Sex allocation in the solitary bee Osmia cornuta: Do females behave in agreement with Fisher's theory?

Bosch J., Vicens N. (2005) Sex allocation in the solitary bee Osmia cornuta: Do females behave in agreement with Fisher's theory?. Behavioral Ecology and Sociobiology. 59: 124-132.
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Doi: 10.1007/s00265-005-0017-8

Resum:

Fisher's theory of sex allocation predicts that, in a panmictic population, parental investment will be equally distributed between male and female progeny. Most studies on parental investment in nesting solitary bees and wasps use offspring or provision weight as estimators of parental investment and do not corroborate Fisher's theory. The measurement of parental investment may be confounded by several factors. First, the use of offspring or provision size does not account for seasonal variation in foraging costs associated with aging of nesting females. Second, provision or offspring size do not reflect parental investment associated with nest construction. In this two-year study we measured parental investment in a solitary bee. We calculated sex allocation using both provision weight and foraging time as parental investment estimators. Investment in pollen-nectar provisions decreased, while investment in mud structures (nest construction) increased, as the nesting period progressed. Overall investment in provisions per nest was ∼25 times higher than investment in mud. Pollen-nectar foraging trips became longer as the season progressed, but mud trip duration did not vary. Due to weather differences between years, more offspring per female were produced in the first year, but progeny sex ratio and mean offspring size of both sexes were similar between years. Mortality did not differ between sexes. As predicted by Fisher's theory, production cost ratios did not differ from 1 in either year, irrespective of the currency used to estimate parental investment (provision weight or foraging time). Our results strongly support Fisher's theory. © Springer-Verlag 2005.

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The relative importance of vertical and horizontal visual cues in nest location by Megachile rotundata (F.) (Hymenoptera: Megachilidae).

Guédot C, Bosch J, Kemp WP (2005) The relative importance of vertical and horizontal visual cues in nest location by Megachile rotundata (F.) (Hymenoptera: Megachilidae). Journal of Apicultural Research 44: 109-115.

Temporal variation in overwintering gene expression and respiration in the solitary bee Megachile rotundata.

Yocum GD, Kemp WP, Bosch J, Knoblett JN (2005) Temporal variation in overwintering gene expression and respiration in the solitary bee Megachile rotundata. Journal of Insect Physiology 51: 621-629.

Alfalfa leafcutting bee population dynamics, flower availability, and pollination rates in two Oregon alfalfa fields.

Bosch J, Kemp WP (2005) Alfalfa leafcutting bee population dynamics, flower availability, and pollination rates in two Oregon alfalfa fields. Journal of Economic Entomology 98: 1077-1086.

Resumen de la II reunión del grupo de trabajo de evolución y biología floral ECOFLOR.

Picó FX, Bosch J (2005) Resumen de la II reunión del grupo de trabajo de evolución y biología floral ECOFLOR. Ecosistemas 2005/2.

Effects of temperature on Osmia lignaria (Hymenoptera: Megachilidae) prepupa-adult development, survival, and emergence.

Kemp WP, Bosch J (2005) Effects of temperature on Osmia lignaria (Hymenoptera: Megachilidae) prepupa-adult development, survival, and emergence. Journal of Economic Entomology 98: 1917-1923.

Assessing chronic and acute toxicity of five fungicides to Osmia lignaria and Apis mellifera.

Ladurner E, Bosch J, Kemp WP, Maini S (2005) Assessing chronic and acute toxicity of five fungicides to Osmia lignaria and Apis mellifera. Apidologie 36: 449-460.

The contribution of solitary bees to crop pollination: from ecosystem service to pollinator management.

Bosch J (2005) The contribution of solitary bees to crop pollination: from ecosystem service to pollinator management. Primeras Jornadas de Polinización en plantas hortícolas. Almería. pp. 151-165.

Assessing delayed and acute toxicity of five formulated fungicides to Osmia lignaria Say and Apis mellifera

Ladurner E., Bosch J., Kemp W.P., Maini S. (2005) Assessing delayed and acute toxicity of five formulated fungicides to Osmia lignaria Say and Apis mellifera. Apidologie. 36: 449-460.
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Doi: 10.1051/apido:2005032

Resum:

The delayed and acute toxicity of benomyl (Benlate®), captan (Captan 50WP), iprodione (Rovral®), propiconazole (Orbit™), and neem oil (Trilogy®) to two crop pollinators, A. mellifera and O. lignaria, was evaluated. Survival after contact and oral single exposure to high doses of the pesticides was compared to survival of controls with the dosing vehicle. LD 50 values at 24, 48 and 72 h from exposure were determined. Contact and oral exposure to benomyl and iprodione did not affect survival of any of the two species. Contact exposure to neem oil affected survival of A. mellifera. Orally administered propiconazole showed delayed and acute toxicity to both species. Captan severely limited survival of O. lignaria. The tested fungicides seemed to be safe to both bee species at the recommended rates, with the exception of captan to O. lignaria. To our knowledge, this is the first complete contact and oral toxicity test on an Osmia species. © INRA/DIB-AGIB/ EDP Sciences, 2005.

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Evaluation of a standard artificial flower design to feed individual bees known amounts of pesticides

Ladurner E., Bosch J., Kemp W.P., Maini S. (2005) Evaluation of a standard artificial flower design to feed individual bees known amounts of pesticides. Apidologie. 36: 379-387.
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Doi: 10.1051/apido:2005025

Resum:

We investigated the possibility of feeding individual bees known amounts of pesticides on a standard artificial flower with or without scent. We tested experienced and naive (without foraging experience) Osmia lignaria and Megachile rotundata females, and experienced Apis mellifera foragers, and trained (exposed to the artificial flower for 24 h) and untrained individuals of the three species. We also fed untrained individuals of all three species with feeding units made with natural flowers (Ladurner et al., Apidologie 34 (2003) 597-602). Feeding success on artificial flowers was lower (0-50%) for O. lignaria and M. rotundata, than A. mellifera (70-97%). Training improved feeding success in O. lignaria and A. mellifera, but not M. rotundata. Experience improved feeding success in O. lignaria, but not M. rotundata. Scent had no effect on feeding success for any of the three species. Feeding success with the natural flower method was high for the three species (87-90%). © INRA/DIB-AGIB/ EDP Sciences, 2005.

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