama stadia larva dengan konsentrasi tertinggi dan terendah adalah 24,5 dan 22,3 hari, sedangkan kontrol 20,5 hari. Jumlah pupa yang berhasil terbentuk dari larva yang terpapar toxin Cry1A.105 lebih sedikit dibandingkan dengan kontrol; pada konsentrasi 0,1875 ppm sebesar 40%, sedangkan kontrol sebesar 61%. Kedua konsentrasi dari toksin Bt Cry2Ab2 menyebabkan mortalitas yang sama yaitu 20%. Cry2Ab2 juga berpengaruh terhadap lama stadia pupa dan tingkat keberhasilan pembentukan imago. Lama stadia pupa dengan konsentrasi 0,0003 ppm adalah 9,5 hari, diikuti dengan konsentrasi 0,0008 ppm (9,1 hari) dan kontrol (10,1 hari). Jumlah imago terbanyak terdapat pada perlakuan dengan konsentrasi 0,0008 ppm sebesar 47,4% sedangkan pada kontrol hanya 34,6%. Hal ini menunjukkan bahwa toksin Bt Cry1A. 105 dan Cry2Ab2 juga berpengaruh terhadap kelangsungan hidup S. litura yang merupakan serangga bukan sasaran dari tanaman jagung transgenik Bt.Kata kunci: Cry1A.105, Cry2Ab2, hama bukan sasaran, jagung, kelangsungan hidup, Spodoptera litura

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β-carotene and Bacillus thuringiensis insecticidal protein differentially modulate feeding behaviour, mortality and physiology of European corn borer (Ostrinia nubilalis)

PLoS ONE ◽

10.1371/journal.pone.0246696 ◽

2021 ◽

Vol 16 (2) ◽

pp. e0246696

Author(s):

Patricia Sarai Girón-Calva ◽

Carmen Lopez ◽

Alfonso Albacete ◽

Ramon Albajes ◽

Paul Christou ◽

...

Keyword(s):

Bacillus Thuringiensis ◽

Ostrinia Nubilalis ◽

Feeding Behaviour ◽

European Corn Borer ◽

Insect Pests ◽

Crop Protection ◽

Insecticidal Protein ◽

Pupal Weight ◽

Bt Protein ◽

Β Carotene

Maize with enhanced β-carotene production was engineered to counteract pervasive vitamin A deficiency in developing countries. Second-generation biofortified crops are being developed with additional traits that confer pest resistance. These include crops that can produce Bacillus thuringiensis Berliner (Bt) insecticidal proteins. Currently, it is unknown whether β-carotene can confer fitness benefits through to insect pests, specifically through altering Ostrinia nubilalis foraging behaviour or development in the presence of Bt insecticidal toxin. Therefore the effects of dietary β-carotene plus Bt insecticidal protein on feeding behaviour, mortality, and physiology in early and late instars of O. nubilalis larvae were investigated. The results of two-choice experiments showed that irrespective of β-carotene presence, at day five 68%-90% of neonates and 69%-77% of fifth-instar larvae avoided diets with Cry1A protein. Over 65% of neonate larvae preferred to feed on diets with β-carotene alone compared to 39% of fifth-instar larvae. Higher mortality (65%-97%) in neonates fed diets supplemented with β-carotene alone and in combination with Bt protein was found, whereas <36% mortality was observed when fed diets without supplemented β-carotene or Bt protein. Diets with both β-carotene and Bt protein extended 25 days the larval developmental duration from neonate to fifth instar (compared to Bt diets) but did not impair larval or pupal weight. Juvenile hormone and 20-hydroxyecdysone regulate insect development and their levels were at least 3-fold higher in larvae fed diets with β-carotene for 3 days. Overall, these results suggest that the effects of β-carotene and Bt protein on O. nubilalis is dependent on larval developmental stage. This study is one of the first that provides insight on how the interaction of novel traits may modulate crop susceptibility to insect pests. This understanding will in turn inform the development of crop protection strategies with greater efficacy.

