Development and emergence patterns of the tobacco cutworm Spodoptera litura (Lepidoptera: Noctuidae)

Abstract Background Spodoptera litura (Lepidoptera: Noctuidae), the tobacco cutworm, is an prominent agricultural pest. To reduce the use of chemical pesticides that cause health problems and that leave residue in the environment, some botanical pesticides have been developed. Our research aimed to evaluate the insecticidal efficacy of Acorus calamus L. extract for the control of S. litura under laboratory conditions. Results After 24 h of topical application, the A. calamus methanolic crude extract showed toxicity against secondary instar S. litura larvae (LD50 ~ 7.438 µg/larva). Chrysin (5,7-dihydroxy flavone), one of the isolated phenolic compounds, showed optimal control efficiency (LD50 ~ 2.752 µg/larva) and showed a reduction in carboxylesterase activities, which have detoxification reduction roles in larvae. Conclusion Chrysin in the crude extract of A. calamus may be an active compound to control this pest, and it may be applied as an alternative to minimize the usage of chemical insecticides. Graphical Abstract

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The Control Threshold Density of the Tobacco Cutworm Spodoptera litura (Lepidoptera : Noctuidae) on Eggplants and Sweet Peppers in Vinyl-houses

Applied Entomology and Zoology ◽

10.1303/aez.12.184 ◽

1977 ◽

Vol 12 (2) ◽

pp. 184-189 ◽

Cited By ~ 3

Author(s):

Fusao NAKASUJI ◽

Tadami MATSUZAKI

Keyword(s):

Spodoptera Litura ◽

Threshold Density ◽

Tobacco Cutworm ◽

Control Threshold ◽

Lepidoptera Noctuidae

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Effects of sublethal doses of chlorfluazuron on the biochemical constituents of eggs of Spodoptera litura (Lepidoptera: Noctuidae)

The Canadian Entomologist ◽

10.4039/n10-055 ◽

2011 ◽

Vol 143 (2) ◽

pp. 178-184

Author(s):

F. Perveen

Keyword(s):

Embryonic Development ◽

Spodoptera Litura ◽

Treated Male ◽

Biochemical Constituents ◽

Tobacco Cutworm ◽

Sublethal Doses ◽

Lepidoptera Noctuidae

AbstractThe effects of sublethal doses (LD10: 1.00 ng/larva; LD30: 3.75 ng/larva) of chlorfluazuron on the biochemical constituents of eggs of the tobacco cutworm, Spodoptera litura (F.), are described. Chlorfluazuron was applied topically to fifth-instar larvae and the subsequent adults were allowed to mate according to larval treatment (LD10-treated female × LD10-treated male and LD30-treated female × LD30-treated male). Biochemical constituents of eggs resulting from these pairings were analyzed at various stages of embryonic development. Compared with controls, LD10 or LD30 reduced egg constituents as follows: protein (min.–max.) by 32.8%–34.5% or 62.0%–67.3%, lipid by 33%–34% or 62%–67%, carbohydrates by 30%–39% or 60%–67%, DNA by 33%–40% or 60%–69%, RNA by 31%–34% or 59%–67%, and ecdysteroid by 22%–83% or 28%–92%, respectively. The relative proportions of constituents in control eggs were as follows: protein > lipid > carbohydrate, and RNA > DNA. Three low and three high peaks in ecdysteroid titres were observed. Compared with controls, all peaks were reduced in LD10 or LD30 eggs as follows: low peaks: 1st (at 8 h): 32% or 66%; 2nd (at 16 h): 33% or 67%; 3rd (at 52 h): 35% or 65%; high peaks: 1st (at 32 h): 83% or 92%; 2nd (at 64 h): 65% or 82%; 3rd (at 84 h): 84 h, 36% or 63%, respectively. In addition, the first two high peaks were delayed by 4 h in LD10 eggs and by 8 h in LD30 eggs compared with controls. Sublethal doses of chlorfluazuron reduced the amounts of biochemical constituents of eggs during embryogenesis in S. litura.

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