The silverleaf whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), is one of the most important pest insects in tomato crop systems worldwide. It has been previously demonstrated that intercropping tomato [Solanum lycopersicum L. Mill. (Solanaceae)] with coriander [Coriandrum sativum L. (Apiaceae)] reduces the incidence and severity of damage caused by B. tabaci. However, it is not yet known how coriander affects the insect′s behaviour. We evaluated the attractiveness of tomato constitutive volatiles to B. tabaci and what effect coriander constitutive volatiles have on the insect′s behaviour. To this end, we conducted three bioassays in a multiple‐choice four‐arm olfactometer (‘×’ type), measuring B. tabaci behaviour when offered tomato and coriander constitutive volatiles presented alone as well as together. We also evaluated the colonisation and establishment of B. tabaci in experimental plots with only single tomato plants and tomatoes intercropped with coriander in a greenhouse. Bemisia tabaci males and females recognised tomato constitutive volatiles as a positive stimulus (kairomonal effect), indicating that semiochemicals from this plant can play an important role in the insect’s host plant selection. Coriander constitutive volatiles reduced the attractiveness of tomato volatiles but no repellency to these volatiles was observed. Greater numbers of adults and nymphs of B. tabaci per plant were observed in tomato monoculture plots than in tomato intercropped with coriander. We suggest that coriander constitutive volatiles have an odour masking effect on tomato volatiles, thus interfering in the host plant selection of B. tabaci.

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Natural enemy conservation is known to be affected by ecological processes that range from local to landscape scales. At the farm scale, there are cropped and noncropped areas that differ in their management and plant diversity; these differences affect the spatiotemporal dynamics of natural enemies. We investigated how different habitat types can affect the conservation and spatial dynamics of predatory and herbivore insects in organic vegetable crops in Brazil. Insects were simultaneously sampled in two cropped (focal and neighbourhood crops) and two noncropped habitats (fallow and native forests) during five consecutive focal crop cycles. We found a higher species richness of predators and herbivores in noncropped habitats. All of the habitats shared species from both functional groups throughout the year, indicating that species could disperse among habitats. Fallow areas can serve as a source and sink for species migrating to/from cropped habitats where predators and herbivores can numerically increase their populations during the crop cycles. The spatiotemporal dynamics of herbivores and predators depend on the management and maintenance of natural, seminatural and cropped habitats within the farm.

Insectivorous bats provide ecosystem services in agricultural and urban landscapes by consuming arthropods that are considered pests. Bat species inhabiting cities are expected to consume insects associated with urban areas, such as mosquitoes, flying termites, moths, and beetles. We captured insectivorous bats in the Federal District of Brazil and used fecal DNA metabarcoding to investigate the arthropod consumed by five bat species living in colonies in city buildings, and ascertained whether their predation was related to ecosystem services. These insectivorous bat species were found to consume 83 morphospecies of arthropods and among these 41 were identified to species, most of which were agricultural pests. We propose that bats may roost in the city areas and forage in the nearby agricultural fields using their ability to fly over long distances. We also calculated the value of the pest suppression ecosystem service by the bats. By a conservative estimation, bats save US$ 94 per hectare of cornfields, accounting for an annual savings of US$ 390.6 million per harvest in Brazil. Our study confirms that, regardless of their roosting location, bats are essential for providing ecosystem services in the cities, with extensive impacts on crops and elsewhere, in addition to significant savings in the use of pesticides.

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The integration of agroforestry plots with ephemeral crops such as vegetables on the farm scale can probably serve as a refuge and source of beneficial insects. Therefore, agroforestry systems possibly represent an alternative that favors ecosystem services and help growers in the transition process from conventional to agro-ecological agriculture. This study aimed to understand the role of introducing agroforestry systems in structuring insect communities, with consequences for the abundance of herbivore and natural enemies, contributing to farm management and favoring biological control as an ecosystem service. Field surveys showed that agroforestry systems can harbor more species than horticultural crops, independent of the functional group. They also contain a greater diversity of herbivores and an even greater diversity profile of natural enemy communities. Agroforestry systems served as a source of natural enemies that can colonize horticultural crops when herbivores are present. As a consequence, natural enemies can establish a numerical response to herbivore abundance, but their communities are also affected by stochastic factors related to climatic conditions. Thus, agroforestry systems and agroecological practices might favor an agriculture based on the maintenance and conservation of ecosystem services.

Population dynamic of Benisua tabaci B biotype in monoculture tomato crop and consortium with coriander in organic and conventional crop system Due to its high genotypic plasticity, the control of the silverleaf whitefly Bemisia tabaci B biotype (Hemiptera: Aleyrodidae), is difficult. This insect may cause severe damage to the tomato crop as a vector of several viruses. The management of the production system and the consortium with other crops may have a direct effect on this herbivore population, without the need of chemical insecticide spraying. The effect of organic and conventional production systems and the tomato-coriander consortium were evaluated in this study, in field, during May-September 2006. Adults of whitefly and its natural enemies were monitored using yellow adhesive traps installed at the edge and inside the experimental plots, and nymphs were sampled by direct observation on tomato plants. Although adult populations in the neighborhood of the different treatments were equivalent, the abundance of whitefly adults was significantly lower in the plots with the consortium tomato-coriander in both systems, conventional and organic. Significant reduction in the amount of nymphs per plant was only observed in the consortium tomato-coriander when all treatments were compared. There were more natural enemies in organic system and a negative correlation was observed between natural enemies abundance collected in the traps and whitefly nymphs' density. The association tomato-coriander and the organic management of the agroecossystem favored natural biological control of B. tabaci.