Susceptibility of Euseius concordis (Mesostigmata: Phytoseiidae) to pesticides used in citrus production systems

Abstract

Euseius concordis (Chant) is an important predatory mite found in citrus orchards. The toxicity of 19 pesticides used in citrus orchards on biological and population parameters of this mite was assessed. Our results indicated that formetanate hydrochloride, dimethoate and phosmet were highly harmful (100% mortality) to E. concordis. Carbosulfan, diflubenzuron, fenpropathrin, gamma-cyhalothrin, imidacloprid, lambda-cyhalothrin, lambda-cyhalothrin + thiamethoxam, mineral and vegetable oils, spinosad and thiamethoxam reduced the female's survival and/or fecundity, and were moderately harmful to E. concordis. Besides the acute toxicity, carbosulfan and formetanate hydrochloride were highly persistent [>30 days after spraying (DAS)]; dimethoate was moderately persistent (16-30 DAS); spinosad, gamma-cyhalothrin, lambda-cyhalothrin and lambda-cyhalothrin + thiamethoxam were slightly persistent (5-15 DAS); and the other pesticides were considered to be short-lived (<5 DAS). All compounds except lambda-cyhalothrin and thiamethoxam increased the pre-oviposition period in the female offspring. Carbosulfan, deltamethrin, diflubenzuron, etofenprox, fenpropathrin, gamma-cyhalothrin, mineral and vegetable oils, pyriproxyfen and tebufenozide reduced offspring fecundity, whereas thiamethoxam increased the fecundity. Mineral and vegetable oils reduced female longevity of the predator mite. Regarding population effects, imidacloprid, lambda-cyhalothrin, lambda-cyhalothrin + thiamethoxam and thiamethoxam led to an increase in net reproductive rate (R ), intrinsic rate of increase (r), and finite rate of increase (λ) of E. concordis. Diflubenzuron, etofenprox, and mineral and vegetable oils reduced R , r and λ. All pesticides except beta-cypermethrin, fenpropathrin and imidacloprid reduced the mean generation time (T) of the predator. Therefore, semi-field and field studies are needed to assess the compatibility of these compounds with E. concordis before adoption in IPM programs.

Compatibility of synthetic and biological pesticides with a biocontrol agent Phytoseiulus longipes (Acari: Phytoseiidae)

“…Even 31 days after spraying, these pesticides continue to exert a highly harmful residual activity on P. longipes adults. Previous studies consistently reported similar harmful effects and persistence of pyrethroids and organophosphates on various natural enemies, including phytoseiid species (Abou-Awad and El-Banhawy 1985; Villanueva and Walgenbach 2005;Broufas 2008;Bostanian et al 2010;Hamby et al 2013;Beers and Schmidt 2014;Franco et al 2017;Schmidt-Jeffris et al 2021). These results suggest that organophosphates and pyrethroids are not compatible with P. longipes.…”

“…Interestingly, we also observed that pesticides highly harmful to P. longipes through topical exposure in laboratory conditions are not necessarily persistent under screen-house conditions. These findings highlight the importance of assessing non-target effects on each predator life stage and exposure route Table 5 (continued) (Duso et al 2008;Biondi et al 2013;Put et al 2016;Fernández et al 2017;Franco et al 2017;Bergeron and Schmidt-Jeffris 2020;Döker and Kazak 2020).…”

“…Certain pesticides, initially considered incompatible with biological control through topical exposure, may actually be compatible when it comes to residual exposure (Fernández et al 2017). However, the length of time necessary for an applied pesticide to become innocuous can vary significantly, depending on the predator species and pesticide group (Wanumen et al 2016;Franco et al 2017). For instance, previous studies have shown that residues propargite became harmless to N. californicus 16-30 days post-spraying, suggesting moderate persistence (Uddin et al 2015).…”

“…Conversely, residues of abamectin turned innocuous to Amblyseius swirskii Athias-Henriot, N. californicus and P. persimilis 5-15 days after spraying, suggesting their slight persistence (Van de Veire et al 2002;Sáenz-de-Cabezón Irigaray et al 2007;Ruiz and de Moraes 2008;Nadimi et al 2011;Uddin et al 2015;Fernández et al 2017). On the other hand, Franco et al (2017) and observed harmful effects of imidacloprid on Euseius concordis (Cant) and Iphiseiodes zuluagai Denmark & Muma lasted only three days in citrus, whereas Wanumen et al (2016) reported 34 days of harmful effects on Macrolophus basicornis (Stal) (Heteroptera: Miridae). In line with these findings, our study revealed that the residues of abamectin and oxymatrine remained harmful to P. longipes for 5-15 days post-spraying (IOBC class B, slight persistence), while that of propargite and imidacloprid turned non-toxic to P. longipes 16-30 days after application (IOBC class C, moderate persistence).…”

Fate of Pyriproxyfen in Soils and Plants

“…It allows us to fight pests on a large number of agricultural plants depending on the regulation of the country in which it is used. These plants include apple, almond, apricot, banana, bean, cabbage, carrot, citrus, cotton, cucumber, grape-wine, mango, melon, olive, papaya, pear, pepper, soybean, strawberry, tomato, watermelon, and zucchini [12][13][14][15][16][17][18]. The study of the behavior of pyriproxyfen for a given crop in the growing conditions of a specific area is compulsory to estimate whether the established pre-harvest time ensures that the residue levels are below the maximum residue level (MRL) that is the highest concentration of pesticide that is legally tolerated in or on food when it is applied under good agricultural practices.…”