Foliar persistence and residual activity of methoxyfenozide against beet armyworm (Lepidoptera: Noctuidae)

Abstract

A greenhouse study was conducted to investigate the persistence of methoxyfenozide in pepper (Capsicum annuum L.) foliage. An aqueous suspension of methoxyfenozide was sprayed on pepper plants at concentrations of 72 and 144 mg of active ingredient (a.i.)/L. Foliage was collected at different intervals of time (0, 3, 5, 10, 20, 30, 40, and 50 days) after the treatment, and the methoxyfenozide residue was measured by high-performance liquid chromatography. The foliage was also used in bioassays to determine the residual toxicity on and the consumption rate of the third-instar larvae of the beet armyworm, Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae). The methoxyfenozide concentrations observed after 50 days had decreased to 19 and 69 μg/g per sample, corresponding to a loss of 61% and 28% from the application concentrations of 72 and 144 mg a.i./L, respectively. When fitting a first-order kinetics degradation model, the half-life (DT50 ) of this compound was 76 days. Both application concentrations of methoxyfenozide caused a high mortality rate (≥97%) when the larvae were fed the pepper foliage collected at all of the time intervals. Lastly, at all of the time points, the consumption rate by the larvae was reduced to between 57% and 92% for both concentrations that were bioassayed. Our results indicate that, under the present greenhouse conditions, the degradation of methoxyfenozide was slower than that reported by other authors and that its residues were highly toxic to S. exigua larvae. The implications of these results for the management programs of this pest are discussed.

Residue dissipation and dietary exposure risk assessment of methoxyfenozide in cauliflower and tea via modified QuEChERS using UPLC/MS/MS

“…With its successive application in pest control, methoxyfenozide has further found efficacy against Spodoptera exigua , diamondback moth ( Plutella xylostella L.) and Spodoptera litura , which are among the major pests in cauliflower . As for pests in tea gardens, methoxyfenozide has only been confirmed to be effective against tea leaf roller and tea geometrid ( Ectropis obliqua ) so far.…”

Broflanilide effectively controls Helicoverpa armigera and Spodoptera exigua exhibiting diverse susceptibilities to chlorantraniliprole and emamectin benzoate

“…[7][8][9][10][11][12][13] For example, endosulfan, cypermethrin and fenvalerate significantly reduce larval population of H. armigera in tomato. 12 Additionally, S. exigua larvae are controlled effectively by many broadspectrum insecticides, such as spinosad, 11 tebufenozide, 14 methoxyfenozide, 15 chlorfenapyr 14,16 and indoxacarb. 13,14,17 Zhang et al 13 reported that emamectin benzoate, lambdacyhalothrin and chlorantraniliprole exhibit excellent rapid and long-term control against S. exigua up to 10 days, whereas indoxacarb exhibits a poor fast-action within 3 days but an excellent duration of 7-10 days.…”

“…For example, endosulfan, cypermethrin and fenvalerate significantly reduce larval population of H. armigera in tomato 12 . Additionally, S. exigua larvae are controlled effectively by many broad‐spectrum insecticides, such as spinosad, 11 tebufenozide, 14 methoxyfenozide, 15 chlorfenapyr 14,16 and indoxacarb 13,14,17 . Zhang et al 13 .…”

Design, Synthesis, and Insecticidal Activity of Some Novel Diacylhydrazine and Acylhydrazone Derivatives

“…Diacylhydrazines have been identified as one of the most important types of insect regulators since the discovery of the N - tert -butyl- N , N '-diacylhydrazines in the mid-1980s by Rohm and Haas [ 13 , 14 , 15 ]. Several commercial compounds, such as tebufenozide, methoxyfenozide, chromafenozide, and halofenozide, are all classified as diacylhydrazines, and all of these insecticides affect the ecdysone receptor complex, leading to precocious lethal molting, especially in caterpillars [ 16 , 17 ]. Diacylhydrazines have attracted significant attention because of their high insecticidal selectivity, simple structure, and low toxicity to vertebrates [ 15 ].…”