scholarly journals Differential side-effects of Bacillus thuringiensis bioinsecticide on non-target Drosophila flies

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Aurélie Babin ◽  
Marie-Paule Nawrot-Esposito ◽  
Armel Gallet ◽  
Jean-Luc Gatti ◽  
Marylène Poirié
Keyword(s):  
Side Effects ◽  
Bacillus Thuringiensis ◽  
Insect Pests ◽  
Larval Mortality ◽  
Specific Effect ◽  
Adult Emergence ◽  
Developmental Time ◽  
Field Application ◽  
Dependent Manner ◽  
Offspring Number

Abstract Bioinsecticides based on Bacillus thuringiensis (Bt) spores and toxins are increasingly popular alternative solutions to control insect pests, with potential impact of their accumulation in the environment on non-target organisms. Here, we tested the effects of chronic exposure to commercial Bt formulations (Bt var. kurstaki and israelensis) on eight non-target Drosophila species present in Bt-treated areas, including D. melanogaster (four strains). Doses up to those recommended for field application (~ 106 Colony Forming Unit (CFU)/g fly medium) did not impact fly development, while no fly emerged at ≥ 1000-fold this dose. Doses between 10- to 100-fold the recommended one increased developmental time and decreased adult emergence rates in a dose-dependent manner, with species-and strain-specific effect amplitudes. Focusing on D. melanogaster, development alterations were due to instar-dependent larval mortality, and the longevity and offspring number of adult flies exposed to bioinsecticide throughout their development were moderately influenced. Our data also suggest a synergy between the formulation compounds (spores, cleaved toxins, additives) might induce the bioinsecticide effects on larval development. Although recommended doses had no impact on non-target Drosophila species, misuse or local environmental accumulation of Bt bioinsecticides could have side-effects on fly populations with potential implications for their associated communities.

scholarly journals Differential side-effects ofBacillus thuringiensisbioinsecticide on non-targetDrosophilaflies

2019 ◽  
Author(s):  
Aurélie Babin ◽  
Marie-Paule Nawrot-Esposito ◽  
Armel Gallet ◽  
Jean-Luc Gatti ◽  
Marylène Poirié
Keyword(s):  
Side Effects ◽  
Chronic Exposure ◽  
Insect Pests ◽  
Larval Mortality ◽  
Adult Emergence ◽  
Developmental Time ◽  
Field Application ◽  
Dependent Manner ◽  
Dose Dependent ◽  
Control Insect

AbstractBiopesticides based onBacillus thuringiensis(Bt) spores and toxins are alternate pest management solutions widely used to control insect pests. Their increasing use could lead to accumulation in the environment, hence leading to chronic exposure of non-target organisms. Here, we tested for potential non-intentional side-effects of chronic exposure toBtbiopesticide on larvae of non-targetDrosophilaspecies present inBt-treated areas. Doses up to those recommended for field application (106CFU/g of fly medium) had no effect on the fly development, whereas doses 10 to 100-fold higher (107-108CFU/g) increased developmental time and decreased adult emergence rates in a dose-dependent manner and with varying effect amplitudes for all the species and strains tested. For all them, all larvae died before pupation at the highest dose tested (109CFU/g). Focusing onD. melanogaster, delayed development and reduced emergence resulted from stage-dependent larval mortality, and fitness-related traits of adult flies emerging from survivingBtbiopesticide exposure were moderately increased. The effects ofBtbiopesticide seemed to result from the spores/cleaved toxins synergy, and possibly additives. While recommended doses had no effect on non-targetDrosophilaspecies, misuse or local accumulation ofBtbioinsecticides in the environment could have non-intentional side-effects on fly populations with potential implications for their associated communities.

