Abstract Background: Chile is the second largest avocado producer in the world. However, there have been few studies on interactions between native bees and avocado pollination in a Chilean environment. The flowering period of avocado is very sensitive to temperature fluctuations and so environmental conditions, particularly cool temperatures, can have a strong influence on its floral behaviour. Thus, we aimed to determine whether temperature also influences bee visitation rates to avocado flowers or if this was due to the number of available flowers. Moreover, we proposed to verify the attractiveness of avocado flowers to native bees and compare flower handling time and type of floral resource collected between managed and native bees. Methods: An avocado orchard of “Hass” cultivar located in the Mediterranean region of Chile was studied during the flowering season of 2016. The frequency of exotic and native bee species in flowers, floral phenology, and environmental temperature were analysed, and the foraging behaviours of exotic and native bee species in avocado flowers compared. Results: Five Chilean native and two exotic species were recorded visiting avocado flowers at the studied orchard. The bees generally sought nectar rather than pollen. The European honeybee ( Apis mellifera ) was the most frequent flower visitor, followed by the native species Colletes cyanescens and Cadeguala occidentalis . There was a strong positive correlation between temperature and number of visits, but no significant correlation between number of open flowers and number of visits. Conclusions: Native Chilean bees visited avocado flowers and some of them were frequent floral visitors. They generally sought for nectar rather than pollen and were as fast as honeybees handling avocado flowers. The environmental temperature plays a key role in the frequency of bees in avocado flowers. The warmer weather is related to the higher number of bees visits to avocado flowers.

ABSTRACT Mesochorus species are hyperparasitoids capable of nullifying biological control agents. This study is the first to map and predict the distribution of this genus in Brazil. Species distribution modeling was used to estimate the potential distribution of Mesochorus. We obtained 72 occurrence records of 49 Mesochorus species, being 30 endemics. According to our prediction model, this genus can be distributed in all Brazilian biomes, with higher suitability of occurrence in the Atlantic Forest and lower in the Caatinga and Pampa.

RESUMEN Las especies de Mesochorus son hiperparasitoides capaces de anular los agentes de control biológico. Este estudio es el primero en mapear y predecir la distribución de este género en Brasil. Se utilizó un modelo de distribución de especies para estimar la distribución potencial de Mesochorus. Obtuvimos 72 registros de ocurrencia de 49 especies de Mesochorus, siendo 30 endémicas. De acuerdo con nuestro modelo de predicción, este género se puede distribuir en todos los biomas brasileños, con una mayor idoneidad de ocurrencia en el Bosque Atlántico y menor en la Caatinga y Pampa.

ABSTRACT Orchidaceae is a diverse group with conservation issues all over the World. Due to its endangered situation, knowledge about its reproductive biology is needed to plan conservation strategies. We conducted a study during October 2016 and October 2017 in Maule region, Chile, and discovered the following unreported interactions: Colletes seminitidus Spinola and Astylus trifasciatus Guér. transferring pollen from Bipinnula fimbriata; Centris nigerrima (Spinola) transferring pollen from Chloraea bletioides; Cadeguala occidentalis (Haliday) flower-visiting Chloraea gavilu; Centris cineraria Smith and Megachile saulcyi Guérin-Méneville transferring pollen from Gavilea venosa.

RESUMEN Orchidaceae es un grupo diverso, amenazado en todo el mundo. Debido a su situación de peligro, el conocimiento sobre su biología reproductiva es necesario para planificar estrategias de conservación. Hemos realizado un estudio durante octubre de 2016 y octubre de 2017 en la Región del Maule, descubriendo las siguientes interacciones no reportadas: Colletes seminitidus Spinola y Astylus trifasciatus Guér. visitando Bipinnula fimbriata; Centris nigerrima (Spinola) visitando Chloraea bletioides; Cadeguala occidentalis (Haliday) visitando Chloraea gavilu; Centris cineraria Smith y Megachile saulcyi Guérin-Méneville sacando polen de Gavilea venosa.

