Toxicity of Machaerium opacum (Fabaceae) Leaf Extracts Against Fall Armyworm (Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae)
Bibliographic record
Abstract
Secondary plant metabolites have been widely studied as pest control agents. In this paper we report secondary compounds present in Machaerium opacum leaves, as well as the toxicity of different fractions of the extract of this plant to fall armyworm (Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae)) under laboratory conditions. Crude extracts were obtained by means of ethanol. Refractionation was carried out with the solvents hexane, dichloromethane, methanol and ethyl acetate. By means of preliminary phytochemical prospection, starting with the ethanolic extract, flavonoid, triterpene, anthraquinone, coumarin, tannin and steroid compounds were identified. In the ethanolic fractions, triterpene compounds were identified in a mixture (α-amyrin and β-amyrin), as well as lupeol and the acyclic diterpene alcohol, phytol. In methanolic fractions, the flavonoid rutin was found. In the dichloromethane fraction, the flavonoid mucronulatol and its isomer, isomucronulatol, were found. Extracts of M. opacum did not present an antifeedant effect on the larvae of S. frugiperda. However, all fractions of the extracts tested promoted significant antibiosis effects (reduced weight in the larvae and pupa, larval and pupal mortality and prolongation of the adult phase) on the test population of S. frugiperda. Therefore, our results showed the insecticidal potential of leaf extracts of M. opacum against S. frugiperda.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".