Companion and Smart Plants: Scientific Background to Promote Conservation Biological Control.

To attain sustainable agricultural crop protection, tools such as host plant resistance, enhanced ecosystem services (i.e. conserving natural enemies) and the deployment of companion plants should be promoted in pest management programmes. These agro system manipulations could be based on chemical ecology studies considering the interactions with natural enemies and pests, regarding specifically plant defence signalling. Further, new crop protection strategies might rise from widening the knowledge regarding how herbivore-induced plant volatiles can govern a multifaceted defence response including natural enemy recruitment, pest repellence or induced defence in neighbouring plants. It is crucial to use a multitrophic approach to understand better the interactions involving companion plants, herbivores and natural enemies in the field, increasing the knowledge to build more efficient and sustainable pest management strategies. In this review, we explore the perspectives of companion plants and their semiochemicals to promote conservation biological control according to the 'smart plants' concept. Further, we discuss the advantages and disadvantages of using companion plants and explore the application of companion plants in different agroecosystems using several case studies.

A parasitoid's dilemma between food and host resources: the role of volatiles from nectar-providing marigolds and host-infested plants attracting Aphidius platensis.

The use of nectar-producing companion plants in crops is a well-known strategy of conserving natural enemies in biological control. However, the role of floral volatiles in attracting parasitoids and effects on host location via herbivore-induced plant volatiles is poorly known. Here, we examined the role of floral volatiles from marigold (Tagetes erecta), alone or in combination with volatiles from sweet pepper plant (Capsicum annuum), in recruiting Aphidius platensis, an important parasitoid of the green peach aphid Myzus persicae. We also investigated whether marigold floral volatiles are more attractive to the parasitoid than those emitted by sweet pepper plants infested by M. persicae. Olfactometry assays indicated that floral volatiles attracted A. platensis to the marigold plant and are more attractive than sweet pepper plant volatiles. However, volatiles emitted by aphid-infested sweet pepper were as attractive to the parasitoid as those of uninfested or aphid-infested blooming marigold. The composition of volatile blends released by uninfested and aphid-infested plants differed between both blooming marigold and sweet pepper, but the parasitoid did not discriminate aphid-infested from uninfested blooming marigold. Volatile released from blooming marigold and sweet pepper shared several compounds, but that of blooming marigold contained larger amounts of fatty-acid derivatives and a different composition of terpenes. We discuss the potential implications of the aphid parasitoid attraction in a diversified crop management strategy.

Differences in the insect fauna associated to a monocultural pasture and a silvopasture in Southeastern Brazil.

A major challenge for global agriculture is the reduction of the environmental impacts caused by meat and dairy production, and the conversion of monocultural pastures to silvopastoral systems has emerged as an important ally in this process. In order to understand the effects of this conversion we analysed 4 years of sampling of the insect fauna from a conventional monocultural pasture and a silvopastoral system in Minas Gerais, Brazil. We aimed to determine whether the changes caused by the conversion affected the abundance, richness and diversity of the insect orders found in the two systems. Total abundance, richness and diversity did not differ between the two systems, but we detected a significant difference in community composition. Several insect orders showed differences in either abundance, richness or diversity between the two systems, and several families of Hymenoptera, which contains pollinators and natural enemies, showed important increases in the silvopasture. Conversion of monocultural pastures to silvopastures can have important consequences on insect fauna involved in essential ecosystem functions, and the implementation of silvopastures at larger scales has the potential to benefit biodiversity conservation and ecosystem service provision at the landscape scale.

Resistance of bioenergy sorghum to Diatraea saccharalis (Lepidoptera: Crambidae) / Resistência de sorgo bioenergia à diatraea saccharalis (lepidoptera: crambidae)

This study evaluated the effects of the sugarcane borer Diatraea saccharalis (Fabricius, 1794) (Lepidoptera: Crambidae) on cultivars of sweet and biomass sorghum for the selection of resistant cultivars. The present work consisted of two trials, with natural pest infestation. In the first one, 10 sweet sorghum cultivars were analyzed for the following variables: plant height, number of healthy and damaged internodes, gallery position and size, stem infestation level and soluble solids content (°Brix). In the second trial, it was analyzed 16 genotypes of high biomass sorghum, with the same variables above mentioned, in addition to the lignin, cellulose and hemicellulose contents. Among sweet sorghum genotypes evaluated, the genotype CMSXS647 stood out due to the traits: plant height, infestation level, gallery size and soluble solids content. Among the sorghum genotypes evaluated, CMSXS7030, CMSXS7012 and CMSXS7028 presented ideal characteristics for infestation level, plant height and number of lignocellulosic compounds. Such information, in addition to supporting the bioenergy sorghum breeding program, will assist in integrated pest management for sorghum cultivation.