Population fluctuations of the African armyworm, Spodoptera exempta (Walker) (Lepidoptera: Noctuidae), in Outdoor Cages in Kenya

1981 ◽  
Vol 71 (2) ◽  
pp. 289-297 ◽  
Author(s):  
B. Persson
Keyword(s):  
Cynodon Dactylon ◽  
Lake Victoria ◽  
Larval Mortality ◽  
Adult Emergence ◽  
Developmental Time ◽  
Egg Laying ◽  
Spodoptera Exempta ◽  
Population Fluctuations ◽  
One Year ◽  
Nuclear Polyhedrosis

AbstractSpodoptera exempta (Wlk.) was reared for one year at three locations in Kenya: Msabaha on the coast, Nairobi, and Mbita Point on Lake Victoria. The potential yearly number of generations was 15·8 at Msabaha, 6·6 at Nairobi and 13·1 at Mbita Point. Average developmental time from egg deposition to adult emergence was 23·1, 54·9 and 27·8 days, respectively. The longest, 77·3 days, was recorded in Nairobi and the shortest, 19·4 days, at Msabaha. The survival rate varied little seasonally at the coast but was erratic inland, with some generations failing and others very successful. Larvae offered a choice of maize and stargrass (Cynodon dactylon) showed a preference for stargrass. Survival was higher on stargrass than on maize but the developmental time was longer. Mortality was highest in the larval stage. In all generations and at all locations, death was usually caused by a nuclear polyhedrosis virus. There was a positive relationship between larval mortality and rainfall, and a negative one between larval mortality and sunshine. Mating was restricted to after midnight. Females oviposited and then mated during the same night. Peak egg-laying took place before midnight, with a smaller peak at about 02·00–04·00 h.

scholarly journals Efficacy of Metarhizium anisopliae and Bacillus thuringiensis against tomato leafminer Tuta absoluta Meyrick (Lepidoptera: Gelechiidae)

2019 ◽  
Vol 7 (1) ◽  
pp. 37-45 ◽  
Author(s):  
Spyridon Mantzoukas ◽  
Nikoleta-Kleio Denaxa ◽  
Ioannis Lagogiannis
Keyword(s):  
Single Dose ◽  
Bacillus Thuringiensis ◽  
Dose Rate ◽  
Entomopathogenic Fungi ◽  
Metarhizium Anisopliae ◽  
Larval Mortality ◽  
Adult Emergence ◽  
Biocontrol Agents ◽  
Tuta Absoluta ◽  
Combined Application

Susceptibility of Tuta absoluta Meyrick (Lepidoptera: Gelechiidae) populations to Metarhizium anisopliae and Bacillus thuringiensis (Bt) were evaluated under laboratory conditions. T. absoluta larvae were treated either individually or in combination with a single dose rate of B. thuringiensis (0.5 μL/L) and three conidial suspensions viz. 1x104, 1x106 and 1x108 spores/mL of M. anisopliae. Larval mortality, pupation, adult emergence, mycosis and sporulation varied depending on the application of different quantities of M. anisopliae alone and in combination with B. thuringiensis. Maximum mortality (100%) was achieved in 2nd instar larvae when M. anisopliae (1x108 spores/mL) and B. thuringiensis (0.5µL/L) were applied synergistically,while 4th instar larvae recorded a 95.45% mortality. Compared with the untreated checks, mortality, pupation and adult emergence of both 2nd and 4th instar larvae were significantly reduced with the combined application of M. anisopliae (1x108 spores/mL) and B. thuringiensis (0.5µL/L). Μycosis was most prevalent on 2nd and 4th instar larvae, exceeding 88 and 80% respectively,after exposure to 1×104 conidia/mL. The results indicate that the entomopathogenic fungi and the insecticidal protein produced by B. thuringiensis can be used in combination as biocontrol agents for the management of T. absoluta.

scholarly journals Effectivity of Bacillus thuringiensis from Soil in Freshwater Swamps against Epilachna sp. Larvae

