Pyridalyl, a novel insecticide: Potency and insecticidal selectivity

Abstract

Pyridalyl is an insecticide of a novel chemical class (unclassified insecticides). Toxicity of pyridalyl to two insect pest species, Spodoptera litura and Frankliniella occidentalis, an insect predator, Orius stringicollis, and a pollinator, Bombus terrestris, was evaluated in the laboratory. The insecticidal activity of pyridalyl against S. litura was evaluated using the leaf-dipping method. The potency of pyridalyl was highly effective against all development stages (2nd to 6th instar larvae) of S. litura. This compound was also evaluated against F. occidentalis using the direct spray method. For F. occidentalis, toxicity of pyridalyl was almost similar to that of acrinathrin, but greater than acrinathrin for adults. Then the toxicity of this product to the natural enemies, Orius stringicollis and the pollinating insect Bombus terrestris, was evaluated using the body-dipping method or direct spray method. No acute toxicity of this product was observed on these non-target insects. Moreover, the influence of pyridalyl to the nest of Bombus terrestris was evaluated using the direct spray to the inside of the nest. No apparent influence of this compound was observed by 21 days after treatment. The cytotoxicity of pyridalyl to the Sf9 insect cell line and the CHO-K1 mammalian cell line was evaluated using the trypan-blue exclusion method. High toxicity to the insect cell line, but almost no toxicity to the mammalian cell line, was observed. Thus, pyridalyl exhibited high selectivity in cytotoxicity between the insect and mammalian cell line as well as in insecticidal activity among insect species. We infer pyridalyl may be useful for IPM programs of greenhouse cultivation system.

Different responses of a solitary (Meteorus pulchricornis) and a gregarious (Cotesia kariyai) endoparasitoid to four insecticides in the host Pseudaletia separata

“…28) Lepidopteran larvae are rendered motionless after treatment, which causes muscle relaxation. C. kariyai can emerge from their motionless hosts treated with pyridalyl at 8 and 9 d post-parasitization.…”

Management strategies for western flower thrips in vegetable greenhouses in Iran: a review

“…Pyridalyl was produced from two compounds with known insecticidal activity (3,3-dichloro-2-propenyloxy group, 2-(trifluoromethyl)-4-phenoxyphenyl 3,3-dichloro-2-propenyl) and it belongs to a new class of insecticides (unclassified insecticides) Isayama et al 2005). Pyridalyl was firstly marketed in Japan (Isayama et al 2005).…”

“…Pyridalyl has a high selectivity in cytotoxicity between the insects and mammals . It displays no acute toxicity to non-target insects such as beneficial insects Isayama et al 2005). Therefore, it is an attractive insecticide for rotational use in integrated pest management programs.…”

Management Strategies for Western Flower Thrips and the Role of Insecticides

“…Other newly developed insecticides with novel modes of action continue to be evaluated for their potential role in western flower thrips management. Pyridalyl, which has not been classified as yet for its mode of action, is more toxic to larvae than to adults of the western flower thrips, but it is compatible with biological control agents such the predatory bug Orius strigicollis (Poppius) (Isayama et al, 2005). This feature makes it an attractive insecticide for rotational use in an overall integrated pest management program.…”