Defense Response in Brazilian Honey Bees (Apis mellifera scutellata × spp.) Is Underpinned by Complex Patterns of Admixture.

In 1957, an invasive and highly defensive honey bee began to spread across Brazil. In the previous year, Brazilian researchers hoped to produce a subtropical-adapted honey bee by crossing local commercial honey bees (of European origin) with a South African honey bee subspecies (Apis mellifera scutellata; an A-lineage honey bee subspecies). The resulting cross-African hybrid honey bees (AHBs)-escaped from their enclosure and spread through the Americas. Today, AHB is the most common honey bee from Northern Argentina to the Southern United States. AHBs are much more likely to sting nest intruders than managed European-derived honey bee colonies. Previous studies have explored how genetic variation contributes to differences in defense response between European-derived honey bee and AHB. Although this work demonstrated very strong genetic effects on defense response, they have yet to pinpoint which genes influence variation in defense response within AHBs, specifically. We quantified defense response for 116 colonies in Brazil and performed pooled sequencing on the most phenotypically divergent samples. We identified 65 loci containing 322 genes that were significantly associated with defense response. Loci were strongly associated with metabolic function, consistent with previous functional genomic analyses of this phenotype. Additionally, defense-associated loci had nonrandom and unexpected patterns of admixture. Defense response was not simply the product of more A-lineage honey bee ancestry as previously assumed, but rather an interaction between A-lineage and European alleles. Our results suggest that a combination of A-lineage and European alleles play roles in defensive behavior in AHBs.

Toxicity and motor changes in Africanized honey bees (Apis mellifera L.) exposed to fipronil and imidacloprid.

This study evaluated the in vitro toxicity and motor activity changes in African-derived adult honey bees (Apis mellifera L.) exposed to lethal or sublethal doses of the insecticides fipronil and imidacloprid. Mortality of bees was assessed to determine the ingestion and contact lethal dose for 24 h using probit analysis. Motor activities in bees exposed to lethal (LD50) and sublethal doses (1/500th of the lethal dose) of both insecticides were evaluated in a behavioral observation box at 1 and 4 h. Ingestion and contact lethal doses of fipronil were 0.2316 ? 0.0626 and 0.0080 ? 0.0021 µg/bee, respectively. Ingestion and contact lethal doses of imidacloprid were 0.1079 ? 0.0375 and 0.0308 ? 0.0218 µg/bee, respectively. Motor function of bees exposed to lethal doses of fipronil and imidacloprid was impaired; exposure to sublethal doses of fipronil but not imidacloprid impaired motor function. The insecticides evaluated in this study were highly toxic to African-derived A. mellifera and caused impaired motor function in these pollinators.

Toxicity and motor changes in Africanized honey bees (Apis mellifera L) exposed to fipronil and imidacloprid

ABSTRACT This study evaluated the in vitro toxicity and motor activity changes in African-derived adult honey bees (Apis mellifera L.) exposed to lethal or sublethal doses of the insecticides fipronil and imidacloprid. Mortality of bees was assessed to determine the ingestion and contact lethal dose for 24 h using probit analysis. Motor activities in bees exposed to lethal (LD50) and sublethal doses (1/500th of the lethal dose) of both insecticides were evaluated in a behavioral observation box at 1 and 4 h. Ingestion and contact lethal doses of fipronil were 0.2316 ? 0.0626 and 0.0080 ? 0.0021 μg/bee, respectively. Ingestion and contact lethal doses of imidacloprid were 0.1079 ? 0.0375 and 0.0308 ? 0.0218 μg/bee, respectively. Motor function of bees exposed to lethal doses of fipronil and imidacloprid was impaired; exposure to sublethal doses of fipronil but not imidacloprid impaired motor function. The insecticides evaluated in this study were highly toxic to African-derived A. mellifera and caused impaired motor function in these pollinators.