2021 ◽  
Vol 10 (1) ◽  
pp. 46-53
Author(s):  
Yulia Pujiastuti ◽  
Erni Indriani ◽  
A Muslim ◽  
Chandra Irsan ◽  
Arsi Arsi
Keyword(s):  
Bacillus Thuringiensis ◽  
Protein Content ◽  
Insect Pests ◽  
Larval Mortality ◽  
Test Results ◽  
Solanum Torvum ◽  
Insecticide Treatment ◽  
Randomized Design ◽  
Freshwater Swamp ◽  
Completely Randomized Design

Bacillus thuringiensis is an entomopathogenic bacterium isolated from the soil and  has been widely used as an active ingredient in the manufacture of bioinsecticides. The target insects are very specific and depend on the type of protein content. Epilachna sp. are important insect pests because both larvae and adults as plant-eating pests. The research aimed was to investigate the effectivity  of  B. thuringiensis against the larvae of Epilachna sp.. B. thuringiensis- bio-insecticide was prepared using isolates originally from freshwater swamp soil of South Sumatra (SMR04). Epilachna sp larvae were mass-reared with Solanum torvum leaf feed in the laboratory. The design used was a completely randomized design, with 6 treatments and 5 replications. Treatments were spore concentration contained in the bioinsecticide solution included: 1 x 108, 1 x 107, 1 x 106, 1 x 105 spores/mL, commercial bio-insecticide and without treatment as a control. Each replication used 10 individual of the 2nd larvae. Statistical test results showed larval mortality in B. thuringiensis treatment was significantly different from commercial bio-insecticide treatment. The highest mortality of bio-insecticide treatment occurred at a concentration of 108 spores/ml (40.00 %) and the lowest was at a concentration of 105 spores/mL (18.01 %). The lowest LT50 value of bio-insecticide treatment was at a concentration of 108 spores/mL, namely 79.37 hours. The control of larvae included in the Coleoptera order was still not satisfactory yet, considering the presence of protein content in B. thuringiensis strain SMR04 which did not match the type of protein required.

scholarly journals Effects of larval diet on the life-history traits and phenotypic expression of pyrethroid resistance in the major malaria vector Anopheles gambiae s.s.

2022 ◽  
Author(s):  
Pierre Marie Sovegnon ◽  
Marie Joelle Fanou ◽  
Romaric Akoton ◽  
Oswald Yédjinnavênan Djihinto ◽  
Hamirath Odée Lagnika ◽  
...  
Keyword(s):  
Life History ◽  
Insecticide Resistance ◽  
Life History Traits ◽  
Wing Length ◽  
Larval Mortality ◽  
Adult Emergence ◽  
Developmental Time ◽  
Larval Diet ◽  
Anopheles Gambiae S.S ◽  
Permanet 3.0

The success achieved in reducing malaria transmission by vector control is threatened by insecticide resistance. To strengthen the current vector control programmes, the non-genetic factors underlying the emergence of insecticide resistance in Anopheles vectors and its widespread need to be explored. This study aimed to assess the effects of larval diet on some life-history traits and pyrethroid-insecticide susceptibility of Anopheles gambiae s.s. Three (3) An. gambiae strains, namely Kisumu (insecticide susceptible), AcerKis (homozygous ace-1 R G119S resistant) and KisKdr (homozygous kdr R L1014F resistant) were fed with three different diets (low, medium, and high) of TetraMin ® Baby fish food. Pre-imaginal developmental time, larval mortality, adult emergence rate and female wing length were measured. Mosquito females were exposed to insecticide-treated net (ITN) PermaNet 2.0 and PermaNet 3.0. In the three An. gambiae strains, significant differences in adult emergence rates ( F = 1054.2; df = 2; p <0.01), mosquito wing length ( F = 970.5; df = 2; p <0.01) and adult survival post insecticide exposure ( χ2 = 173; df = 2; p <0.01), were noticed among the three larval diets. Larvae fed with the low food diets took more time to develop, were smaller at emergence and displayed a short lifespan, while the specimens fed with a high regime developed faster and into big adults. Although being fed with a high diet, none of An. gambiae strain harbouring the kdr R and ace-1 R allele survived 24 hours after exposure against PermaNet 3.0. This study showed that variation in the larval diet significantly impacts An. gambiae life-history traits such as larval mortality and developmental time, adult wing length, and female susceptibility to pyrethroid insecticides. Further investigations through field-based studies would allow an in-depth understanding of the implications of these non-genetic parameters on the physiological traits of malaria vectors and consequently improve resistance management.

