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The physic nut ( Jatropha curcas ) is a potential plant for biofuel production. However, its productivity is limited by pests such as the broad mite ( Polyphagotarsonemus latus ) and the red spider mite ( Tetranychus bastosi ). Despite the problems resulting from their misuse, chemicals are currently the primary method of controlling these herbivorous mites, but biological control by native organisms represents an alternative approach. The predatory mite Typhlodromus transvaalensis (Acari: Phytoseiidae) was collected from J. curcas plants associated with P. latus and T. bastosi in the state of Tocantins, Brazil. We studied predation rates, biological parameters and reproduction of T. transvaalensis feeding on P. latus and T. bastosi as well as the effects of adding pollen from corn ( Zea mays ), physic nut ( J. curcas ) and castor bean ( Ricinus communis ) to the diet. Adult female T. transvaalensis were more efficient at predating all stages of P. latus than T. bastosi . The T. transvaalensis life cycle was shorter with diets including R. communis pollen, but Z. mays pollen was also suitable for reproduction. The results indicate that T. transvaalensis is a generalist predator with high potential for controlling P. latus in J. curcas plantations and that the presence of R. communis and Z. mays crops boosts its development and reproduction.

Pest control is an important ecosystem service that can be enhanced by increasing plant diversity. One of the simplest forms of plant diversification is making use of the occurring weeds that may benefit natural enemies of crop pests. We investigated the interaction between tomato plants, beggar-ticks (Bidens pilosa, Asteraceae), a common weed in Brazil and elsewhere, and the native ladybird beetle Cycloneda sanguinea, an important predator of aphids. The predators occurred on beggar-ticks in the field, independent of the presence of aphids, confirming that they obtained some benefit other than aphid prey from the plants. Predators were attracted to volatiles of clean, flowering beggar-ticks, and volatiles of flowering tomato plants plus flowering beggar-ticks were more attractive than volatiles of tomato plants alone. In the absence of aphids, C. sanguinea did not oviposit on tomato plants, beggar-ticks, or a combination of the two plants, but adult survival was higher on a combination of both plants than on tomato plants alone. These results show that the management of an abundant plant species in agricultural crops has potential for increasing pest control.

Coffee leaf miner (CLM), Leucoptera coffeella, is a key pest of unshaded coffee in hot, dry neotropical production areas. Control is hampered by CLM mining behavior that reduces biological control and pesticide efficacy. Therefore, finding natural enemies that can efficiently control CLM could improve conservation and augmentative biological control practices, and potentially reduce reliance on increasingly ineffective insecticide applications. The green lacewing Ceraeochrysa cubana is a generalist predator often found in coffee crops in Brazil, but there is little information regarding its potential contribution to CLM control. We investigated whether C. cubana preys on immature stages of CLM and whether predation levels vary according to life stage of C. cubana or CLM. First, second and third instar C. cubana readily consumed CLM eggs, but once inside mines, few CLM larvae were consumed. Second and third instar C. cubana successfully preyed on CLM pupae, but first instars did not. Thus, all three instars of C. cubana were able to prey on at least one immature stage of CLM, with potential to impede mine formation and adult emergence.

Aromatic plants can affect arthropod community composition and reduce herbivore populations by attracting beneficial insects such as generalist predators. To investigate the possible mechanisms underlying the attraction of aromatic plant species to natural enemies in the field, we assessed the attractiveness of Ocimum basilicum L. (basil), Mentha piperita L. (peppermint), Melissa officinalis L. (lemon balm) (Lamiaceae) and Cordia verbenacea DC (black sage) (Boraginaceae) to adults of the green lacewing Ceraeochrysa cubana Hagen (Neuroptera: Chrysopidae), a generalist predator widely distributed across the Americas. Additionally, we tested whether access to leaves and flowers of these plant species would affect larval survival, development or oviposition by C. cubana . The green lacewing was attracted to basil but not to the other aromatic plants. Larvae and adults did not benefit from the presence of any plant leaves, but basil flowers enhanced C. cubana larval and adult survival. Basil can be recommended as a companion crop in conservation biological control programs, not only for its well-known negative effects on pests, but also for its attractiveness to generalist predatory insects such as C. cubana . Besides attracting adults, basil flowers benefit both larvae and adults, which is desirable for conservation biological control.

