The Study of Isolated Alkane Compounds and Crude Extracts From Sphagneticola trilobata (Asterales: Asteraceae) as a Candidate Botanical Insecticide for Lepidopteran Larvae

Abstract

The antifeedant and contact toxicity of Sphagneticola trilobata L. (Asterales: Asteraceae) extracts and isolated alkane compounds were investigated. Leaves of S. trilobata were sequentially extracted with hexane, dichloromethane, ethyl acetate, and methanol. Each extract and the compounds isolated were evaluated against the third instars of Spodoptera litura (F.) (Lepidoptera: Noctuidae), Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae), and Plutella xylostella L. (Lepidoptera: Yponomeutidae). Ethyl acetate extract and isolated alkanes were feeding deterrents as well as contact toxins against all the three species evaluated (FI50 ~ 0.27-2.34 mg/ml; LD50 ~ 0.88-4.2 µg/larvae for ethyl acetate extract, and FI50 ~ 0.06-4.35 mg/ml; LD50 ~ 0.72-3.54 Ethyl acetate extract for isolated alkane). Impact on detoxifying enzymes was variable. The ethyl acetate crude extract reduced carboxylesterase activity in S. litura and P. xylostella while in S. exigua the enzyme was induced. In contrast, glutathione-S-transferase activity was induced in S. exigua but no significant difference in P. xylostella and S.litura was observed. Our results suggest that the S. trilobata extracts have multiple biological activities that contribute to the toxicity in lepidopterans. Variable enzyme responses to the products evaluated in different lepidopteran species also confirm that some species-specific inductions do occur, suggesting the possibility of resistance development in the future, which cannot be summarily ignored. However, for this detailed biochemical studies are required. Multiple bioefficacies of S. trilobata makes it a potential botanical for further exploitation on larger scale so that field potential can be established in any integrated pest management (IPM) system.

Synthesis of thymyl esters and their insecticidal activity against Spodoptera litura (Lepidoptera: Noctuidae)

“…One of the most substantial issues in agriculture is the maximization of the quality of agricultural products through the minimization of insect damage. Spodoptera litura is known as one of the most severe polyphagous insects in the world . The spread of S. litura has led to the use of synthetic insecticides, such as organophosphates, organochlorines, carbamates and pyrethroids, for the protection of crops from insect damage, as these compounds are convenient, fast acting and easy to handle .…”

“…Spodoptera litura is known as one of the most severe polyphagous insects in the world. 1 The spread of S. litura has led to the use of synthetic insecticides, such as organophosphates, organochlorines, carbamates and pyrethroids, for the protection of crops from insect damage, as these compounds are convenient, fast acting and easy to handle. 2,3 The use of chemical control agents has led to a dramatic improvement in the quality of agricultural products.…”

A plant-based extract mixture for controlling Spodoptera litura (Lepidoptera: Noctuidae)

“…In addition to P. nigrum, P. retrofractum, which is in the same genus, also showed larvicidal activity against mosquito larvae C. quinquefasciatus [20]. Moreover, S. trilobata crude extracts have a larvicidal effect on S. litura, S. exigua, and P. xylostella larvae after topical application [21].…”

Methanolic Extract of Winter Cherry Causes Morpho-Histological and Immunological Ailments in Mulberry Pyralid Glyphodes pyloalis

“…However, our results was interestingly different from other studies in giving negative ECD, ECI, and RGR which is indicative of its extreme anti-feedant activity. The feeding deterrence recorded 48 and 87% for 5 and 15% treatments, respectively, clearly indicated the anti-feedant activity (Qi et al, 2003;Luo et al, 2005;Junhirun et al, 2018). This anti-feedant effect is due to the presence of compounds as withanolides such as withanolide A and withanolide D in this plant therefore the insect is unable to efficiently convert food (Budhiraja et al, 2000).…”