-We studied the pollinating effectiveness of Osmia cornuta and Apis mellifera on 'Comice' pear. Osmia cornuta visited more flowers per minute (13.8) than A. mellifera (7.1-9.8). Both species visited similar numbers of flowers per tree (6.7-7.9), and switched rows with similar frequency (4.0-7.9%). Rate of stigma contact was 98.7% for O. cornuta, 51.8% for A. mellifera pollen-nectar foragers, and 19.0% for A. mellifera nectar foragers. Fruit-set in flowers visited once was 28.9, 29.3, and 12.9%, respectively. Seedset was similar (7-8 seeds per fruit) in all three types of flowers. Osmia cornuta females provisioned their nests with 94.4% pear pollen. Stepwise multiple regression showed that fruitlet-set across the orchard was mostly related to tree size (trees with fewer flowers set more fruit per flower) (β = -0.64; P < 0.001), whereas seed-set at harvest was best explained by O. cornuta (β = 0.47; P < 0.005) and A. mellifera (β = 0.35; P < 0.05) spatial distribution.Osmia cornuta / Apis mellifera / pollinating effectiveness / pear pollination

1. Blueberry is one of the most relevant buzz-pollinated crops worldwide and Chile is the most important global producer of fresh blueberries during wintertime in the Northern Hemisphere. Thousands of exotic Bombus terrestris are imported from Europe to pollinate blueberries. However, no study has investigated the performance of the native Chilean fauna to pollinate blueberry or other crops. Therefore, we aimed to compare the performance of native Chilean floral visitors with managed visitors to pollinate highbush blueberry.2. Per-visit pollination performance (stigmatic pollen deposition) and floral visitation were measured and the presence of sonication behaviour of flower visitors was evaluated for five cultivars in two blueberry orchards located in southern Chile.3. Floral visitors showed a preference for one or more blueberry cultivars, instead of visiting all cultivars equally. Floral visits with sonication deposited more conspecific pollen on stigmas than visits without sonication. Some native sonicating bees (Cadeguala and Bombus), especially Cadeguala occidentalis, were efficient pollen vectors of blueberry and better pollinators than honeybees (5.8 times more pollen transferred) similar to that of the managed bee B. terrestris. 4.The results indicate that some Chilean native bee species, especially those with sonication behaviour, can provide pollination service to highbush blueberry crops. ResumenAbejas nativas con comportamiento de sonicaci on floral pueden lograr un alto rendimiento de la polinizaci on de arándano alto en Chile

La crisis mundial de polinización no solo es producida por la pérdida de polinizadores, sino también por su homogeneización, ambos procesos causados por el ser humano. En este documento analizamos los impactos ecológicos que justifi can la prohibición de nuevos ingresos del abejorro comercial Bombus terrestris a Chile. Esta especie es altamente invasiva y ha sido prohibida en otros países, pero en Chile se permite su ingreso desde 1997. Miles de colonias y reinas fertilizadas ingresan al país cada año y se expanden por el resto de Sudamérica. En este artículo entregamos once razones para detener los ingresos de B. terrestris a Chile y comenzar a controlarlo. Justifi camos estas razones en base al trabajo realizado tanto en el país como fuera de él. Al mismo tiempo, a través de las conclusiones, mencionamos cuáles deberían ser los pasos a seguir respecto a la prohibición de ingreso de B. terrestris a Chile.

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.

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.