scholarly journals Iflavirus Covert Infection Increases Susceptibility to Nucleopolyhedrovirus Disease in Spodoptera exigua

Viruses ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 509
Author(s):  
Arkaitz Carballo ◽  
Trevor Williams ◽  
Rosa Murillo ◽  
Primitivo Caballero
Keyword(s):  
Spodoptera Exigua ◽  
Developmental Stages ◽  
Larval Mortality ◽  
Adult Emergence ◽  
Developmental Time ◽  
Pupal Weight ◽  
Biological Pest Control ◽  
Egg Masses ◽  
Time To Death ◽  
Covert Infection

Naturally occurring covert infections in lepidopteran populations can involve multiple viruses with potentially different transmission strategies. In this study, we characterized covert infection by two RNA viruses, Spodoptera exigua iflavirus 1 (SeIV-1) and Spodoptera exigua iflavirus 2 (SeIV-2) (family Iflaviridae) that naturally infect populations of Spodoptera exigua, and examined their influence on susceptibility to patent disease by the nucleopolyhedrovirus Spodoptera exigua multiple nucleopolyhedrovirus (SeMNPV) (family Baculoviridae). The abundance of SeIV-1 genomes increased up to ten-thousand-fold across insect developmental stages after surface contamination of host eggs with a mixture of SeIV-1 and SeIV-2 particles, whereas the abundance of SeIV-2 remained constant across all developmental stages. Low levels of SeIV-2 infection were detected in all groups of insects, including those that hatched from surface-decontaminated egg masses. SeIV-1 infection resulted in reduced larval weight gain, and an unbalanced sex ratio, whereas larval developmental time, pupal weight, and adult emergence and fecundity were not significantly affected in infected adults. The inoculation of S. exigua egg masses with iflavirus, followed by a subsequent infection with SeMNPV, resulted in an additive effect on larval mortality. The 50% lethal concentration (LC50) of SeMNPV was reduced nearly 4-fold and the mean time to death was faster by 12 h in iflavirus-treated insects. These results suggest that inapparent iflavirus infections may be able to modulate the host response to a new pathogen, a finding that has particular relevance to the use of SeMNPV as the basis for biological pest control products.

scholarly journals Evaluation of indigenous the nucleopolyhedrovirus (NPV) of Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae) in combination with chlorantraniliprole against Spodoptera species

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Ghulam Sarwar ◽  
Naeem Arshad Maan ◽  
Muhammad Ahsin Ayub ◽  
Muhammad Rafiq Shahid ◽  
Mubasher Ahmad Malik ◽  
...  
Keyword(s):  
Larval Mortality ◽  
Adult Emergence ◽  
Lethal Concentration ◽  
Pest Species ◽  
Vegetable Crops ◽  
Chemical Insecticide ◽  
Larval Instars ◽  
Novel Method ◽  
High Larval Mortality ◽  
Lepidoptera Noctuidae

