Osmia bees (Hymenoptera: Megachilidae) are pollinating insects that are becoming more widely used in agriculture. They are solitary and univoltine bees, and have a strong sexual dimorphism. These insects have the maximum of fly and foraging activities in the early spring and are active even in adverse weather conditions and very low temperatures (5-8°C), that are forbidding for the Apis mellifera. The agricultural interest in using Osmia bee as pollinator derives from these characteristics. In this investigation the two non-protein amino acids beta-Alanine and gamma-Amino Butyric Acid (GABA) are used as nectar compounds to observe the Osmia bees behaviour. Two species of Osmia, O. cornuta (Latreille, 1805) and O. bicornis (Linnaeus, 1758), were reared in plexiglass tubes as boxes, closed with a metallic net. Each rearing tube had three 0.8 ml Eppendorf plastic vials containing the diet inserted in an artificial flower, 7 plastic test tubes and some pieces of soft white paper. Three diets were tested, each on 5 female Osmia bees: control diet (sucrose 20% w/v), sugar syrup with beta-Alanine 46 mM and sugar syrup with GABA 15 mM (amino acids concentration 20 times higher than in natural nectar). Five parameters were observed randomly for 5 minutes each time for all the life span of the reared bees: 1) how many bees were localized on the metallic nets, 2) on the artificial flower, 3) under the paper, 4) how many remained in the test tubes and 5) how many flew. One trial for O. cornuta and two for O. bicornis were carried out. Results showed a significant survival rate increase for the Osmia bees reared with the GABA diet compared to the other diets. Concerning the control diet, more Osmia bees stayed in the test tubes and under the paper, while Osmia bees from the rearing box with a GABA diet had a significant increase of the parameters of motility (flight and localization on the net). This investigation was mainly focused on the identification of a proper methodology and of valid parameters to study the effect of nectar compounds on the solitary bees behavior. Although further investigations could be made to perfect this type of ethological studies, results showed that the observed parameters and the methodology used for Osmia bees rearing seem to be an effective method.
Monitoring of Osmia bees reared with beta-Alanine and gamma-Amino Butyric Acid diets
GALLONI, MARTA;BOGO, GHERARDO;
2014
Abstract
Osmia bees (Hymenoptera: Megachilidae) are pollinating insects that are becoming more widely used in agriculture. They are solitary and univoltine bees, and have a strong sexual dimorphism. These insects have the maximum of fly and foraging activities in the early spring and are active even in adverse weather conditions and very low temperatures (5-8°C), that are forbidding for the Apis mellifera. The agricultural interest in using Osmia bee as pollinator derives from these characteristics. In this investigation the two non-protein amino acids beta-Alanine and gamma-Amino Butyric Acid (GABA) are used as nectar compounds to observe the Osmia bees behaviour. Two species of Osmia, O. cornuta (Latreille, 1805) and O. bicornis (Linnaeus, 1758), were reared in plexiglass tubes as boxes, closed with a metallic net. Each rearing tube had three 0.8 ml Eppendorf plastic vials containing the diet inserted in an artificial flower, 7 plastic test tubes and some pieces of soft white paper. Three diets were tested, each on 5 female Osmia bees: control diet (sucrose 20% w/v), sugar syrup with beta-Alanine 46 mM and sugar syrup with GABA 15 mM (amino acids concentration 20 times higher than in natural nectar). Five parameters were observed randomly for 5 minutes each time for all the life span of the reared bees: 1) how many bees were localized on the metallic nets, 2) on the artificial flower, 3) under the paper, 4) how many remained in the test tubes and 5) how many flew. One trial for O. cornuta and two for O. bicornis were carried out. Results showed a significant survival rate increase for the Osmia bees reared with the GABA diet compared to the other diets. Concerning the control diet, more Osmia bees stayed in the test tubes and under the paper, while Osmia bees from the rearing box with a GABA diet had a significant increase of the parameters of motility (flight and localization on the net). This investigation was mainly focused on the identification of a proper methodology and of valid parameters to study the effect of nectar compounds on the solitary bees behavior. Although further investigations could be made to perfect this type of ethological studies, results showed that the observed parameters and the methodology used for Osmia bees rearing seem to be an effective method.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
