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Éditorial: Osmia, une revue d'hyménoptérologie Editorial: Osmia, Journal of Hymenopterology

Editorial letter: a revival for Osmia, the journal of apidologists.

Osmia (Pyrosmia) nana Morawitz 1874 est signalée pour la première fois en France métropolitaine. Osmia (Pyrosmia) nana Morawitz 1874 is recorded for the first time in Metropolitan France.

The limited pollination efficiency of honeybees (Apidae; Apis) for certain crop plants and, more recently, their global decline fostered commercial development of further bee species to complement crop pollination in agricultural systems. In particular, a number of mason bees (Megachilidae; Osmia) are among the most widely used alternative pollinators, and their utilisation has been fine-tuned specifically for pollination in fruit tree orchards. A successful management system should not only aim at optimising pollination efficiency but also consider the relevant biological and ecological requirements to achieve sustainable and healthy bee populations. Here, we review the factors influencing the rate of population increase during the implementation of Osmia bees as orchard pollinators. These factors include nesting material, release methods, and control of antagonists as well as methods optimising management of developmental stages to synchronize bee activity with orchard bloom and to minimize developmental mortality. ISSN:0044-8435 ISSN:1297-9678

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ABSTRACT Pollinating insects provide a vital ecosystem service to crops and wild plants. Exposure to low doses of neonicotinoid insecticides has sub-lethal effects on social pollinators such as bumblebees and honeybees, disturbing their navigation and interfering with their development. Solitary Hymenoptera are also very important ecosystem service providers, but the sub-lethal effects of neonicotinoids have not yet been studied well in those animals. We analyzed the ability of walking Osmia to remember a feeding place in a small environment and found that Osmia remembers the feeding place well after 4 days of training. Uptake of field-realistic amounts of the neonicotinoid clothianidin (0.76 ng per bee) altered the animals9 sensory responses to the visual environment and interfered with the retrieval of navigational memory. We conclude that the neonicotinoid clothianidin compromises visual guidance and the use of navigational memory in the solitary bee Osmia cornuta .

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. Seed- set 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

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First description of the male Osmia (Helicosmia) nasoproducta Ferton, collected in Portugal (Algarve) during spring 2014 at Zavial (37,0461°N - 8,8801°W). Première description du mâle d’Osmia (Helicosmia) nasoproducta Ferton, collecté au Portugal (Algarve) au printemps 2014 à Zavial (37,0461°N - 8,8801°O).

International audience; Microsatellite loci were isolated from the solitary Red Mason bee (Osmia rufa) by an enrichment protocol for partial genomic libraries. Six polymorphic microsatellite loci were used for a first population structure survey including 9 continental European and one island population. Observed levels of genetic variability and heterozygosity proved to be moderate. There was no significant differentiation among continental O. rufa populations. Only the island population from Cyprus was clearly separated. A correlation between geographical and genetic distance indicates gene flow among continental bees. The relatively high homogeneity in O. rufa is probably caused by low effective population size rather than an imprint of past population events. All microsatellites amplified in three further Osmia species.

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International audience; An efficient antioxidant system is of particular importance for insects whose high metabolic rates promote increased formation of reactive oxygen species (ROS). The amount of ROS can be additionally increased by environmental factors. This study investigates the ability of red mason bees (Osmia bicornis L.) to inactivate free radicals during insect development. Both male and female bees were studied, from the larval to the active imago stage. The activity of four antioxidant enzymes, superoxide dismutase, catalase, peroxidase and glutathione S-transferase, was measured; and glutathione content and total antioxidant status were determined. The highest values of the examined parameters were found in feeding stages-in larvae and in active imagines of both genders. Significant differences between genders were noted mainly in catalase activity, which was lower in overwintering imagines and active females than in males. Most differences were observed between females and males after emergence.

International audience; Proper orientation of cocoons in linearly structured nests can be crucial for the survival of hatching bees. Nevertheless, misoriented cocoons appear in nature in notable proportions. A detailed analysis of sex, space available for cocoon spinning, cocoon size, and nest diameter in the red mason bee (Osmia bicornis) showed that smaller males are more prone to misorientation than larger females. Generally, smaller individuals of both sexes are more often misoriented because smaller larvae disregard the direction of the entrance during cocoon construction. Moreover, cocoons in stems of smaller diameter are less often misoriented than bees in wider nests. Our results suggest that cocoon size and available space are the most important traits affecting cocoon orientation.