The wasps of the genus Polistes have been considered the key to understanding the evolution of social behavior in Hymenoptera. Several studies have shown that the development of organized insect societies was accompan...The wasps of the genus Polistes have been considered the key to understanding the evolution of social behavior in Hymenoptera. Several studies have shown that the development of organized insect societies was accompanied by the evolution of structures like exocrine glands, which became specialized to perform specific functions. This article investigates the ultrastructural and cytochemical features of the hypopharyngeal glands of Polistes versicolor. These glands have been studied in depth in social bees, where they occur only in nurses and produce the royal jelly. Our results＇ revealed that these glands basically did not vary among individuals or between sexes. They are constituted by spherical cells, each with a large nucleus and well-developed rough endoplasmic reticulum. Secretion vesicles are abundant, but lipid droplets were not observed, indicating that these glands may not have a role in pheromone synthesis. Acid phosphatase was detected in lysosomes, and also flee in the cytosol, but did not seem to be related with cell death. Thus, our results suggest that the hypopharyngeal glands ofP. versicolor may not have a specialized social role, but could produce digestive enzymes.展开更多
Propolis collected by stingless bees from various types of plants has been used as an antimicrobial agent in several previous studies. We assessed the effect of propolis produced by a stingless bee, Trigona apicalis, ...Propolis collected by stingless bees from various types of plants has been used as an antimicrobial agent in several previous studies. We assessed the effect of propolis produced by a stingless bee, Trigona apicalis, on Apis florea experimentally infected with Nosema ceranae, a parasite of honeybees. For parasite inoculation each Nosema free-bee was fed 2μL of 50% （w/v） sucrose solution containing N. ceranae spores at 40,000 spores/bee and 0 as a negative control （CO）. Treated bees were provided with 0%, 10%, 20% and 50% propolis （w/v） in water, defined as 0P, 10P, 20P and 50P, respectively. We assessed the effects of propolis 14 days post inoculation. All propolis-treated bees had significantly higher survival than untreated bees. However, survival of Nosema-inoculated bees was lower than that of control bees. Bees treated with the highest propolis concentration （50P） had the highest survival ratio. No control bees became infected over the course of the study. However, N. ceranae infection rates of bees treated with 0P, 10P, 20P and 50P were 75 ± 1.4%, 72 ± 5.6%, 69± 4.2% and 47± 1.4%, respectively. In addition, propolis-treated bees had hypopharyngeal gland protein content that was significantly higher than 0P and CO bees. Overall, propolis treatment significantly reduced N. ceranae infection rate and bee mortality and was associated with increased hypopharyngeal gland protein concentration.展开更多
文摘The wasps of the genus Polistes have been considered the key to understanding the evolution of social behavior in Hymenoptera. Several studies have shown that the development of organized insect societies was accompanied by the evolution of structures like exocrine glands, which became specialized to perform specific functions. This article investigates the ultrastructural and cytochemical features of the hypopharyngeal glands of Polistes versicolor. These glands have been studied in depth in social bees, where they occur only in nurses and produce the royal jelly. Our results＇ revealed that these glands basically did not vary among individuals or between sexes. They are constituted by spherical cells, each with a large nucleus and well-developed rough endoplasmic reticulum. Secretion vesicles are abundant, but lipid droplets were not observed, indicating that these glands may not have a role in pheromone synthesis. Acid phosphatase was detected in lysosomes, and also flee in the cytosol, but did not seem to be related with cell death. Thus, our results suggest that the hypopharyngeal glands ofP. versicolor may not have a specialized social role, but could produce digestive enzymes.
文摘Propolis collected by stingless bees from various types of plants has been used as an antimicrobial agent in several previous studies. We assessed the effect of propolis produced by a stingless bee, Trigona apicalis, on Apis florea experimentally infected with Nosema ceranae, a parasite of honeybees. For parasite inoculation each Nosema free-bee was fed 2μL of 50% （w/v） sucrose solution containing N. ceranae spores at 40,000 spores/bee and 0 as a negative control （CO）. Treated bees were provided with 0%, 10%, 20% and 50% propolis （w/v） in water, defined as 0P, 10P, 20P and 50P, respectively. We assessed the effects of propolis 14 days post inoculation. All propolis-treated bees had significantly higher survival than untreated bees. However, survival of Nosema-inoculated bees was lower than that of control bees. Bees treated with the highest propolis concentration （50P） had the highest survival ratio. No control bees became infected over the course of the study. However, N. ceranae infection rates of bees treated with 0P, 10P, 20P and 50P were 75 ± 1.4%, 72 ± 5.6%, 69± 4.2% and 47± 1.4%, respectively. In addition, propolis-treated bees had hypopharyngeal gland protein content that was significantly higher than 0P and CO bees. Overall, propolis treatment significantly reduced N. ceranae infection rate and bee mortality and was associated with increased hypopharyngeal gland protein concentration.
