Toxicity of bifenazate and its principal active metabolite, diazene, to Tetranychus urticae and Panonychus citri and their relative toxicity to the predaceous mites, Phytoseiulus persimilis and Neoseiulus californicus

Abstract

Bifenazate is a novel carbazate acaricide discovered by Uniroyal Chemical (now Chemtura Corporation) for the control of phytophagous mites infesting agricultural and ornamental crops. Its acaricidal activity and that of its principal active metabolite, diazene, were characterized. Bifenazate and diazene had high toxicity and specificity both orally and topically to all life stages of Tetranychus urticae and Panonychus citri. Acute poisoning was observed with no temperature dependency. No cross-resistance was found to mites resistant to several other classes of acaricides, such as tebufenpyrad, etoxazole, fenbutatin oxide and dicofol. Bifenazate remained effective for a long time with only about a 10% loss of efficacy on T. urticae after 1 month of application in the field. All stages of development of the predatory mites, Phytoseiulus persimilis and Neoseiulus californicus, survived treatment by both bifenazate and diazene. When adult females of the two predatory mite species were treated with either bifenazate or diazene, they showed a normal level of fecundity and predatory activity in the laboratory, effectively suppressing spider mite population growth. Even when the predators were fed spider mite eggs that had been treated previously with bifenazate, they survived. These findings indicate that bifenazate is a very useful acaricide giving high efficacy, long-lasting activity and excellent selectivity for spider mites. It is, therefore, concluded that bifenazate is an ideal compound for controlling these pest mites.

Development of acaricide resistance in Pacific spider mite (Tetranychus pacificus) from California vineyards

“…This suggests that additional factors might have been involved in the reported failure of the first propargite application in 2005 in San Joaquin Co., especially since the second application in the same year but at higher rate (Table 1) gave effective control. The LC 50 for bifenazate obtained in our test for the susceptible T. pacificus population is 30-90 times higher than LC 50 values reported for other susceptible tetranychids such as T. urticae and Panonychus ulmi in residual tests (Pree et al 2005;Van Leeuwen et al 2006;Ochiai et al 2007), suggesting that T. pacificus may be more tolerant. Two recent studies suggested that bifenazate acts as a Qo inhibitor, and cytochrome b, a protein encoded by the mitochondrial genome was proposed as its target-site (Van Leeuwen et al 2006.…”

Indirect Effects of Pesticides on Natural Enemies

“…This indicates that these miticides are in fact compatible with this predatory mite. In another study, [22] found that exposure to bifenazate did not reduce fecundity, longevity, or prey consumption of adult female P. persimilis or N. californicus. Moreover, exposure to bifenazate, etoxazole, acequinocyl, and chlorfenapyr under laboratory conditions did not indirectly affect fecundity or reproduction of N. womersleyi females.…”

“…Any indirect effects, which are sometimes referred to as sub-lethal, latent, or cumulative adverse effects may be associated with interfering with the physiology and behavior of natural enemies by inhibiting longevity, fecundity, reproduction (based on the number of progeny produced or eggs laid by females), development time, mobility, searching (foraging) and feeding behavior, predation and/or parasitism, prey consumption, emergence rates, and/or sex ratio [2, 13,16,[17][18][19][20][21][22].…”

Acaricides - Biological Profiles, Effects and Uses in Modern Crop Protection

“…Bifenazate, a carbazate compound (Fig. 5) is highly effective against immatures and adults of spider mites, with rapid knockdown effect (Ochiai et al, 2007). Although it was first considered to be a neurotoxin, more recent experimental results indicate complex III as target site (van Nieuwenhuyse et al, 2009).…”