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Fitness Costs of Chlorantraniliprole Resistance Related to the SeNPF Overexpression in the Spodoptera exigua (Lepidoptera: Noctuidae)

International Journal of Molecular Sciences ◽

10.3390/ijms22095027 ◽

2021 ◽

Vol 22 (9) ◽

pp. 5027

Author(s):

Changwei Gong ◽

Xinge Yao ◽

Qunfang Yang ◽

Xuegui Wang ◽

Yuming Zhang ◽

...

Keyword(s):

Insect Pest ◽

Ryanodine Receptors ◽

Oviposition Rate ◽

Fitness Cost ◽

Fitness Costs ◽

Male Adult ◽

Mating Response ◽

Transmembrane Segments ◽

High Level ◽

Lepidoptera Noctuidae

Spodopteraexigua, a multifeeding insect pest, has developed a high level of resistance to chlorantraniliprole, which is a benzoylurea insecticide that targets the ryanodine receptors (RyRs). Herein, the resistant strain (SE-Sel) and sensitive strain (SE-Sus) were obtained by bidirectional screening for six generations. The potential oviposited eggs and oviposition rate of the SE-Sel strain were dramatically lower than those of the SE-Sus strain; on the contrary, the weights of prepupae and preadult were significantly increased. As a post-mating response, the higher number of non-oviposited eggs in the SE-Sel strain was caused by a lower mating rate. In addition, the expression levels of vitellogenin (SeVg) and its receptor (SeVgR) in the SE-Sel strain were consistently lower than those in the SE-Sus strain. An RyRI4743M mutation, contributing to the resistance to chlorantraniliprole, was located in the S3 transmembrane segments and might have affected the release of calcium ions; it led to the upregulated expression of the neuropeptide SeNPF and its receptor SeNPFR, and the mating and oviposition rate were significantly recovered when the SeNPF was knocked down though RNA interference (RNAi) in the male adult of the SE-Sel strain. Moreover, the expression of the juvenile hormone-binding proteins SeJHBWDS3 and SeJHBAN in the male adult of the SE-Sel strain was significantly decreased, which proved the existence of a fitness cost from another angle. Therefore, these results indicate that the fitness cost accompanied by chlorantraniliprole resistance in S. exigua may be related to the decrease in mating desire due to SeNPF overexpression.

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Biological activities of spores and metabolites of some fungal isolates on certain aspects of the spiny bollworms Earias insulana (Boisd.) (Lepidoptera: Noctuidae)

Egyptian Journal of Biological Pest Control ◽

10.1186/s41938-019-0192-y ◽

2019 ◽

Vol 29 (1) ◽

Cited By ~ 1

Author(s):

Eman Mohammed Abd-ElAzeem ◽

Warda Ahmed Zaki El-Medany ◽

Hend Mohammed Sabry

Keyword(s):

Biological Activities ◽

Larval Mortality ◽

Adult Emergence ◽

Pupal Weight ◽

Earias Insulana ◽

Dead Larva ◽

Fungal Isolates ◽

Protease Enzyme ◽

Newly Hatched Larvae ◽

Lepidoptera Noctuidae

AbstractBiological activities of spores and metabolites of some fungi isolated from dead larva of the spiny bollworms (SBW), Earias insulana (Boisd.) (Lepidoptera: Noctuidae), against the newly hatched larvae of the pest were carried out. Results showed that the fungi Metarhizium anisopliae, Acremonium sp., and Paecilomyces variotii had affected the newly hatched larvae of (SBW). Acremonium sp. was the most potent one as it had the highest newly hatched larval mortality percentage (65 and 58.33%) for its spore suspension and metabolites, respectively, while the lowest one (41%) was for P. variotii metabolites. Also, spore suspensions of the all fungal isolates had the highest larval mortality than fungal metabolites. Studying the enzymatic activity showed that Acremonium sp. produced protease enzyme on media containing gelatin, which caused the highest larval mortality (72.22%).These isolates showed different effects on all stages of the pest and decreased pupal weight, adult emergence percentages, deposited eggs, and hatchability percentages than the control. Identification of Acremonium sp. EZ1 was confirmed using 18 s rRNA and its accession number MN25101.

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