A New Tool for Resistance Management: Baseline Toxicity, Ovicidal Activity, and Field Efficacy of the Novel Insecticide Tolfenpyrad on Colorado Potato Beetle, <i>Leptinotarsa decemlineata</i>

Abstract

Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae) is one of the most important insect pests of potato (Solanum tuberosum L.). Because of the high value of potato crops, most growers approach management in a similar manner. Chemical control of arthropod pests in potato is the standard pest management practice, and will likely continue to be in the foreseeable future. This heavy reliance on chemical control has led to high levels of insecticide resistance. Strategies that rotate chemistries are critical in order to maintain insecticide efficacy, highlighting the immediate need to evaluate novel chemistries to continue to manage this pest successfully. Working with different populations of L. decemlineata, field and lab experiments were conducted to evaluate the baseline toxicity, ovicidal activity, and field efficacy of the novel insecticide tolfenpyrad to L. decemlineata. Lab assays revealed that tolfenpyrad was toxic to both larvae and adults, and that L. decemlineata treated egg masses had a 0% hatch rate. Potato field plots treated with tolfenpyrad had significantly fewer larvae, less defoliation, and higher tuber yields. These data will provide accurate field rates for proper labeling, a baseline reference for tracking changes in L. decemlineata susceptibility, as well as provide a novel chemistry to aid in resistance management programs.

Toxicity of a novel dsRNA‐based insecticide to the Colorado potato beetle in laboratory and field trials

“…This differs from insect growth regulators such as novaluron which had direct and indirect ovicidal effects 41 and contact insecticides such as tolfenpyrad that had significant ovicidal effects after submerging Colorado potato beetle egg masses in the insecticide. 42 Other dip bioassays have demonstrated a significant lethal effect in Anastrepha fracterculus when larvae were fully submerged in dsRNA. 43 The contact toxicity of ledprona has not yet been assessed, and no life stage apart from eggs were fully submerged in the dsRNA.…”

Effect of two neem-derived pesticides on Colorado potato beetle (Leptinotarsa decemlineata Say) (Coleoptera: Chrysomelidae) under laboratory conditions

“…On the contrary, weak mortality results were obtained in the case of azadirachtin in the no choice test for both the products in choice test. This might be because of the mixed population of the larvae and there is a possibility that the second and third instar larvae have more evolved gut system to digest neem and excrete out the toxic compounds Wimer et al (2015) and sparing the untreated leaf for the first instar larvae with weaker gut system.…”

“…CPB is a multivoltine insect and uncontrolled populations can destroy the whole yield during the growing season (Alkan et al 2017). CPB feeds mostly on solanaceous crops as they contain high concentrations of toxic glycoalkoloids in their foliage which the beetle detoxifies and excrete them with the diet (Wimer et al 2015). Management of CPB using chemical insecticides is a common control measure that is applied since many decades.…”

“…As a result of regular chemical control, CPB is currently resistant to most classes of synthetic insecticides (Kutas and Nádasy 2005). This ability of detoxifying the active compounds can explain their ability to develop resistance to different insecticides (Wimer et al 2015).…”

Residue, dissipation and dietary intake risk assessment of tolfenpyrad in four leafy green vegetables under greenhouse conditions

“…Tolfenpyrad, whose mechanism of action is inhibiting complex I in the respiratory electron-transfer chain of mitochondria, is a new type of pyrazolamide insecticide. Tolfenpyrad could be effective against pests that are resistant to carbamate and organophosphate insecticides ( Wimer et al, 2015 , Yamaguchi et al, 2012 ). In China, tolfenpyrad is only registered for one leafy green vegetable (BBL) for the control of Plutella xylostella L., which is one of the most dominant pests in leafy green vegetable cultivation.…”