Activity of spinosad on stored‐tobacco insects and persistence on cured tobacco strips

Abstract

Every year raw tobacco and manufactured tobacco products are lost to two major storage pests, the cigarette beetle, Lasioderma serricorne (F) and the tobacco moth, Ephestia elutella (Hiibner). Post-harvest management of both insects is achieved through sanitation, insect monitoring and fumigation with phosphine. However, insect resistance to phosphine and control failures have been reported, and fumigants are under constant regulatory pressure. Here we report the evaluation of spinosad, a bioinsecticide derived from the fermentation of the soil micro-organism Saccharopolyspora spinosa Mertz & Yao. Spinosad was first registered in 1997 and is now widely used as a field pest control agent on many crops, including tobacco. The insecticidal activity of the fermentation product (technical spinosad, TS) was measured by diet incorporation assays against L serricorne and E elutella larvae. Mortality levels were determined on newly hatched larvae and over the whole insect life cycle. For both species, no emergence of adult insects was observed in cured tobacco sprayed with 50mg TS kg(-1) and inoculated with eggs or newly hatched larvae. These results indicated that spinosad has potential for the control of both species in stored tobacco, since 100% control of both pests could be achieved at 50 mg TS kg(-1), and with almost full control (90-95%) at 10 mg kg(-1). We also monitored the stability of the product on cured tobacco. The original concentration of the main active component of TS, spinosyn A, did not change significantly over 18 months, indicating no loss of spinosad during a typical leaf storage period of time. Bioassays against larvae confirmed that the bioinsecticidal activity of spinosad was retained.

Topical, residual and ovicidal contact toxicity of three reduced‐risk insecticides against the European corn borer, Ostrinia nubilalis (Lepidoptera: Crambidae), on potato

“…The persistence of spinosad is higher than that of indoxacarb, which is higher than that of novaluron. The rapid decline that we observed in the contact toxicity of spinosad residues as they aged from 0.5 to 24 h was somewhat unexpected considering that the persistence and efficacy of spinosad, by ingestion, on stored products are maintained for months 22, 23. The persistence of spinosad is affected by the substrate and drops by half within 22 days on field treated apple leaves 24.…”

Deciphering the Metabolic Pathway Difference Between Saccharopolyspora pogona and Saccharopolyspora spinosa by Comparative Proteomics and Metabonomics

“…For example, butenyl-spinosyn demonstrates good insecticidal activity against worldwide quarantine pest codling moth and the pest insect Helicoverpa assulta (Lewer et al, 2009;ValcÁrcel et al, 2015). Spinosyn has now been commercialized in products, such as Tracer, Success, SpinTor, Conserve, and Entrust (Blanc et al, 2004;Huang et al, 2009). The low biosynthetic ability of butenyl-spinosyn in wild-type S. pogona limits its commercial application.…”

Postharvest management of insects in horticultural products by conventional and organic means, primarily for quarantine purposes

“…These include aldehydes [64], biofumigants [14,65], ethanol vapour [66], ozone [67], p-cymene [68], essential oils [69] and botanical essential oils [70]. Topical organic pesticides include botanicals [71], limonene [72], linalool [73], pyrethroid [74], and spinosad [75].…”

“…This treatment, in combination with mechanical shaking, was shown to be effective in preventing the accidental entry of this pest into Hawaii. The contact bioinsecticide spinosad, derived from the fermentation of the soil micro-organism Saccharopolyspora spinosa, was shown to be effective at a dose of 50 mg TS/kg to control the cigarette beetle, L. serricorne (F) and the tobacco moth, Ephestia elutella (Hübner) in stored tobacco [75].…”