RESUMO O tomate é amplamente cultivado em todo o mundo e requer polinização por abelhas nativas ou manejadas para realizar o pleno potencial de produção dos frutos. Para investigar a riqueza e abundância de espécies de abelhas nativas em plantações de tomate do Centro-Oeste do Brasil, dois métodos de amostragem (armadilhas pan-trap e amostragem ativa) foram utilizados em nove propriedades de junho a setembro de 2011. Um total de 465 indivíduos de 44 espécies foi coletado. A composição das espécies de abelhas amostradas diferiu dependendo do método utilizado. Vinte e duas espécies foram capturadas exclusivamente em armadilhas, 13 outras por meio de amostragem ativa e nove por ambos os métodos. A maioria das espécies de abelhas capturadas neste estudo pode ser considerada polinizadores eficazes do tomate, porque elas podem executar a polinização por vibração. Vibrando seus músculos torácicos, essas abelhas podem liberar o pólen das anteras para seus próprios corpos e para os estigmas da mesma flor, uma vez que eles estão dentro do cone de anteras da variedade do tomate estudado. Ambos os métodos amostraram espécies exclusivas de abelhas vibradoras. No entanto, as armadilhas capturaram abelhas vibradoras e não vibradoras indiscriminadamente e o método ativo amostrou principalmente a abelha vibradora. As coletas utilizando armadilhas e amostragens ativas foram complementares. O uso de apenas um método de amostragem não fornece um entendimento completo da riqueza de espécies de polinizadores de tomate no campo.

ABSTRACT The tomato is widely cultivated throughout the world and requires pollination by wild or managed bees to realize its full-potential fruit production. Two different sampling methods (pan trapping and active sampling) were employed in nine different properties from June to September of 2011 to investigate the richness and abundance of native bee species present in tomato crops of Center-West Brazil. A total of 465 individuals of 44 species were collected, with the composition of sampled bee species differing between the methods used. Twenty-two species were exclusively captured in pan traps, 13 others through active sampling and nine by both methods. Most of the sampled bee species can be considered effective pollinators of the tomato because they can perform buzz-pollination. By vibration, these bees can liberate pollen from anthers into the air or onto their own bodies and the stigmas of the same flower because the stigmas of the studied tomato variety are within the anther cone. Both methods exclusively sampled some species of buzz-pollinating bees, however, pan-trapping captured buzzing and non-buzzing visitors indiscriminately while active sampling captured more buzzing bees. Pan-trapping and active sampling appear to complement each other, and so the use of only one or the other would not provide a full understanding of the species richness of tomato pollinators in the field.

Cabralea canjerana subsp. canjerana is a common species in the Atlantic Forest, occurring in several areas of this biome. Yet, little is known about its reproductive strategies. This study aims to understand the reproductive biology of this subspecies, including floral biology, sexual system, and pollination biology. Male and female plants have morphologically similar flowers, but male plants have larger inflorescences with more flowers than female plants. Female flowers remain open and receptive for two days, whereas male flowers last only one day; thus, compensating for the imbalance of the number of flowers per plant between the two sexes. Morphologically similar male and female flowers, as observed in C. canjerana subsp. canjerana, are rare among dioecious species. The high frequency of moths visiting the flowers, the timing of flower opening (anthesis) and nectar production suggests that moths are the pollinators of this subspecies. In contrast to the floral dimorphism found in C. canjerana subsp. polytricha, variations in floral morphology are unrelated to the plant sex in subsp. canjerana. This and other results found in this study suggest that those two subspecies of C. canjerana might be different species.

Cabralea canjerana subsp. canjerana es una especie común en la Mata Atlántica del sudeste de Brasil; sin embargo, poco se sabe acerca de sus estrategias reproductivas. Este estudio tiene como objetivo entender la biología reproductiva de esta subespecie, incluyendo su biología floral, sistema sexual y la biología de la polinización. Las plantas masculinas y femeninas tienen flores morfológicamente similares, pero las plantas masculinas tienen inflorescencias más grandes con más flores que las femeninas. Además, las flores femeninas permanecen abiertas y receptivas por dos días, mientras que las flores masculinas duran sólo un día, compensando así el desequilibrio de la cantidad de flores por planta entre los dos sexos. Flores masculinas y femeninas semejantes, como se observan en C. canjerana subsp. canjerana, son poco comunes entre las especies dioicas. La alta frecuencia de las polillas que visitan las flores, el periodo de apertura de la flor y de la producción de néctar sugieren que las polillas son polinizadores de esta subespecie. Contrastando con el dimorfismo floral encontrado en C. canjerana subsp. polytricha, las variaciones en la morfología floral no están relacionadas con el sexo de la planta en la subsp. canjerana. Este y otros resultados encontrados en este estudio sugieren que estas dos subspecies de C. canjerana podrían ser especies distintas.