We tested the bioactivity of aqueous extracts of Ludwigia spp. (Myrtales: Onagraceae) on the biological cycle of Plutella xylostella. We assessed the duration of and viability during the larval, pupal and adult phases, as well as the influence of the extracts on the fecundity and hatching of P. xylostella eggs. Subsequently, we phytochemically screened the extracts. The extracts of L. tomentosa and L. longifolia reduced the pupal weight instead of prolonging the larval stage of P. xylostella. The L. tomentosa effect caused higher larval mortality and reduced the fecundity and hatching of P. xylostella eggs, and L. sericea reduced the egg survival. The phenolic compounds—flavonoids, condensed tannins and alkaloids—were more abundant in L. nervosa, L. tomentosa, L. sericea and L. longifolia. The L. tomentosa, L. longifolia and L. sericea extracts were bioactive, and these species showed the best results regarding their ability to control P. xylostella populations, because these plants produce substances able to inhibit food consumption and interfere with the morphological and physiological transformations of the offspring and the oviposition of adults.

Sustainability in food production is an increasingly discussed issue nowadays; therefore, demands for research that can reduce production costs and ensure the quality and autonomy of production are relevant, with attention to the use of plants due to their importance in biodiversity. Thus, the objective of this research was to evaluate the bioactivity, feeding preference, and oviposition preference of Miconia albicans botanical extracts at concentrations of 1%, 5%, and 10% against Plutella xylostella. We observed reduced larval duration, larval survival, female hatching success, and repellence of oviposition and feeding for all concentrations. For higher concentrations, the extracts showed a larval mortality rate of 58%, a feeding reduction of 82%, and an oviposition reduction of 94%, showing potential for pest control. Phytochemical analyses identified phenolic compounds, flavonoids, and tannins, which are substances with repellent and larvicidal properties. This is the first report on the phytosanitary potential of M. albicans, showing that the plant has both lethal and sublethal effects on P. xylostella.

Alternative methods of insect management are an important field of study for agriculture. The current study aimed to determine the effect of aqueous extracts from Simarouba sp. (AE-S) on the biology of Plutella xylostella and to determine the toxicity of the extract to the nematode Caenorhabditis elegans (an important in vivo alternative assay system for toxicological study). Lyophilized AE-S was chemically investigated by Ultrahigh-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). We evaluated the effect of the botanical extract on the life cycle of P. xylostella, from larval stage to adult stage, at concentrations of 10%, 5%, 1%, 0.1%, 0.05%, and 0.01% and a control. Subsequently, we analyzed the toxicity of the extract in an in vivo model. AE-S showed high amount of phenolic and flavonoid compounds. Six compounds were identified based on UHPLC-MS/MS analysis, including flavanone, kaempferol, 4,5-dimethoxycanthin-6-one, 11-acetylamarolide, ailanthinone, and glaucarubinone. The median lethal time for P. xylostella was estimated to be 96 h in all concentrations of AE-S, and at 120 h, 100% of the individuals were dead. Larvae exposed to AE-S at concentrations of 0.01, 0.05, and 0.1% showed a reduction in leaf area consumption, underdevelopment, and reductions in movement and pupal biomass. The lowest concentrations of AE-S (0.1%, 0.05%, and 0.01%) did not cause mortality in nematodes. Thus, the aqueous extract of Simarouba sp. could be an effective control tool because it mainly acts in the larval stage, the stage at which the insect causes damage to brassicaceae.

Plutella xylostella is the primary lepidopteran pest of Brassica crops due to its resistance to numerous insecticides. Multipesticide resistance in insects of agricultural importance is a global problem, and new methods of effective control that are less harmful to the environment are becoming increasingly necessary. The present study analyzed the effects of the aqueous extract of Simarouba sp. at concentrations of 10, 5, 1 and 0.1% in comparison with distilled water (as a control) on the feeding preference, oviposition, and embryonic development of P. xylostella. The results demonstrated that the aqueous extract of Simarouba sp. decreased oviposition and feeding in P. xylostella. A reduction in larval hatching was also observed, indicating ovicidal properties. In particular, the 1% concentration resulted in a more significant decrease in oviposition and the number of hatched larvae. Furthermore, concentrations of 10% and 5% caused food intake suppression, while concentrations of 1% and 0.1% reduced dietary intake by 97% and 78%, respectively. This study highlights the efficacy of Simarouba sp. aqueous extract in controlling the diamondback moth, as larval feeding and the number of individuals reaching the larval stage were reduced. Thus, the control method used in this laboratory study is expected to be successful if utilized on a large scale.

The growing demand for sustainable phytosanitary products has renewed interest in botanical insecticides as viable pest control tools. Amid rising demand for sustainable crop protection, this study screens Cerrado plants traditionally used in medicine to pinpoint bioactive compounds that could replace synthetic pesticides. These products have complex chemical compositions, with compounds acting synergistically through multiple mechanisms, including oral (ingestion of allelochemicals) and topical (contact of allelochemicals on epidermis) toxicity. This study evaluated the oral and topical toxicity of aqueous leaf extracts from Anemopaegma arvense (AEAa), Coussarea hydrangeifolia (AECh), Tapirira guianensis (AETg), and Duguetia furfuracea (AEDf) on Plutella xylostella. In the oral toxicity test, first-instar larvae were fed treated diets until pupation, with biological parameters monitored until adulthood. The extracts caused an average of 45% larval mortality, reduced pupal duration, and lowered egg production. In the topical toxicity test, only the extract from T. guianensis showed significant effect (p = 0.0171), causing 30% mortality in third-instar larvae. The other extracts showed no significant topical toxicity, and AECh showed no lethal or sublethal effects at all. Phytochemical screening was assessed by quantitative spectrophotometric assays, and semi-quantitative classical colorimetric tests. Major compound classes identified were tannins, flavonoids, triterpenoids, coumarins, and alkaloids. These findings highlight the potential of the evaluated plant extracts for pest control, particularly via ingestion, while also underscoring the need for further studies to better understand their efficacy and mechanisms of action.

Botanical insecticides have re-emerged as promising tools within Integrated Pest Management (IPM) due to their biodegradability, chemical diversity, and potential compatibility with resistance management strategies. Although frequently considered safer alternatives to synthetic pesticides, growing evidence indicates that these compounds may also affect non-target organisms, particularly bees. This review discusses the selectivity of botanical insecticides toward pollinators by integrating historical perspectives, mechanisms of action, ecotoxicological effects, and current limitations in risk assessment approaches. Botanical insecticides may induce both lethal and sublethal effects, including alterations in behavior, locomotion, feeding, development, reproduction, and physiology across different bee groups. We also demonstrate that most available studies remain concentrated on Apis mellifera, adult workers, and acute laboratory assays, while important pollinator groups and chronic exposure scenarios remain poorly explored. Furthermore, current regulatory protocols are still largely based on models developed for synthetic pesticides. Expanding ecotoxicological approaches is therefore essential to improve pollinator safety assessments and support more sustainable pest management strategies.