scholarly journals Toxicity of isolated phenolic compounds from Acorus calamus L. to control Spodoptera litura (Lepidoptera: Noctuidae) under laboratory conditions

2022 ◽  
Vol 9 (1) ◽  
Author(s):  
Phatcharaphon Wiwattanawanichakun ◽  
Siriwan Saehlee ◽  
Thitaree Yooboon ◽  
Nutchaya Kumrungsee ◽  
Saksit Nobsathian ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Crude Extract ◽  
Spodoptera Litura ◽  
Acorus Calamus ◽  
Botanical Pesticides ◽  
Laboratory Conditions ◽  
Tobacco Cutworm ◽  
Insecticidal Efficacy ◽  
Chemical Pesticides ◽  
Lepidoptera Noctuidae

Abstract Background Spodoptera litura (Lepidoptera: Noctuidae), the tobacco cutworm, is an prominent agricultural pest. To reduce the use of chemical pesticides that cause health problems and that leave residue in the environment, some botanical pesticides have been developed. Our research aimed to evaluate the insecticidal efficacy of Acorus calamus L. extract for the control of S. litura under laboratory conditions. Results After 24 h of topical application, the A. calamus methanolic crude extract showed toxicity against secondary instar S. litura larvae (LD50 ~ 7.438 µg/larva). Chrysin (5,7-dihydroxy flavone), one of the isolated phenolic compounds, showed optimal control efficiency (LD50 ~ 2.752 µg/larva) and showed a reduction in carboxylesterase activities, which have detoxification reduction roles in larvae. Conclusion Chrysin in the crude extract of A. calamus may be an active compound to control this pest, and it may be applied as an alternative to minimize the usage of chemical insecticides. Graphical Abstract

scholarly journals Pathogenicity of Metarhizium rileyi (Farlow) Kepler, S.A. Rehner and Humber isolates against Spodoptera litura (Fabricius) and their extracellular enzymatic activities

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Gurmehar Kaur Grewal ◽  
Neelam Joshi ◽  
Yadhu Suneja
Keyword(s):  
Spodoptera Litura ◽  
Larval Mortality ◽  
Screening Methods ◽  
Metarhizium Rileyi ◽  
Percent Mortality ◽  
Commercially Important ◽  
Extracellular Enzymatic Activities ◽  
Chemical Pesticides ◽  
Lepidoptera Noctuidae

Abstract Background Spodoptera litura (Fab.) (Lepidoptera: Noctuidae) is a serious agricultural pest that infests many commercially important crops of Southeast Asian countries. Indiscriminate use of chemical pesticides has led to various health hazards as well as insecticide resistance. Entomopathogenic fungi (EPF) provide an important alternative as biological control agents. Metarhizium rileyi is an EPF with a specific host range for lepidopteran pests. The present study aimed to identify virulent M. rileyi isolate against S. litura larvae and analyse their extracellular cuticle-degrading enzyme activities. Results Three M. rileyi isolates viz M. rileyi NIPHM, M. rileyi MTCC 4254 and M. rileyi MTCC 10395 formulations were evaluated at different concentrations against 2nd instar larvae of S. litura. A maximum percent mortality of 63.33% was recorded in M. rileyi NIPHM (12 g/l), followed by M. rileyi MTCC 4254 (58.33%) at the same concentration, 10 days post-treatment. Maximum means of chitinase, protease and lipase activities (0.44, 1.58 and 2.95 U/ml, respectively) were recorded in the case of M. rileyi NIPHM. Correlation analysis was positive between enzyme activity and larval mortality. Conclusions Metarhizium rileyi NIPHM recorded the highest enzymatic activity and exhibited the maximum mortality rate against 2nd instar larvae of S. litura, suggesting the possible role of these enzymes in the pathogenicity of the fungus. Further knowledge in this regard may help in the development of enzyme-based screening methods for selecting virulent fungal isolates for the eco-friendly management of crop pests.