Foram estudados os efeitos causados pela broca-do-colmo Diatraea saccharalis (Fabricius, 1794) (Lepidoptera: Crambidae), em cultivares de sorgo sacarino e biomassa visando seleção de cultivares resistentes à praga. O presente trabalho foi constituído de dois ensaios, com infestação natural da praga. No primeiro, 10 cultivares de sorgo sacarino foram analisadas quanto às seguintes variáveis: altura das plantas, quantidade de internódios sadios e com injúrias, posição e tamanho da galeria, intensidade de infestação de colmos e teor de sólidos solúveis (°Brix). No segundo ensaio, foram analisados 16 genótipos de sorgo biomassa, com as mesmas variáveis supracitadas, além dos teores de lignina, celulose e hemicelulose. Entre os genótipos de sorgo sacarino avaliados, o genótipo CMSXS647 foi o que se destacou em função das características: altura de plantas, intensidade de infestação, tamanho de galerias e teor de sólidos solúveis. Entre os genótipos de sorgo biomassa avaliados: CMSXS7030, CMSXS7012 e CMSXS7028 apresentaram características ideais para intensidade de infestação, altura de plantas e quantidade de compostos lignocelulósico. Tais informações, além de prover o programa de melhoramento de sorgo energia podem ajudar o programa de MIP para a cultura do sorgo, uma vez que o produtor conhece a suscetibilidade dos materiais escolhidos.

Stability lies in flowers: Plant diversification mediating shifts in arthropod food webs.

Arthropod community composition in agricultural landscapes is dependent on habitat characteristics, such as plant composition, landscape homogeneity and the presence of key resources, which are usually absent in monocultures. Manipulating agroecosystems through the insertion of in-field floral resources is a useful technique to reduce the deleterious effects of habitat simplification. Food web analysis can clarify how the community reacts to the presence of floral resources which favour ecosystem services such as biological control of pest species. Here, we reported quantitative and qualitative alterations in arthropod food web complexity due to the presence of floral resources from the Mexican marigold (Tagetes erecta L.) in a field scale lettuce community network. The presence of marigold flowers in the field successfully increased richness, body size, and the numerical and biomass abundance of natural enemies in the lettuce arthropod community, which affected the number of links, vulnerability, generality, omnivory rate and food chain length in the community, which are key factors for the stability of relationships between species. Our results reinforce the notion that diversification through insertion of floral resources may assist in preventing pest outbreaks in agroecosystems. This community approach to arthropod interactions in agricultural landscapes can be used in the future to predict the effect of different management practices in the food web to contribute with a more sustainable management of arthropod pest species.

Espécies de Frankliniella (Thysanoptera, Thripidae): novos registros em mangueira (Mangifera indica) no Brasil / Species of Frankliniella (Thysanoptera, Thripidae): new records on mango orchards (Mangifera indica) in Brazil

O objetivo do trabalho foi conhecer as espécies de tripes (Thysanoptera) que atacam pomares de mangueira no semiárido pernambucano. Foram realizadas coletas no período de um ano, em três plantios comerciais da cv. 'Tommy Atkins'. Avaliações semanais foram realizadas em 75 plantas, nos estádios vegetativo e reprodutivo, perfazendo um total de 10.704 amostras em folhas e 390 em panículas. Os espécimes coletados foram levados ao laboratório da Embrapa Semiárido, Petrolina, PE, para triagem dos adultos em microscópio estereoscópico e, posteriormente, enviados à Universidade Federal de Lavras, MG, para identificação. As espécies Frankliniella gardeniae Moulton e Frankliniella Brevicaulis Hood, pertencentes à família Thripidae, representaram, respectivamente, 77 por cento e 23 por cento do total dos tripes coletados. Este estudo relata a primeira ocorrência dessas duas espécies em associação à cultura da mangueira, no Brasil.

