Larvae Of Cabbage Moth Research Articles

Synthesis and application of zinc oxide nanoparticles in <i>Pieris brassicae</i> larvae as a possible pesticide effect

<p><italic>Pieris brassicae</italic> is commonly known as the cabbage moth and is a species known to be invasive, thereby causing serious damage to vegetables and subsequently leading to total crop loss. Formulations of nanopesticides can provide unique characteristics such as size and shape, in addition to having integrated properties in a single material, making them efficient in pest management and protection against diseases in a single material; it can be applied in small volumes, with a greater precision, lower input costs, and a potential reduction in environmental contamination. Nanotechnology is a type of alternative and highly effective technology in several sectors, mainly in agriculture and the enrichment and fortification of cultivars. Hydrothermal synthesis is a type of process used to obtain nanoparticles with a more uniform crystallinity and aging of nanocrystallites, where high temperatures and pressures help to reduce particle aggregation. Chemically synthesized metal nanoparticles, such as zinc oxide nanoparticles (ZnO NPs), can find wide applications and success against different types of pests, such as larvae. The present study focuses on the application of different concentrations of ZnO NPs (12.5, 25, 50, 100, 200 and 400 mg/L) on the body surface of <italic>P. brassicae</italic> to verify their possible pesticide activity against these larvae. The results of this study suggest a non-intuitive pesticidal activity of ZnO NPs against cabbage moth larvae. The highest mortality percentage of larvae against the treatments occurred at the concentration of 200 mg/L of ZnO NPs, represented by a rate of 100% in the 72-h period of the experiment. Finally, the results of the present study with ZnO NPs and <italic>P. brassicae</italic> larvae suggest an initial trigger for future possibilities of exploration and more in-depth studies to clarify the interaction of ZnO NPs and the possible metabolic pathways triggered in these insect pests.</p><p><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="molsci-11-04-021-g004.tif"/></p>

Results of testing of the efficacy of sublethal concentrations of bacterial-chemical insecticides combinations against cabbage moth larvae

Using chemical pesticides has adverse effects on the environment and humans. Bacterial preparations may provide an alternative to chemical pesticides. The study aims to test different combinations of sublethal concentrations of bacterial and chemical preparations against cabbage moth larvae. During 2020-2022 different combinations of sublethal concentrations of bacterial (Lepidocide) and chemical (Arrivo, Voliam Flexi, Proclaim Fit) preparations were tested in laboratory and field conditions, against cabbage moth young larvae (stage I-II). The combinations of insecticides with bacterial and chemical sublethal concentrations show high biological efficiency against the cabbage moth larvae. No statistical difference was found between the efficiency indicators of the combined and standard chemical (Arrivo, Voliam Flexi, Proclaim Fit) options and the significance level was generally between 2.0 and 5.9 %, showing that the results of the scientific experiments are reliable.

Susceptibility of different species of lepidoptera insects to strain Bacillus thuringiensis ssp. aizawai

The results of assessing the effect of Bacillus thuringiensis ssp. aizawai strain on fi ve species of lepidopteran pests (Lepidoptera) belonging to different families are presented. The mortality of larvae infected with B. thuringiensis strain varied signifi cantly depending on the species of insect. In four species: the cabbage white butterfl y (Pieris brassicae L.), the cabbage moth (Mamestra brassicae L.), the greater wax moth (Galleria melonella L.) and the black-veined white (Aporia crataegi L.), death of individuals was noted on the second day of the experiment. However, mortality rate was signifi cantly different between species and increased over time. The diamondback moth (Plutella xylostella L.) was more susceptible to the pathogen. Signifi cant mortality of the larvae of this phytophage was observed already on the fi rst day after infection; while on the second day of the experiment all individuals died. Lethal time LT90 of more resistant species (black-veined white) and more sensitive ones (diamondback moth) differed sevenfold. Semi-lethal concentrations of B. thuringiensis strain for the tested insect species were determined: on the third day of the experiment, lethal concentration LC50 for the cabbage moth larvae, the greater wax moth and blackveined white ranged from 1.7 to 4.5 × 108 spores/ ml. For the cabbage white butterfl y, it was much lower (1.8×107 spores/ml). For diamondback moth caterpillars, LC50 was 4.25×107 spores/ml already one day after infection. It was noted that the specifi city of B. thuringiensis strain is associated with various mechanisms of insect protection from pathogens, and is due to individual characteristics of the species. In particular, the pH of excrement of intact caterpillars of the cabbage white butterfl y, a species sensitive to B. thuringiensis, was 2 times higher than that of caterpillars of the greater wax moth – 8.9 and 4.3, respectively, which is one of the reasons for the susceptibility (or resistance) of the species to bacterial entomopathogen.

