One of the most studied plant species with insecticidal properties is the castor beanRicinus communis. However, its activity against Spodoptera frugiperda is unclear. Therefore, to determinate the insecticidal and insectistatic activities of methanol, hexane and ethyl acetate extracts of the seeds and leaves of R. communis, castor oil and ricinine were tested at different concentrations against S. frugiperda. This study demonstrated for the first time, that the castor oil and ricinine are active ingredients of R. communis that acts against S. frugiperda and that each of the seed extracts exhibited better insecticidal and insectistatic activity than the leaf extracts. The half maximum larvae viability concentration (LVC50) were 0.38 × 103mg ml-1 for the ricinine, 0.75 × 103 mg ml-1 for a methanol extract of seeds, 1.97 × 103 mg ml-1 for an ethyl acetate seed extract, 2.69×103 mg ml-1 for the castor oil, 4.83 × 103 mg ml-1 for a methanol extract of leaves, 5.07 × 103 mg ml-1 for an ethyl acetate extract of leaves, 9.95 × 103 mg ml-1 for a hexane extract of seeds and 10.01 × 103 mg ml-1 for a hexane extract of leaves. Key words: Ricinus communis, Spodoptera frugiperda, insecticidal, insectistatic, castor oil, ricinine.

Essential oils can be used as an alternative to using synthetic insecticides for pest management. Therefore, the insectistatic and insecticidal activities of the essential oil of aerial parts of Salvia ballotiflora (Lamiaceae) were tested against the fall armyworm Spodoptera frugiperda (Lepidoptera: Noctuidae). The results demonstrated insecticidal and insectistatical activities against this insect pest with concentrations at 80 µg·mL⁻¹ resulting in 20% larval viability and 10% pupal viability. The larval viability fifty (LV₅₀) corresponded to a concentration of 128.8 µg·mL⁻¹. This oil also increased the duration of the larval phase by 5.5 days and reduced the pupal weight by 29.2% withrespect to the control. The GC-MS analysis of the essential oil of S. ballotiflora showed its main components to be caryophyllene oxide (15.97%), and β-caryophyllene (12.74%), which showed insecticidal and insectistatical activities against S. frugiperda. The insecticidal activity of β-caryophyllene began at 80 µg·mL⁻¹, giving a larval viability of 25% and viability pupal of 20%. The insectistatic activity also started at 80 µg·mL⁻¹ reducing the pupal weight by 22.1% with respect to control. Caryophyllene oxide showed insecticidal activity at 80 µg·mL⁻¹ giving a larval viability of 35% and viability pupal of 20%.The insectistatic activity started at 400 µg·mL⁻¹ and increased the larval phase by 8.8% days with respect to control. The LV₅₀ values for these compounds were 153.1 and 146.5 µg·mL⁻¹, respectively.

Plant extracts can be used as an alternative to synthetic insecticides for the control of insect pests. Based on this knowledge, juvenomimetic and insecticidal activities of n-hexane extracts of the aerial parts of Senecio salignus DC. (Asteraceae) and Salvia microphylla Kunth (Lamiaceae) collected in Mexico were evaluated against 1st instar larvae of Spodoptera frugiperda Smith & Abbot (Lepidoptera: Noctuidae). Senecio salignus extract showed insecticidal activity at 500 ppm, resulting in larval mortality of 52.5% and pupal mortality of 62.5%. Salvia microphylla extract at the same concentration caused larval mortality of 65.0% and pupal mortality of 82.5%. The LC50 was 440 ppm for S. salignus extract and 456 ppm for S. microphylla extract based on the total larval period. The juvenomimetic activity of S. salignus extract at 500 ppm increased the duration of the larval period to 17.3 d and of the pupal period to 1.4 d. It also reduced pupal weight by 34.7% with respect to the control (241 mg). F... Resumen Los extractos de plantas pueden ser usados como alternativa al empleo de insecticidas químico sintéticos para el control de insectos plaga. Basándose en este conocimiento, se evaluaron las actividades insecticida y juvenomimética del extracto n-hexano de las partes aéreas de Senecio salignus DC. (Asteraceae) y de Salvia microphylla Kunth (Lamiaceae) colectadas en Mexico, contra larvas del primer estadio de Spodoptera frugiperda Smith & Abbot (Lepidoptera: Noctuidae). El extracto de S. salignus mostró actividad insecticida a 500 ppm, ocasionando 52.5% de mortalidad larval y 62.5% de mortalidad pupal. El extracto de S. microphylla causó una mortalidad larval de 65.0% a 500 ppm y una mortalidad pupal de 82.5% con la misma concentración. La concentración letal media (LC50) fue de 440 ppm para el extracto de S. salignus y de 456 ppm para el extracto de S. microphylla para todo el periodo larval. La actividad juvenomimética de S. salignus a 500 ppm resultó en el incremento de la fase larval de 17.3 dias...

The composition of a chloroform seed extract of C. papaya was determined by GC-MS. Nineteen compounds were identified, with oleic (45.97%), palmitic (24.1%) and stearic (8.52%) acids being the main components. The insecticidal and insectistatic activities of the extract and the three main constituents were tested. Larval duration increased by 3.4 d and 2.5 d when the extract was used at 16,000 and 9,600 ppm, respectively, whereas the pupal period increased by 2.2 d and 1.1 d at the same concentrations. Larval viability values were 0%, 29.2%, and 50% when the extract was applied at 24,000, 16,000, and 9,600 ppm, respectively; pupal viability was 42.9% and 66.7% at 16,000 and 9,600 ppm; and pupal weight decreased by 25.4% and 11.5% at 16,000 and 9,600 ppm. The larval viability of the main compounds was 33.3%, 48.5%, and 62.5% when exposed to 1,600 ppm of palmitic acid, oleic acid, or stearic acid, respectively.

Neonicotinoids are a group of insecticides developed in the 1980s, reaching extensive use in agriculture in the 1990s due to their effectiveness against pests in various types of crops. In 2014, their use reached 25% of the global market. In the last decade, studies on their possible effects have been conducted, leading to bans and regulations in several European Union countries. Their persistence in soil and water can result in chronic exposure in aquatic and terrestrial organisms, including pollinator species. The accumulation of these compounds in the environment can disrupt ecosystems and affect the health of humans, plants, and animals. This review presents current knowledge on neonicotinoids, their mechanisms of action, and their transport in ecological spheres. Their presence in water and soil is evidenced, with specific concentrations reported in various regions. Their effects on non-target organisms, including aquatic animals and humans, can be negative, causing direct and indirect neurological and renal problems after exposure. More research is needed on the long-term effects on health and non-target organisms to fully understand the implications of these insecticides.