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Field-collected nymphs and adults of Bagrada hilaris (Burmeister) (Hemiptera: Penatatomidae) from three locations were evaluated for susceptibility to insecticides representing 10 classes of insecticide chemistry. Although relative susceptibilities differed between leaf-spray and leaf-dip Petri dish bioassays, consistently low LC50 values were determined for chlorpyrifos, bifenthrin, and lambda-cyhalothrin. Fenpropathrin and methomyl had intermediate values. Susceptibility to dinotefuran varied depending on the bioassay, possibly owing to leaf substrates used in the two bioassays. In soil systemic bioassays, the LC50 value of dinotefuran was significantly greater than that of two other neonicotinoids, imidacloprid and thiamethoxam, and the anthranilic diamide, cyantraniliprole. Mortality and feeding damage of B. hilaris and plant growth on insecticide-treated plants in greenhouse trials were consistent with the laboratory bioassays; the best results were seen with bifenthrin, methomyl, and chlorpyrifos. Mortality to the neonicotinoids was not evident; however, feeding damage and plant growth responses on dinotefuran-treated plants damage were similar to the noninfested control. This highlights the apparent antifeedant properties of dinotefuran that may have prevented adults from injuring broccoli plants after exposure to foliar spray residues. Data presented serve as baseline susceptibilities that can be used to monitor for resistance development in field populations of B. hilaris., (© The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Background: Development of pyriproxyfen and neonicotinoid resistance in the B-biotype whitefly and recent introduction of the Q biotype have the potential to threaten current whitefly management programs in Arizona. The possibility of integrating the novel anthranilic diamides chlorantraniliprole and cyantraniliprole into the current program to tackle these threats largely depends on whether these compounds have cross-resistance with pyriproxyfen and neonicotinoids in whiteflies. To address this question, the authors bioassayed a susceptible B-biotype strain, a pyriproxyfen-resistant B-biotype strain, four multiply resistant Q-biotype strains and 16 B-biotype field populations from Arizona with a systemic uptake bioassay developed in the present study., Results: The magnitude of variations in LC(50) and LC(99) among the B-biotype populations or the Q-biotype strains was less than fivefold and tenfold, respectively, for both chlorantraniliprole and cyantraniliprole. The Q-biotype strains were relatively more tolerant than the B-biotype populations. No correlations were observed between the LC(50) (or LC(99)) values of the two diamides against the B- and Q-biotype populations tested and their survival rates at a discriminating dose of pyriproxyfen or imidacloprid., Conclusion: These results indicate the absence of cross-resistance between the two anthranilic diamides and the currently used neonicotinoids and pyriproxyfen. Future variation in susceptibility of field populations to chlorantraniliprole and cyantraniliprole could be documented according to the baseline susceptibility range of the populations tested in this study., (Copyright © 2011 Society of Chemical Industry.)

In the 'Integrated Control Concept', Stern et al. emphasized that, although insecticides are necessary for agricultural production, they should only be used as a last resort and as a complement to biological control. They argued that selective insecticide use should only be attempted after it has been determined that insect control with naturally occurring biotic agents is not capable of preventing economic damage. However, they concluded their seminal paper by emphasizing that integrated control will not work where natural enemies are inadequate or where economic thresholds are too low to rely on biological control. Thus, it is no surprise that insect control in high-value, fresh-market lettuce crops grown in the desert southwest have relied almost exclusively on insecticides to control a complex of mobile, polyphagous pests. Because lettuce and leafy greens are short-season annual crops with little or no tolerance for insect damage or contamination, biological control is generally considered unacceptable. High expectations from consumers for aesthetically appealing produce free of pesticide residues further forces vegetable growers to use chemical control tactics that are not only effective but safe. Consequently, scientists have been developing integrated pest management (IPM) programs for lettuce that are aimed at reducing the economic, occupational and dietary risks associated with chemical controls of the past. Most of these programs have drawn upon the integrated control concept and promote the importance of understanding the agroecosystem, and the need to sample for pest status and use action thresholds for cost-effective insect control. More recently, pest management programs have implemented newly developed, reduced-risk chemistries that are selectively efficacious against key pests. This paper discusses the influence that the integrated control concept, relative to zero-tolerance market standards and other constraints, has had on the adoption of pest management in desert lettuce crops., ((c) 2009 Society of Chemical Industry.)

Various insecticide use strategies including rotations, sequential use, and mixtures were evaluated experimentally on Bemisia tabaci (Gennadius) in California and Arizona (U.S.A.) cotton fields. Toxicological responses of adult B. tabaci were measured along with preimaginal densities and cotton yields from plots subjected to different insecticide regimens. Weekly monitoring for susceptibility changes over ten consecutive weeks in four different trials failed to detect significant differences between sequential use and rotation regimens, nor in comparison to the control plots. There were, however, significant differences among study-site locations and between study years as well as significant within-season time effects. Relative infestations in insecticide-treated plots expressed as a percentage of preimaginal densities in control plots indicated that better control was obtained by all insecticide treatments in conjunction with higher susceptibility levels observed in the second year. Lower preimaginal densities of B. tabaci were measured in the rotation treatment in comparison to sequential treatments of endosulfan, chlorpyrifos, or amitraz, but all were less effective than sequential treatments of bifenthrin or the mixture of bifenthrin + endosulfan. Cotton lint yields were inversely related to B. tabaci densities, with highest yields in the bifenthrin and mixture plots and lowest yields in the control plots. Suppression of B. tabaci infestations in insecticide-treated plots relative to untreated control plots also improved under conditions of lower B. tabaci pressure. The increases in cotton yield and susceptibility to insecticides seen in the current study support the trend observed in the southwestern USA of improved management of B. tabaci despite continuing intensive use of insecticides.