Selectivity of pesticides used in rice crop on Telenomus podisi and Trichogramma pretiosum

Abstract

Telenomus and Trichogramma species stand out as agents for the biological control in rice crops, and the main strategy for preserving them is the use of selective pesticides. This study aimed at evaluating the toxicity of pesticides used in irrigated rice crop on Telenomus podisi Ashmead (Hymenoptera: Platygastridae) and Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae). Adults of these parasitoids were exposed to dry residues of pesticides, in a completely randomized experiment, with 25 treatments (24 pesticides + control) and four replications. The insecticides clorantraniliprole, flubendiamide and diflubenzuron and the biological insecticides based on Beauveria bassiana and Metarhizium anisopliae were harmless to T. podisi and T. pretiosum. The harmless herbicides were: 2.4-D amine, profoxydim, quinclorac, ethoxysulfuron and saflufenacil. The fungicide epoxiconazole + kresoxim-methyl was also harmless to these two biological control agents. Therefore, these pesticides are indicated for the integrated pest management, in flooded rice areas.

Insecticide selectivity to Ooencyrtus submetallicus (Hymenoptera: Encyrtidae) under extended laboratory conditions

“…The safety of the insecticides teflubenzuron, triflumuron, tebufenozide, novaluron and methoxyfenozide was observed by Stecca et al (2018), who demonstrated that the T. podisi parasitism in E. heros eggs was similar to the control, corroborating the results obtained in this study. Insecticides from the benzoylphenylurea chemical group are considered to regulate the insect growth, specifically focused on their target insects (Pazini et al 2016, Pazini et al 2017, what may explain the innocuous action of these insecticides on the parasitoid. These insecticides act on the exoskeleton (Sparks & Nauen 2015), inhibiting the chitin synthesis (Stecca et al 2018), and mainly on immature stages, during the process of insect molting, and, thus, rarely reach adult parasitoids (Bastos et al 2006).…”

In silico Approaches for the Ecdysone Receptor of Hemiptera: The First Step for Rational Pesticide Discovery

“…For example, the spinozines obtained from secondary metabolism of Saccharopolyspora spinose, act as allosteric modulator of nicotinic receptor of the post-synaptic nerve in insects (Salgado and Saar, 2004). Further, diamides, the newest mode of action to be introduced for pest control, act as modulator of ryanodine channels with high selectivity for natural enemies (Ramos et al, 2018;Pazini et al, 2016). (Roditakis et al, 2017;Troczka et al, 2012).…”

Differential impacts of pesticides on Euschistus heros (Hem.: Pentatomidae) and its parasitoid Telenomus podisi (Hym.: Platygastridae)

“…and Trichogramma spp. exposed to toxic residues at the recommended concentrations of acephate, imidacloprid, zeta-cypermethrin, thiamethoxam + lambda-cyhalothrin, and other organophosphorus pesticides, pyrethroids, and neonicotinoids commercially formulated in isolation or mixtures 7,9,11,22,39,41,45–47,54,55 .…”

“…heros is based on broad-spectrum insecticides, including organophosphates, pyrethroids, and neonicotinoids 5 , without considering the economic threshold and/or using pesticides tank mixtures 3 . As a result, intensive spraying of insecticides causes several problems, including increased residues in food products, intoxication of users, occurrence of resistant insect populations, resurgence and imbalance of beneficial insects that serve as natural enemies 6–9 . Therefore, the sustainability of soybean crops depends on the development of less hazardous pest management strategies, including biological control and the use of selective agrochemicals 10,11 .…”