Habitat management enhances heterogeneity in agroecosystems and also has the potential to increase recruitment of spiders, which can improve the biological control services afforded by these important predators. A paucity of studies has documented the associations of spiders with plant communities or the efficacy of non-crop plants for increasing the density and diversity of spider populations. Here we examined natural associations of spiders with native non-crop plants within Brazilian chili pepper agroecosystems. Following this characterization, a manipulative experiment was undertaken at two locations to identify the effects of non-crop plant strips and borders on spider community structure. The composition of native plants altered the community of spiders. The abundance of these predatory spiders was highest on Asteraceae. Spatial Analyses by Distance Indices (SADIE) determined that there was significant aggregation of spiders in chili pepper fields under these plant management strategies. Although incorporating this habitat management approach reduced the overall cropping area, the corresponding increase in generalist predator abundance could offset costs by improving the natural control of pests. This study revealed associations between native plants and spider communities, and how these help to conserve predator biodiversity. Targeted management of native non-crop plants promote the abundance of natural enemies and enhances biological control in chili pepper agroecosystems.

Intercropping tomato plants with coriander is known to attract natural enemies of aphids, mostly coccinellids, but the cues involved in such attraction are not yet known. We investigated why coriander plants attract Cycloneda sanguinea, a generalist aphid predator. We performed a series of controlled experiments with coriander plants in vegetative and reproductive stages to examine the cues attracting C. sanguinea adults and larvae. In a Y-tube olfactometer, C. sanguinea adults were attracted by coriander volatiles produced during the vegetative plant stage suggesting an innate attraction to coriander. Attraction increased when aphid-infested tomato plants were offered together with coriander plants. Moreover, C. sanguinea females used coriander plants as oviposition sites, regardless of plant stage, which could partially explain the attraction to coriander volatiles during vegetative stage. Larvae hatching on coriander plants without prey were able to find nearby aphid-infested tomato plants within about three days after hatching. Additionally, a diet of coriander flowers increased female survivorship, but oviposition only occurred when females had aphids in their diet. Our results indicate that C. sanguinea adults orient to coriander nearing bloom and then use coriander pollen and/or nectar as a supplementary food before aphids become available. The implications of these findings for conservation biological control are discussed.

The two-spotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae) is one of the most important pests of many crops in temperate and tropical climates. Chemical control is the main method of combating this mite, but it is less preferred due to the development of resistance as well as environmental problems associated with the use of pesticides. Biological control of spider mites has been tried as a logical alternative method for chemical control. Studies have been conducted in different countries to assess the effect and potential of natural enemies for controlling the pest. The predatory mite Phytoseiulus macropilis (Banks) (Acari: Phytoseiidae) was found associated with spider mites in strawberry crops in the state of Minas Gerais, Brazil. Earlier studies suggested that P. macropilis was able to control spider mites, but predation and oviposition rates have not been measured so far. We measured predation and oviposition onstrawberry with spider mites as prey in the laboratory. The predator fed on all prey stages and showed capacity to control local prey populations on leaf disks. The oviposition rate of P. macropilis is similar of the most used predatory mite Phytoseiulus persimilis andthe predation rate is higher than that of the latter. Our results suggest that P. macropilis is a promising candidate to control two-spotted spider mites in the tropics and other areas.

Habitat manipulation has long been used as strategy to enhance beneficial insects in agroecosystems. Non-crop weed strips have the potential of supplying food resources to natural enemies, even when pest densities are low. However, in tropical agroecosystems there is a paucity of information pertaining to the resources provided by non-crop weeds and their interactions with natural enemies. In this study we evaluated (a) whether weeds within chili pepper fields affect the diversity and abundance of aphidophagous species; (b) whether there are direct interactions between weeds and aphidophagous arthropods; and (c) the importance of weed floral resources for survival of a native and exotic coccinellid in chili pepper agroecosystems. In the field, aphidophagous arthropods were dominated by Coccinellidae, Syrphidae, Anthocoridae, Neuroptera and Araneae, and these natural enemies were readily observed preying on aphids, feeding on flowers or extrafloral nectaries, and using plant structures for oviposition and/or protection. Survival of native Cycloneda sanguinea (Coleoptera: Coccinellidae) differed between plant species, with significantly greater survival on Ageratum conyzoides and Bidens pilosa. However, no evidence was gathered to suggest that weed floral resources provided any nutritional benefit to the exotic Harmonia axyridis (Coleoptera: Coccinellidae). This research has provided evidence that naturally growing weeds in chili pepper agroecosystems can affect aphid natural enemy abundance and survival, highlighting the need for further research to fully characterize the structure and function of plant resources in these and other tropical agroecosystems.