The goal of this study was to survey the thrips (Thysanoptera) fauna that attack mango trees in the "semiárido" of Pernambuco. During one year, three commercial orchards of the 'Tommy Atkins' variety were visited. Weekly evaluations were carried out in 75 plants in the vegetative and reproductive stages, totaling 10.704 leaf samples and 390 panicle samples. The adult specimens were sorted using stereomicroscope at the Embrapa Semiárido lab, Petrolina, PE, and sent to the Lavras Federal University, MG, for identification. The species Frankliniella gardeniae Moulton and Frankliniella Brevicaulis Hood, family Thripidae, represented 77 percent and 23 percent of all collected thrips, respectively. This is the first report of these two species occurring in association with mango trees in Brazil.

Occurrence of Lysiphlebus testaceipes parasitizing Aphis gossypii in watermelon in the State of Rio Grande do Norte, Brazil / Ocorrência de Lysiphlebus testaceipes parasitando Aphis gossypii em melancia, no Estado do Rio Grande do Norte, Brasil

This is the first report of the parasitoid Lysiphlebus testaceipes (Cresson) as a biological control agent of the aphid Aphis gossypii Glover in watermelon crop in Vale do Açu, RN. It was observed that near the harvest, almost all collected aphids were mummified, and after analyzing the emerged parasitoids, the parasitoid L. testaceipes was identified. Therefore, in the future, this species may be included in A. gossypii integrated management programs.

Este é o primeiro relato do parasitoide Lysiphlebus testaceipes (Cresson) como agente de controle biológico do pulgão Aphis gossypii Glover na cultura da melancia, na região do Vale do Açu, Rio Grande do Norte (RN). Observou-se que próximo da colheita quase todos os pulgões coletados encontravam-se mumificados e, na análise dos parasitoides emergidos, constatou-se o parasitismo por L. testaceipes. Essa espécie, portanto, poderá ser incluída em um programa de manejo integrado de A. gossypii futuramente.

Orius insidiosus (Say, 1832) (Heteroptera, Anthocoridae): sensibilidade ao fotoperíodo e diapausa reprodutiva? / Orius insidiosus (Say, 1832) (Heteroptera, Anthocoridae): sensitivity to diapause-inducting photoperiods?

The minute pirate bugs, Orius spp., are known as predators on several pests as thrips, aphids, spider mites and whiteflies. Orius insidiosus is an important thrips predator, commercially used around the world. However, one of the main problems on biological control of thrips in temperate regions is the occurrence of reproductive diapause in Orius species. This characteristic promotes the interruption of biological control strategies when predators are exposed to short photoperiods. This research had as objective to evaluate the influence of different photoperiod conditions on eggs/nymphs and adults of O. insidiosus in laboratory. The trials were carried out through the combination of eggs/nymphs and adults reared under the photoperiods 10L:14D; 11L:13D; 12L:12D and 13L:11D, at 25±2°C and 70±10 percent RH. The predators were maintained during their pre-imaginal development time under one of the photoperiods and, after being emerged as adults transferred to another photoperiod regime. The predator had a tendency to present longer development time under photoperiod 13L:11D. There was no influence of the different photoperiods conditions on the reproduction of O. insidiosus. The females laid eggs normally during all their lifetime. O. insidiosus is not sensitive to photoperiod evaluated and do not enter in reproductive diapause.

Record of two species of Orius Wolff (Hemiptera, Anthocoridae) in Brazil

The genus Orius Wolff, 1811 comprises predatory species, with approximately 70 known species. Informations about the genus in Brazil are scarce. Therefore, the aim of this investigation was to identify Orius species present in four localities in the southeastern Brazil. Samples were taken from several plants, and the material screened in laboratory. The genitalia of both sexes were studied and illustrated. Two species were identified, Orius insidiosus (Say, 1832) and Orius thyestes Herring, 1966. O. insidiosus, the most common species, was collected in all of the localities sampled [Lavras (MG), Holambra, Pindorama and Campinas (SP)]. O. thyestes, registered for the first time in Brazil, occurred only in Lavras (MG) and Pindorama (SP). Some morphologic aspects of these two species are also presented