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-The effects of increasing plant diversity on the population of the coffee leaf-miner Leucoptera coffeella (Guérin-Mèneville) were investigated in two organic coffee production systems. One system consisted of coffee intercropped with banana trees (shaded system) and the other one of coffee intercropped with pigeon pea (unshaded system). The increase in plant diversity on both systems was achieved via introduction of green manures such a perennial pea nut, sunn hemp and Brazilian lucerne. The population of L. coffeella, predation and parasitism of L. coffeella mines were biweekly evaluated during eight months. The increase in plant diversity on both systems did not affect the attack of L. coffeella on coffee leaves and the mine parasitism rate. However, there was a positive and signifi cant relationship between increasing plant diversity and coffee leaf mine predation by wasps on unshaded coffee system and a negative relationship on shaded coffee system.

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Current knowledge on coccinellids is primarily focused on their role as natural enemies of soft-bodied insects. However, there is a great diversity of coccinellid parasitoid species that are less studied. Here, we describe new records of coccinellid parasitoids with emphasis on new host-parasitoid interactions in 11 sample sites in Brazil. We collected 122 coccinellid individuals parasitized by six species of parasitoids in the Cerrado and in the Atlantic Rainforest biomes. New records of coccinellid parasitoids and host associations, expansion of habitat ranges and interactions are discussed focusing on the lack of basic information on these interactions in Brazil.

RESUMO.Recentemente, na região produtora de hortaliças de Viçosa, Estado de Minas Gerais, foram identificadas plantas de tomate da cultivar Santa Clara, Lycopersicum esculentum (Solanaceae), que se mostraram potencialmente úteis em programas de melhoramento que visem aumentar a vida de prateleira de frutos. No entanto, essas plantas promissoras, denominadas de 'mutante firme', apresentam senescência foliar precoce e redução do tamanho médio dos frutos, quando o gene se encontra no estado homozigótico recessivo, sendo visualmente normal quando no estado heterozigótico. Assim o objetivo do presente trabalho foi avaliar os níveis de pigmentos foliares em diferentes posições da planta e em diferentes tempos de cultivo, pelos métodos descritos por Lichtenthaler (1987) e pelo índice SPAD (Soil Plant Analylitical Division Value), para verificar a ocorrência ou não de comportamento diferencial de indivíduos heterozigotos em relação aos progenitores Santa Clara e ao mutante 'firme'. Para isso, foram realizados dois experimentos, empregando-se plantas cultivadas em vasos, submetidas a condições de casa-de-vegetação e arranjadas em delineamento inteiramente casualizado. Os resultados das análises, pelo método de Lichtenthaler (1987) mostraram que a clorofila e os pigmentos carotenóides são degradados mais precocemente no mutante 'firme' em relação à cultivar Santa Clara. Além do que, pelo índice SPAD observou-se que os indivíduos, portando a mutação no estado heterozigótico, e os da cultivar Santa Clara apresentaram taxas similares de degradação de clorofila em relação ao tempo de cultivo. Com isso, pode-se concluir que a mutação no estado heterozigótico, em cruzamento com Santa Clara, tem seus efeitos restaurados para esses caracteres bioquímicos. Palavras-chave:Lycopersicon esculentum, mutante 'firme', degradação de clorofila.ABSTRACT. Chlorophyll level evaluation in tomatoes leaves of Santa Clara cultivar, of 'firme' mutant and hybrid F 1 . Recently, in Viçosa (MG), a region of vegetable crop producing, tomatoes of Santa Clara cultivar, Lycopersicum esculentum (Solanaceae), that showed potential use for breeding programs, aiming to increase the shelf life of the fruit were identified. However, plants from the mutant 'firme' have precocious fealf senescence and reduction of the average fruit size when in homozygous background. The objective of the present study was the evaluation of the pigment levels in the leaves on different development positions and stage, utilizing the method described by Lichtenthaler (1987) and the SPAD (Soil Plant Analytical Division Value) in heterozygous mutant related to the progenitor Santa Clara cultivar and the homozygous mutant 'firme'. Thus, two experiments containing two plants per vase grown in greenhouse and arranged at complete randomized way were set up. The data obtained through the Lichtenthaler (1987) method showed that the chlorophyll and carotenoid pigments were degraded earlier in the homozygous mutant 'firme' in comparison to Santa Clara cultivar. While using the SPAD the hete...

Environmental heterogeneity can have profound effects on agroecosystem function and it is important for improving ecosystem services such as biological control. Promoting system diversity via noncrop plants is one method for increasing habitat heterogeneity within farmscapes. Non-crop plants provide access to refuges and alternative food resources provide multiple benefits to enhance populations of arthropod predators. In this study, we examined the effects of small-scale spatial structure on life-stage specific interactions between the native coccinellid, Hippodamia convergens Gu erin-M eneville, and the exotic Harmonia axyridis (Pallas) (both Coleoptera: Coccinellidae), which overlap in spatial distribution in many crop systems. Squash [Cucurbita pepo L. (Cucurbitaceae)] and non-crop mugwort [Artemisia vulgaris L. (Asteraceae)] plants with and without aphids were used as a model of spatial heterogeneity in micro-and mesocosm experiments. In response to factorial treatment combinations, we evaluated oviposition behavior, egg predation, larval survival, and larval predator-prey and predator-predator interactions. Adult H. convergens displayed higher foraging activity on aphids when exposed to complex habitats containing a non-crop plant. In the presence of the exotic coccinellid, H. convergens preferred to deposit eggs on the non-crop plant. Furthermore, a combination of spatial heterogeneity and prey availability reduced larval intraguild predation and cannibalism, and improved reproductive output of H. convergens by reducing intra-and interspecific egg predation. Our results provide evidence that life-stage-specific intraguild interactions are mediated by access to non-crop plants. Thus, the introduction or maintenance of non-crop plants has the potential to enhance coexistence of multiple natural enemies and improve top-down control of pests.