Secondary Metabolites of Asclepias curassavica (Apocynaceae) and its Effects on Food Preference and Mortality of Spodoptera frugiperda (Lepidoptera: Noctuidae)

Abstract

Asclepias curassavica L. plant is toxic for vertebrates, and little is known about its effects on invertebrates, as well as whether its secondary metabolites have an influence on food preference and survival of insects. Thus, a study was conducted to verify the action of A. curassavica on Spodoptera frugiperda J.E.Smith. The plants were collected, dried and ground to compose a crude ethanolic extract. Food tests were carried out with and without opportunity of choice, using corn leaf discs immersed in the extract at concentrations of 1%, 2% and 4%, for assessment of food consumption (g) and preference index. Later, the extract was topically applied on second- and fifth-instar caterpillars, at concentrations of 1%, 2%, 4% and 6%, in order to observe its effect on survival. In parallel, analysis was conducted to verify the presence and measure the amount of total polyphenols and flavonoids in the extract. There was contact action between the extract and second-instar caterpillars at all concentrations, with treatment 6% causing 100% of mortality 72 hours after application. None of the treatments promoted contact action on fifth-instar caterpillars. In food tests with and without opportunity of choice, all treatments caused reductions in consumption, which classified all as phagodeterrent, with treatment 4% standing out as the least favorite. The presence of total polyphenols and flavonoids was found in the extract, presenting 58.75 ug/mL and 150.1 ug/mL, respectively. The A. curassavica extract proved promising in S. frugiperda control.

Productivity and Phytochemicals of Asclepias curassavica in Response to Compost and Silver Nanoparticles Application: HPLC Analysis and Antibacterial Activity of Extracts

“…The peaks in the 3443 cm −1 and 2924 cm −1 were attributed to the aldehyde-C-H- and O-H-stretching of alcohol compounds [ 54 , 55 ]. The existence of C=O groups (aldehydes and ketones) in the produced AgNPs was confirmed by the peak at 2362 cm −1 [ 40 ]. Furthermore, the peak found at 1633 cm −1 demonstrated the carbonyl group’s (C=O) stretching vibration and the amine group’s N-H bending [ 55 ].…”

“…Cardenolides, which were isolated from A. curassavica, Plants 2023, 12, 2274 3 of 22 and their derivatives covenosigenin, glucopyranoside, and acospectoside play a significant role as termite antifeedants [38,39]. The extract included total polyphenols and flavonoids presenting 58.75 µg/mL and 150.1 µg/mL, respectively, and showed promise in the control of Spodoptera frugiperda J.E.Smith [40].…”

Host Plant Species Influences the Composition of Milkweed and Monarch Microbiomes

“…However, Asclepias spp. also produce an array of additional secondary plant compounds which can also be unique to species ( Agrawal et al, 2009 ; Araya et al, 2012 ; de Leão et al, 2020 ). Therefore the unique defensive profiles of milkweed species could enrich for taxonomically different groups of microbes that are either insensitive to or capable of metabolizing variable amounts and types of phytotoxins, without affecting overall species richness in communities.…”

Toxicity of Bioactive Compounds of Strychnos pseudoquina (Loganiaceae) in Spodoptera frugiperda (Noctuidae)

“…The control of this pest is usually carried out with organosynthetic insecticides that, despite being efficient, can cause damage to the environment and human health when applied in excess or incorrectly [8,9]. The use of genetically modified crops, such as Bttransgenic maize, is another strategy to control this pest, as they contain proteins from the bacterium Bacillus thuringiensis which have insecticidal action [10].…”

“…[11] pointed out that this strategy is more efficient in decreasing damage, even when combined with the application of insecticides, as the selection pressure of continuous planting of Bt maize may have been one of the causes of the evolution of S. frugiperda that resulted in its resistance to these proteins [10]. Bioactive compounds extracted from plants have often been shown to be promising alternatives to synthetic compounds to control insects, as they contain substances that are less harmful to non-target organisms, such as natural enemies, pollinators, and humans [8,12,13]. Therefore, these compounds have been used as models for obtaining synthetic insecticides, as well as extracts from specific plant parts, which have been used as low-cost insecticidal alternatives [14,15].…”