Residual Acute Toxicity of Some Modern Insecticides Toward Two Mirid Predators of Tomato Pests

Abstract

The successful integration of chemical and biological control strategies for crop pests depends on a thorough evaluation of the effects of pesticides on the natural enemies of pests. A case-by-case review is difficult to achieve because of the many combinations of pests, natural enemies, and crops that need to be tested. Within this framework, we tested and compared seven insecticides representative of four different modes of action (MoAs) groups on closely related predators (Miridae): flubendiamide, spirotetramat, metaflumizone, and sulfoxaflor onNesidiocoris tenuisReuter and flubendiamide, spiromesifen, indoxacarb, and imidacloprid onMacrolophus basicornis(Stal). We follow the standardized methodology of the International Organization for Biological Control, a sequential testing exposure scheme. The lethal effect of each insecticide was evaluated in adults after three days of contact with treated surfaces in the laboratory, extended laboratory, and semifield tests (inert substrate, tomato leaves, and tomato plant as the treated surface, respectively). Flubendiamide, spiromesifen, and spirotetramat were classified as harmless (class 1), metaflumizone was slightly harmful (class 2) but persistent, indoxacarb was harmless (class 1), and sulfoxaflor and imidacloprid were toxic (class 4) and exhibited a long residual activity. Our results suggest similarities in the acute toxicities of insecticides from the same MoA group on related species of natural enemies.

Compatibility of early natural enemy introductions in commercial pepper and tomato greenhouses with repeated pesticide applications

“…The number of mirids per plant in these plots always surpassed the economic threshold of 4.5, which is reported to result in less than 4% damaged tomatoes (Arnó et al, 2011). One application of flubendiamide was also compatible with N. tenuis, released in plants as soon as residues were dried (Wanumen et al, 2016). Two applications of emamectin benzoate impaired the population growth of the NE (IOBC 2; 9%-25% increase in density).…”

“…Therefore, despite the ability of NE to control several pests with simultaneous outbreaks in the crop, chemical treatments are often sometimes needed to maintain key and secondary pest populations under economic thresholds and the ascertaining of their compatibility is crucial for success. Thus, toxicity and sublethal effects of pesticides on NE of horticultural pests has been extensively studied under laboratory or semifield conditions (Amor et al, 2012;Bengochea et al, 2012;Abraham et al, 2013;Döker et al, 2014;Garzón et al, 2015;Maia et al, 2016;Wanumen et al, 2016;De Bortoli et al, 2017;Fernández et al, 2017, Madbouni et al, 2017. In general, much less information is available on the compatibility of novel pesticides and NE inside commercial greenhouses.…”

Selectivity of novel and traditional insecticides used for management of whiteflies on the parasitoid Encarsia formosa

“…Other studies have focused on insect predators, for instance sulfoxaflor was slightly toxic to adults of Chrysoperla carnea (Stephens) and was highly toxic to the fourth instar larvae of Adalia bipunctata (L.) . Moreover, it was shown to be harmful for O. insidiosus (Say) and Nesidiocoris tenuis Reuter, but slightly harmful to Hippodamia convergens Guérin‐Méneville and harmless to C. rufilabris (Burmeister) …”

“…58 Moreover, it was shown to be harmful for O. insidiosus (Say) and Nesidiocoris tenuis Reuter, but slightly harmful to Hippodamia convergens Guérin-Méneville and harmless to C. rufilabris (Burmeister). 59,60 Cyantraniliprole was shown to be slightly toxic toward adults of E. Formosa and Bracon nigricans Szépligeti, and harmless to Tamarixia triozae (Burks) when exposed to its residues. 33,34 Moreover, it did not influence the reproduction of exposed B. nigricans females.…”

An update of the Worldwide Integrated Assessment (WIA) on systemic insecticides. Part 2: impacts on organisms and ecosystems

“…However, 83% of the emerging adults had a number of malformations (Fogel et al 2016). Residues of imidacloprid and thiamethoxam on filter paper appear to repel the predatory beetles Cycloneda sanguinea and Chauliognathus flavipes as well as the predatory bug Orius insidiosus (Fernandes et al 2016), but tomato leaves and plants treated with foliar sprays of imidacloprid at 100 ppm had residual activity and caused 62% mortality of the mirid bug Macrolophus basicornis a month after treatment (Wanumen et al 2016a). The life span of Coccinella septempunctata adults exposed to sublethal doses of imidacloprid sprayed on leaves (4.8 ppm) was reduced by 24-28%, while their fecundity was reduced by 53-56% and the oviposition period was shortened significantly.…”