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A B S T R A C TThere is limited understanding about how insect movement patterns are influenced by landscape features, and how landscapes can be managed to suppress pest phytophage populations in crops. Theory suggests that the relative timing of pest and natural enemy arrival in crops may influence pest suppression. However, there is a lack of data to substantiate this claim. We investigate the movement patterns of insects from native vegetation (NV) and discuss the implications of these patterns for pest control services. Using bi-directional interception traps we quantified the number of insects crossing an NV/crop ecotone relative to a control crop/crop interface in two agricultural regions early in the growing season. We used these data to infer patterns of movement and net flux. At the community-level, insect movement patterns were influenced by ecotone in two out of three years by region combinations. At the functional-group level, pests and parasitoids showed similar movement patterns from NV very soon after crop emergence. However, movement across the control interface increased towards the end of the earlyseason sampling period. Predators consistently moved more often from NV into crops than vice versa, even after crop emergence. Not all species showed a significant response to ecotone, however when a response was detected, these species showed similar patterns between the two regions. Our results highlight the importance of NV for the recruitment of natural enemies for early season crop immigration that may be potentially important for pest suppression. However, NV was also associated with crop immigration by some pest species. Hence, NV offers both opportunities and risks for pest management. The development of targeted NV management may reduce the risk of crop immigration by pests, but not of natural enemies.Crown

The whitefly Bemisia tabaci Middle East‐Asia Minor 1 (MEAM1), previously known as B biotype, is a major agricultural pest with a reputation for developing resistance to insecticides. DNA‐based identification revealed that B. tabaci MEAM1 is the dominant species within Australian cotton cropping. Discriminating doses of 10 mg/L for pyriproxyfen and 300 mg/L for both diafenthiuron and bifenthrin were determined from bioassay data collected in 2010–2015. Resistance to these insecticides was tested in whitefly populations collected in 2017 from cotton crops in Queensland and New South Wales. This study reports on the presence of pyriproxyfen resistance in B. tabaci MEAM1 at seven locations in Queensland and New South Wales. One population from Goondiwindi was resistant to bifenthrin, whereas no populations tested had resistance to diafenthiuron. To determine the presence of resistance alleles to organophosphates and pyrethroids, reference populations of susceptible and resistant whiteflies (pyriproxyfen, bifenthrin and neonicotinoid) were tested. The resistance mutation L925I was found in a pyrethroid‐resistant population and in some individuals from the pyriproxyfen‐resistant population. The mutation F331W that confers organophosphate and carbamate resistance was found in all individuals tested including the susceptible reference population, indicative of a widespread distribution in Australian B. tabaci MEAM1. The cotton industry has revised the insecticide resistance management strategy for B. tabaci, to restrict the usage of pyriproxyfen to a single application within a 30‐day window. Our results argue against the use of organophosphate and carbamate insecticides in Australian cotton, because B. tabaci MEAM1 populations show significant resistance levels. Furthermore, both pesticide groups are highly disruptive to a diverse range of natural enemy populations, and as such, widespread use likely contributes to pest outbreaks.

Insecticide resistance in Helicoverpa armigera (Hübner) has led to the reduced efficacy of some older insecticide groups (pyrethroids and carbamates) and serious crop losses. Eight small-plot experiments were conducted to evaluate new insecticides for the management of H. armigera in grain crops. Several products showed efficacy equivalent to or better than the commercial standard, thiodicarb. Indoxacarb and spinosad at rates 50% or less of the registered rates for cotton were consistently superior to other tested products across the range of crops treated and provided residual protection for up to 14 d. The insect growth regulator compound, methoxyfenozide, was slower acting than other products tested, but demonstrated potential for H. armigera management. Pyridalyl performed well and warrants further evaluation in grain crops. We discuss the positioning of new compounds in an Insecticide Resistance Management Strategy (IRMS) in relation to a farming system that incorporates both grain and cotton crops. Use guidelines are recommended for indoxacarb, the first new compound to be registered in selected grain crops and cotton in Australia. These guidelines include restricted-use periods and limits on the number of applications per crop. It is anticipated that additional new compounds will be registered in grain crops, leading to the reduced selection pressure on the limited number of efficacious products. Coordinated insecticide use across farming systems and compatibility with developing integrated pest management programs should be fundamental considerations for the future IRMS.