Effects of sublethal doses of chlorfluazuron on the biochemical constituents of eggs of Spodoptera litura (Lepidoptera: Noctuidae)

2011 ◽  
Vol 143 (2) ◽  
pp. 178-184
Author(s):  
F. Perveen
Keyword(s):  
Embryonic Development ◽  
Spodoptera Litura ◽  
Treated Male ◽  
Biochemical Constituents ◽  
Tobacco Cutworm ◽  
Sublethal Doses ◽  
Lepidoptera Noctuidae

AbstractThe effects of sublethal doses (LD10: 1.00 ng/larva; LD30: 3.75 ng/larva) of chlorfluazuron on the biochemical constituents of eggs of the tobacco cutworm, Spodoptera litura (F.), are described. Chlorfluazuron was applied topically to fifth-instar larvae and the subsequent adults were allowed to mate according to larval treatment (LD10-treated female × LD10-treated male and LD30-treated female × LD30-treated male). Biochemical constituents of eggs resulting from these pairings were analyzed at various stages of embryonic development. Compared with controls, LD10 or LD30 reduced egg constituents as follows: protein (min.–max.) by 32.8%–34.5% or 62.0%–67.3%, lipid by 33%–34% or 62%–67%, carbohydrates by 30%–39% or 60%–67%, DNA by 33%–40% or 60%–69%, RNA by 31%–34% or 59%–67%, and ecdysteroid by 22%–83% or 28%–92%, respectively. The relative proportions of constituents in control eggs were as follows: protein > lipid > carbohydrate, and RNA > DNA. Three low and three high peaks in ecdysteroid titres were observed. Compared with controls, all peaks were reduced in LD10 or LD30 eggs as follows: low peaks: 1st (at 8 h): 32% or 66%; 2nd (at 16 h): 33% or 67%; 3rd (at 52 h): 35% or 65%; high peaks: 1st (at 32 h): 83% or 92%; 2nd (at 64 h): 65% or 82%; 3rd (at 84 h): 84 h, 36% or 63%, respectively. In addition, the first two high peaks were delayed by 4 h in LD10 eggs and by 8 h in LD30 eggs compared with controls. Sublethal doses of chlorfluazuron reduced the amounts of biochemical constituents of eggs during embryogenesis in S. litura.

scholarly journals Efficacy of Precocene I from Desmosstachya bipinnata as an Effective Bioactive Molecules against the Spodoptera litura Fab. and Its Impact on Eisenia fetida Savigny

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6384
Author(s):  
Narayanan Shyam Sundar ◽  
Sengodan Karthi ◽  
Haridoss Sivanesh ◽  
Vethamonickam Stanley-Raja ◽  
Kanagaraj Muthu-Pandian Chanthini ◽  
...  
Keyword(s):  
Eisenia Fetida ◽  
Spodoptera Litura ◽  
Feeding Activity ◽  
Perennial Grass ◽  
Bioactive Compound ◽  
Bioactive Molecules ◽  
Highly Active ◽  
Nmr Techniques ◽  
Chemical Pesticides ◽  
Lepidoptera Noctuidae

The sustainability of agroecosystems are maintained with agro-chemicals. However, after more than 80 years of intensive use, many pests and pathogens have developed resistance to the currently used chemistries. Thus, we explored the isolation and bioactivity of a chemical compound, Precocene I, isolated from the perennial grass, Desmosstachya bipinnata (L.) Stapf. Fractions produced from chloroform extractions showed suppressive activity on larvae of Spodoptera litura (Lepidoptera: Noctuidae), the Oriental armyworm. Column chromatography analyses identified Precocene I confirmed using FTIR, HPLC and NMR techniques. The bioactivity of the plant-extracted Dp-Precocene I was compared to a commercially produced Precocene I standard. The percentage of mortality observed in insects fed on plant tissue treated with 60 ppm Db-Precocene I was 97, 87 and 81, respectively, for the second, third and fourth instar larvae. The LC50 value of third instars was 23.2 ppm. The percentages of survival, pupation, fecundity and egg hatch were altered at sub-lethal concentrations of Db-Precocene I (2, 4, 6 and 8 ppm, sprays on castor leaves). The observed effects were negatively correlated with concentration, with a decrease in effects as concentrations increased. Distinct changes in feeding activity and damage to gut tissues were observed upon histological examination of S. litura larvae after the ingestion of Db-Precocene I treatments. Comparative analyses of mortality on a non-target organism, the earthworm, Eisenia fetida, at equal concentrations of Precocene I and two chemical pesticides (cypermethrin and monocrotophos) produced mortality only with the chemical pesticide treatments. These results of Db-Precocene I as a highly active bioactive compound support further research to develop production from the grass D. bipinnata as an affordable resource for Precocene-I-based insecticides.

Sign in / Sign up

Export Citation Format

Share Document