A recombinant fusion protein containing a spider toxin specific for the insect voltage-gated sodium ion channel shows oral toxicity towards insects of different orders

Recombinant fusion protein technology allows specific insecticidal protein and peptide toxins to display activity in orally-delivered biopesticides. The spider venom peptide δ-amaurobitoxin-PI1a, which targets insect voltage-gated sodium channels, was fused to the “carrier” snowdrop lectin (GNA) to confer oral toxicity.The toxin itself (PI1a) and an amaurobitoxin/GNA fusion protein (PI1a/GNA) were produced using the yeast Pichia pastoris as expression host. Although both proteins caused mortality when injected into cabbage moth (Mamestra brassicae) larvae, the PI1a/GNA fusion was approximately 6 times as effective as recombinant PI1a on a molar basis. PI1a alone was not orally active against cabbage moth larvae, but a single 30 μg dose of the PI1a/GNA fusion protein caused 100% larval mortality within 6 days when fed to 3rd instar larvae, and caused significant reductions in survival, growth and feeding in 4th – 6th instar larvae. Transport of fusion protein from gut contents to the haemolymph of cabbage moth larvae, and binding to the nerve chord, was shown by Western blotting. The PI1a/GNA fusion protein also caused mortality when delivered orally to dipteran (Musca domestica; housefly) and hemipteran (Acyrthosiphon pisum; pea aphid) insects, making it a promising candidate for development as a biopesticide.

An evaluation of garlic lectin as an alternative carrier domain for insecticidal fusion proteins

AbstractThe mannose‐binding lectin GNA (snowdrop lectin) is used as a “carrier” domain in insecticidal fusion proteins which cross the insect gut after oral ingestion. A similar lectin from garlic bulb, ASAII, has been evaluated as an alternative “carrier”. Recombinant ASAII delivered orally to larvae of cabbage moth (Mamestra brassica; Lepidoptera) was subsequently detected in haemolymph, demonstrating transport. Fusion proteins comprising an insect neurotoxin, ButaIT (Buthus tamulus insecticidal toxin; red scorpion toxin) linked to the C‐terminal region of ASAII or GNA were produced as recombinant proteins (GNA/ButaIT and ASA/ButaIT) by expression in Pichia pastoris. In both cases the C‐terminal sequence of the lectin was truncated to avoid post‐translational proteolysis. The GNA‐containing fusion protein was toxic by injection to cabbage moth larvae (LD50≈ 250 μg/g), and when fed had a negative effect on survival and growth. It also decreased the survival of cereal aphids (Sitobion avenae; Homoptera) from neonate to adult by >70% when fed. In contrast, the ASA‐ButaIT fusion protein was non‐toxic to aphids, and had no effect on lepidopteran larvae, either when injected or when fed. However, intact ASA‐ButaIT fusion protein was present in the haemolymph of cabbage moth larvae following ingestion, showing that transport of the fusion had occurred. The stabilities of GNA/ButaIT and ASA/ButaIT to proteolysis in vivo after injection or ingestion differed, and this may be a factor in determining insecticidal activities.

Evaluation of Effect of PxGV-Taiwanii on Cabbage moth Plutella xylostella (Lep.: Plutellidae) in Laboratory Conditions

The effect of one entomopathogenic virus (PxGV) was studied on cabbage moth Plutella xylostella with hope to find management strategies of this insect, based on biological control. Bioassay showed that, this virus has high virulence and can be considered as the important agents on the control of this insect. The LC50 value of PxGV for second instar larvae of cabbage moth was calculated 448.58 g mm(-2). The LT50 values for the same larvae with 749.89 and 1883.65 g mm(-2) doses of PxGV were 6.04 and 6.85 days, respectively.

The genome of the lepidopteran Mamestra brassicae has a vertebrate-like content of methyl-cytosine.

Mamestra brassicae genomic DNAs, isolated from larvae and adult tissues and from in vitro cultured CRL-8003 cells, were enzymatically hydrolysed to nucleosides that were separated by HPLC. HPLC analysis showed that 5mC content in cabbage moth larvae, adults and cultured cells was 8.9 +/- 0.5, 9.3% +/- 0.2 and 10.2% +/- 0.4 respectively. Cabbage moth 5mC content results the highest reported till now in insects and it is similar to the typical vertebrate one. Analysis of MspI and HpaII restriction pattern on M. brassicae DNA showed that a portion of its genome was methylated at CpG sites. Moreover, the absence of small digestion products after MspI digestion suggested that CpG are not clustered in the cabbage moth genome. Finally, methylation of repeated DNAs has been studied. Comparison of the restriction pattern of MspI and HpaII after hybridisation with the hobo, mariner, 28S and 5S rDNA probes did not evidence any difference indicating the absence of CpG methylation in all the studied repeated DNAs.

Dose-Response Tests with Neem Azal-T Against the Cabbage Moth, 1995

Abstract Cabbage plants in pots were inverted and dipped in 1.5 liters of a solution of Neem Azal-T (Trifolio-M GmbH, Germany). Neem Azal-T contains 5% azadirachtin, generally considered the active ingredient in neem extracts. Neem Azal-T was diluted in water at concentrations of 0, 0.25, 0.5, 1, 2, 4, 8 and 16 ppm azadirachtin. Each plant was held in the solution for 60 sees. After dipping, the plants were set in a screened insectary to dry for 3 hours, cabbage moth larvae in the early 2nd instar were placed in net bags, 20 larvae per bag, and the bags were placed over each plant and secured at the base of the stem. The plants were arranged on the concrete insectary floor in a RCB design with 5 replications. The average air temperature during the experiment was 15.5°C. The average day length was 18 h. The experiment lasted 16 days, at which time larval mortality was assessed.