Abstract Background The armyworms, Spodoptera exigua (Hübner), and S. litura (Fabricius) (Lepidoptera: Noctuidae) are polyphagous pests of many cash crops. Heavy crop losses have been reported for the fruit and vegetable crops each year owing to the diverse impact on global economies. The present study was aimed to sort out a novel method of pest control using the insect’s own nucleopolyhedrosis virus (NPV) alone and in combination with a new chemistry insecticide chlorantraniliprole. Results In the study, the effect of indigenous isolated nucleopolyhedrovirus (NPV) and the chemical insecticide (chlorantraniliprole) formulations against the 2nd and 4th larval instars of S. litura and S. exigua, collected from the different geographical region of Punjab (Pakistan) province, was evaluated. Three concentrations of the NPV isolate, sub-lethal (1 × 104, 6 × 104 POB ml−1), lethal (3 × 105 POB ml−1), and chlorantraniliprole 0.01 μl l−1, were applied alone and in combination against the 2nd and 4th larval instars of both pest species. The lethal concentration of NPV + chlorantraniliprole exhibited synergistic interaction and caused high larval mortality against both instars, while in all other combinations, additive effect was observed. Moreover, NPV + chlorantraniliprole at lethal concentration exhibited decreased pupation, adult emergence, and egg eclosion. Conclusion The implications of using NPV alone and in combination with an insecticide are discussed briefly in this study.

scholarly journals Mechanisms contributing to ado-trastuzumab emtansine (T-DM1)-induced toxicities: a gateway to better understanding ADC-associated toxicities

2021 ◽  
Author(s):  
Yukinori Endo ◽  
Nishant Mohan ◽  
Milos Dokmanovic ◽  
Wen Jin Wu
Keyword(s):  
Breast Cancer ◽  
Side Effects ◽  
Metastatic Breast ◽  
Invasive Disease ◽  
Dependent Manner ◽  
Trastuzumab Emtansine ◽  
Antibody Drug Conjugate ◽  
Her2 Positive ◽  
Humanized Monoclonal Antibody ◽  
Significant Efficacy

Abstract In order to improve the safety of novel therapeutic drugs, better understanding of the mechanisms of action is important. Ado-trastuzumab emtansine (also known as T-DM1) is an antibody-drug conjugate (ADC) consisting of a humanized monoclonal antibody directed against HER2 (trastuzumab) and a maytansinoid-derived toxin (DM1), which are linked by a non-cleavable thioether linker. T-DM1 has been approved for the treatment of trastuzumab-resistant HER2-positive metastatic breast cancer and recently for use as an adjuvant treatment option for patients with HER2-positive early breast cancer who have residual invasive disease. While the treatment with T-DM1 results in significant efficacy in the selected patient population, nonetheless, there are also concerns with the side effects such as thrombocytopenia and hepatotoxicity. While current understanding of the mechanism of T-DM1-mediated side effects is still incomplete, there have been several reports of HER2-dependent and/or -independent mechanisms that could be associated with the T-DM1-induced adverse events. The results from our laboratory show that T-DM1 binds to cytoskeleton-associated protein 5 (CKAP5) on the cell surface of hepatocytes via its payload component (DM1). This interaction is independent of HER2 and leads to cell growth inhibition and apoptosis of hepatocytes in a T-DM1 dose dependent manner. This review highlights the importance of HER2-independent mechanism of T-DM1 to induce hepatotoxicity, which offers a new insight into a role for CKAP5 in the overall maytansinoid-based ADC (DM1 and DM4)-mediated cytotoxicity. This discovery provides a molecular basis for T-DM1-induced off-target toxicity and opens a new avenue for developing the next generation of ADCs.

scholarly journals Effect of gallic acid on the larvae of Spodoptera litura and its parasitoid Bracon hebetor

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Abhay Punia ◽  
Nalini Singh Chauhan ◽  
Drishtant Singh ◽  
Anup Kumar Kesavan ◽  
Sanehdeep Kaur ◽  
...  
Keyword(s):  
Gallic Acid ◽  
Spodoptera Litura ◽  
Negative Impact ◽  
Larval Mortality ◽  
Adult Emergence ◽  
Egg Hatching ◽  
Bracon Hebetor ◽  
Total Hemocyte Count ◽  
Glutathione S Transferases ◽  
Immense Potential