Harvesting Season and Botanical Origin Interferes in Production and Nutritional Composition of Bee Pollen

ABSTRACT We aimed to evaluate the frequency of bee pollen production, its botanical origin and chemical composition when collected in different seasons. Our results indicate that higher proteins (22.80 ± 3.09%) and flavonoids (2789.87 ± 1396.00 μg 100g-1) levels were obtained in the winter season, which also showed greater pollen production (134.50 ± 35.70 grams) and predominance of the Myrtaceae family. As for spring we found high concentrations of lipids (4.62 ± 2.26%) and low ash content (2.22 ± 0.39%). Regarding the amino acid composition and vitamin C content, we found no differences between the averages throughout the seasons. Our results highlight the importance of understanding not only the botanical origin and the chemical composition of bee pollen, but also the harvesting frequency of this product by bees, so that it becomes possible to supplement the colonies in times of natural food resources shortage.

Harvesting Season and Botanical Origin Interferes in Production and Nutritional Composition of Bee Pollen.

We aimed to evaluate the frequency of bee pollen production, its botanical origin and chemical composition when collected in different seasons. Our results indicate that higher proteins (22.80 ± 3.09%) and flavonoids (2789.87 ± 1396.00 µg 100g-1) levels were obtained in the winter season, which also showed greater pollen production (134.50 ± 35.70 grams) and predominance of the Myrtaceae family. As for spring we found high concentrations of lipids (4.62 ± 2.26%) and low ash content (2.22 ± 0.39%). Regarding the amino acid composition and vitamin C content, we found no differences between the averages throughout the seasons. Our results highlight the importance of understanding not only the botanical origin and the chemical composition of bee pollen, but also the harvesting frequency of this product by bees, so that it becomes possible to supplement the colonies in times of natural food resources shortage.

Activity of Brazilian propolis against Aeromonas hydrophila and its effect on Nile tilapia growth, hematological and non-specific immune response under bacterial infection

ABSTRACT The effect of the ethanolic extract of propolis (EEP) on Aeromonas hydrophila was analyzed by determination of minimum inhibitory concentration (MIC). Then, the effects of crude propolis powder (CPP) on growth, hemato-immune parameters of the Nile tilapia, as well as its effects on resistance to A. hydrophila challenge were investigated. The CPP (0.5, 1.0, 1.5, 2.0, 2.5 and 3.0%) was added to the diet of 280 Nile tilapia (50.0 ± 5.7 g fish-1). Hemato-immune parameters were analyzed before and after the bacterial challenge. Red blood cell, hematocrit, hemoglobin, mean corpuscular volume (MCV), mean corpuscular hemoglobin concentration (MCHC), and hydrogen peroxide (H2O2) and nitric oxide (NO) were evaluated. The MIC of the EEP was 13% (v/v) with a bactericidal effect after 24 hours. Growth performance was significantly lower for those fish fed diets containing 2.5 and 3% of CPP compared to the control diet. Differences in CPP levels affected fish hemoglobin, neutrophils number and NO following the bacterial challenge. For others parameters no significant differences were observed. Our results show that although propolis has bactericidal properties in vitro, the addition of crude propolis powder to Nile tilapia extruded diets does not necessarily lead to an improvement of fish health.

Activity of Brazilian propolis against Aeromonas hydrophila and its effect on Nile tilapia growth, hematological and non-specific immune response under bacterial infection.

The effect of the ethanolic extract of propolis (EEP) on Aeromonas hydrophila was analyzed by determination of minimum inhibitory concentration (MIC). Then, the effects of crude propolis powder (CPP) on growth, hemato-immune parameters of the Nile tilapia, as well as its effects on resistance to A. hydrophila challenge were investigated. The CPP (0.5, 1.0, 1.5, 2.0, 2.5 and 3.0%) was added to the diet of 280 Nile tilapia (50.0 ± 5.7 g fish-1). Hemato-immune parameters were analyzed before and after the bacterial challenge. Red blood cell, hematocrit, hemoglobin, mean corpuscular volume (MCV), mean corpuscular hemoglobin concentration (MCHC), and hydrogen peroxide (H2O2) and nitric oxide (NO) were evaluated. The MIC of the EEP was 13% (v/v) with a bactericidal effect after 24 hours. Growth performance was significantly lower for those fish fed diets containing 2.5 and 3% of CPP compared to the control diet. Differences in CPP levels affected fish hemoglobin, neutrophils number and NO following the bacterial challenge. For others parameters no significant differences were observed. Our results show that although propolis has bactericidal properties in vitro, the addition of crude propolis powder to Nile tilapia extruded diets does not necessarily lead to an improvement of fish health.

A variant reference data set for the Africanized honeybee, Apis mellifera.

The Africanized honeybee (AHB) is a population of Apis mellifera found in the Americas. AHBs originated in 1956 in Rio Clara, Brazil where imported African A. m. scutellata escaped and hybridized with local populations of European A. mellifera. Africanized populations can now be found from Northern Argentina to the Southern United States. AHBs-often referred to as 'Killer Bees'- are a major concern to the beekeeping industry as well as a model for the evolutionary genetics of colony defence. We performed high coverage pooled-resequencing of 360 diploid workers from 30 Brazilian AHB colonies using Illumina Hi-Seq (150 bp PE). This yielded a high density SNP data set with an average read depth at each site of 20.25 reads. With 3,606,720 SNPs and 155,336 SNPs within 11,365 genes, this data set is the largest genomic resource available for AHBs and will enable high-resolution studies of the population dynamics, evolution, and genetics of this successful biological invader, in addition to facilitating the development of SNP-based tools for identifying AHBs.

Action of Brazilian propolis on hematological and serum biochemical parameters of Blue-fronted Amazons (Amazona aestiva, Linnaeus, 1758) in captivity.

The present study aimed to evaluate the effect of propolis use on hematological and serum biochemical parameters in Blue-fronted Amazons (Amazona aestiva). For this, 12 adult birds were distributed randomly into individual cages, divided into treatments with different propolis levels (A = 0.0%; B = 0.5%; and C = 1.0%), in 3 distinct phases (I, II, and III), with 15-d duration for phases I and III and 30 d for phase II, totaling 60 d. In phases I and III, all birds received treatment A ration, and in phase II received A, B, or C (4 birds per treatment). At the end of each phase, blood was collected for biochemical and hematological evaluations. The variables were analyzed by ANOVA (P < 0.05). Results suggest that 0.5% propolis reduced lactate dehydrogenase levels, whereas treatment B augmented hemoglobin concentrations and eosinophil count. It is concluded that 0.5% propolis improves levels of lactate dehydrogenase, hemoglobin, and eosinophils.

Effects of Brazilian and Bulgarian propolis on bactericidal activity of macrophages against Salmonella Typhimurium.

Propolis has been used in folk medicine since ancient times due to its many biological properties, such as antimicrobial, antiinflammatory, antioxidant, immunomodulatory activities, among others. Macrophages play an important role in the early phase of Salmonella infection. In this work, macrophages were prestimulated with Brazilian or Bulgarian propolis and subsequently challenged with Salmonella Typhimurium at different macrophage/bacteria ratio. After 60 min of incubation, cells were harvested with Triton-X to lyse the macrophages. To assess the bactericidal activity, the number of colony-forming units (CFU) of S. typhimurium was determined by plating 0.1 mL in Mueller Hinton agar. After 24 h, CFU were counted, and the percentage of bactericidal activity was obtained. Propolis from Brazil and Bulgaria enhanced the bactericidal activity of macrophages, depending on its concentration. Brazilian propolis seemed to be more efficient than that from Bulgaria, because of their different chemical composition. In Bulgaria, bees collect the material mainly from the bud exudate of poplar trees, while in Brazil, Baccharis dracunculifolia DC. was shown to be the main propolis source. Our data also showed that the increased bactericidal activity of macrophages involved the participation of oxygen (H(2)O(2)) and nitrogen (NO) intermediate metabolites.