AbstractThe antibiosis effect of gallic acid on Spodoptera litura F. (Lepidoptera: Noctuidae) and its parasitoid evaluated by feeding six days old larvae on artificial diet incorporated with different concentrations (5 ppm, 25 ppm, 125 ppm, 625 ppm, 3125 ppm) of the phenolic compound revealed higher concentration (LC50) of gallic acid had a negative impact on the survival and physiology of S. litura and its parasitoid Bracon hebetor (Say) (Hymenoptera:Braconidae). The mortality of S. litura larvae was increased whereas adult emergence declined with increasing concentration of gallic acid. The developmental period was delayed significantly and all the nutritional indices were reduced significantly with increase in concentration. Higher concentration (LC50) of gallic acid adversely affected egg hatching, larval mortality, adult emergence and total development period of B. hebetor. At lower concentration (LC30) the effect on B. hebetor adults and larvae was non-significant with respect to control. Gene expression for the enzymes viz., Superoxide dismutase, Glutathione peroxidase, Peroxidase, Esterases and Glutathione S transferases increased while the total hemocyte count of S. litura larvae decreased with treatment. Our findings suggest that gallic acid even at lower concentration (LC30) can impair the growth of S. litura larvae without causing any significant harm to its parasitoid B. hebetor and has immense potential to be used as biopesticides.

scholarly journals Impact of conventional insecticides on two bollworms and their indirect effects on the ectoparasitoid, Bracon brevicornis (Wesmael) (Hymenoptera: Braconidae)

2019 ◽  
Vol 43 (1) ◽  
Author(s):  
Mervat A. Kandil ◽  
Hemat Z. Moustafa
Keyword(s):  
Indirect Effects ◽  
Larval Mortality ◽  
Adult Emergence ◽  
Immature Stage ◽  
Pectinophora Gossypiella ◽  
Earias Insulana ◽  
Pupal Development ◽  
Percentage Mortality ◽  
Biological Aspects ◽  
Newly Hatched Larvae

Abstract Background Cotton bollworms such as Pectinophora gossypiella and Earias insulana are serious pests which destroy the cotton plant, and Bracon brevicornis is a parasitoid which attacked the larvae of bollworms. Results In this study, experiments were performed to investigate and evaluate the toxicity of etofenprox and chlorpyrifos insecticides against newly hatched larvae of Pectinophora gossypiella and Earias insulana. Some biological aspects of compound effects on larval and pupal duration, percentage of mortality, and percentage of adult emergence which resulted from treated newly hatched larvae were studied. The results revealed that LC50 was 0.7 and 0.87 ppm when P. gossypiella was treated with etofenprox and chlorpyrifos, respectively, while LC50 was 0.09 and 0.73 ppm when E. insulana was treated with etofenprox and chlorpyrifos, respectively. The obtained results showed that the percentage of mean larval mortality was 65.0 and 63.0% for treated P. gossypiella, while it was 71.0 and 66.0% for treated E. insulana. The corresponding figure for pupal percentage mortality was 8.0 and 10.0% for treated P. gossypiella, but it was 5.0 and 2.0% for treated E. insulana, with etofenprox and chlorpyrifos, and a prolongation effect in larval and pupal development (total immature stage) resulted from treated both bollworms as follows: 35.5 and 32.4 days for treated P. gossypiella compared with 21.9 days in control and 34.7 and 23.2 days for treated E. insulana compared with 23.1 days in control. The indirect effect of etofenprox and chlorpyrifos on the total immature stage of Bracon brevicornis was 18.2 and 19.5 days compared with 14.3 days in control when B. brevicornis parasitized on P. gossypiella larvae while it was 19.8 and 20.6 days compared with 15.2 days when B. brevicornis parasitized on E. insulana larvae. Conclusion The life cycle of B. brevicornis after parasitism on P. gossypiella and E. insulana larvae treated with etofenprox and chlorpyrifos were increased than the control larvae.

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