Africanized Honey Bees Research Articles

Africanized honey bee colonies in Costa Rica: first evidence of its management, brood nest structure and factors associated with varroa mite infestation.

Management, brood nest structure and factors associated with varroa mite infestation were studied in 60 apiaries of Africanized honey bees in the northwest region of the Central Valley of Costa Rica. Apiaries were monitored two times. The first monitoring was taken forward during the rainy season between May and November 2019. The second monitoring during the dry season between February and March 2020. Information about the beekeepers, apiaries and management was collected through a survey. Amount of open and capped brood, honey and pollen were measured in the field. The infestation rate of varroa (IRV) was quantified using standard laboratory methods. A determination of multi-residue pesticides in bee bread was made through GC-MS/MS and LC-MS/MS techniques. According to the results, most of the beekeepers produce honey (96.7%), participate in training activities (82.2%), and change the bee queens annually (70%). The first monitoring was characterized by a lower amount of capped brood and honey reserves compared to the second one. IRV was significantly higher in the first monitoring (6.0 ± 0.4) in comparison with the second one (3.0 ± 0.3) (U Mann-Whitney p < 0.001). The maximum value for the first monitoring exceeds 40%, while this value was close to 25% in the second monitoring. Mite infestation exposed significant differences in relation to the variables associated to the beekeeper's management, i.e., change of bee queen (p = 0.002) or when beekeepers monitor varroa mites (p = 0.004). Additionally, the IRV had inverse correlations (p < 0.01) with the number of comb sides with capped brood (Spearman's rho coefficient = -0.190), and honey reserves (Spearman's rho coefficient = -0.168). Furthermore, 23 of 60 bee bread samples presented one to five pesticide residues, being the most frequent antifungal agrochemicals.

The effect of diet on the development of pheromone signals in Apis mellifera scutellata workers

The social organization of honey bee colonies is predominantly controlled by the pheromonal cues produced by the queen, workers and brood. Pheromone composition is dependent on the social environment, context, audience and physiological status of the individual. In the absence of the queen, ontogenic changes and reproductive status modulate pheromone production and composition in workers. In these queenless workers, pheromonal status influences diet with dominant workers consuming less pollen than subordinates as they are fed protein jelly through trophallaxis, which positively correlates with their ovarian activation. However, it is not known to what extent diet affects pheromonal status in queenless workers. To investigate whether diet affects the production of glandular signals, Apis mellifera scutellata workers were fed carbohydrate-only or protein-rich diets for twenty-five days. The mandibular and tergal gland secretions were analyzed using gas chromatography and the ovarian activation statuses were evaluated. A clear link between diet and pheromone profiles was observed with workers fed a protein-rich diet producing mandibular gland chemical profiles more typical of queens. The effect of diet on tergal gland chemical profiles was less distinct, but a shift from fatty acid to n-alkane components was seen in the older workers irrespective of diet, most likely due to ontogeny. Though mandibular gland profiles were queen-like with high proportions of 9-HDA, the levels of 9-ODA remained in the range of non-reproductive workers and the ovaries were not fully activated. This suggests that diet could prime queenless workers to become false queens, but do not trigger the transformation into false queens.

A Hitchhiker’s Ride: The Honey Bee Louse Braula Coeca (Diptera: Braulidae) Selects its Host by Eavesdropping

The bee louse Braula spp. had until recently a distribution coincident with its host the honey bee. The adult fly usually attaches to a worker honey bee and steals food from its mouth. However, not all worker bees carry Braula spp. and the mechanism used by Braula spp. to select hosts is not well understood. Using choice remounting bioassays and chemical analyses, we determined host selection and the cues used by B. coeca, a species associated with the African honey bee Apis mellifera scutellata. Braula coeca successfully remounted bees from which they were initially removed and preferred their mandibular gland pheromones (MDG) over those of bees not carrying them. The bee lice did not show any preference for the cuticular hydrocarbons of both types of workers. Chemical analyses of the MDG extracts, revealed quantitative differences between the two categories of workers, with workers carrying B. coeca having more of the queen substance (9-oxo-2(E)-decenoic acid) and worker substance (10-hydroxy-2(E)-decenoic). Braula coeca showed a dose response to the queen substance, indicating its ability to use host derived kairomones as cues that allowed it to benefit from trophallactic dominance by individuals that have a higher probability of being fed by other workers.

Daily activity rhythm of the African stingless bee Hypotrigona gribodoi (Hymenoptera: Meliponini) in the dry season, with notes on nest structure and colony composition

We studied 18 colonies of Hypotrigona gribodoi (Magretti) nesting in the tubing of a disused horticultural sprinkler system during the late dry season in Ghana, West Africa. Flight activity began around dawn (about 06:00), rising to a peak in the half-hour starting 07:30 and gradually declining to end around dusk (about 18:00). Bees returning with pollen showed a more extended peak from 07:30 to 09:00. Dissection of 18 nests showed a mean inner volume of 466.5 ml, while 17 active colonies had a mean number of 851 adults. Colony size is positively correlated with nest size. It is likewise positively correlated with the fraction of fully mature adult females. Several nests had branching entrance tubes with an angle of roughly 30⁰ between branches. In each of three such nests studied, there was a marked division in the use of the two branches, such that one served mainly as an exit and the other as an entrance.

Aggressive dominance of acacia floral resources by wild east African lowland honey bees

AbstractThe East African lowland honey bee (Apis mellifera scutellata) is reported as an aggressive subspecies of the Western honey bee, but few studies have investigated the impact of its aggressiveness on other insect pollinators. Observations of flower visitors to Vachellia (Acacia) etbaica and interactions between honey bees and other insects were conducted in 2022 in Mpala, Kenya. A total of 873 individual flower visitors were recorded, the most frequent being Hymenoptera, followed by Diptera and Lepidoptera. Honey bees dominated floral resources in the morning and late afternoon. When honey bees encountered other types of insects, they displaced the latter from flowers 100% of the time. This has never been observed in other Western honey bee subspecies, and we recommend further research on these taxa.

Fine‐scale bee species distribution models: Hotspots of richness and endemism in South Africa with species‐area comparisons

Abstract While global patterns of bee diversity have been modelled, our understanding of fine‐scale regional patterns is more limited, particularly for under‐sampled regions such as Africa. South Africa is among the exceptions on the African continent; its bee fauna (ca. 1253 species) has been well collected and documented, including mass digitising of its natural history collections. It is a region with high floral diversity, high habitat heterogeneity and variable rainfall seasonality. Here, we combine a South African bee species distributional database (877 bee species) with a geospatial modelling approach to determine fine‐scale (~11 × 11 km grid cell resolution) hotspots of bee species richness, endemism and range‐restricted species. Our analyses, based on the probabilities of occurrence surfaces for each species across 108,803 two‐minute grid cells, reveal three bee hotspots of richness: Winter rainfall, Aseasonal rainfall and Early‐to‐late summer rainfall. These hotspots contain large numbers of endemic and geographically restricted taxa. Hotspots with particularly high bee diversity include the Fynbos, Succulent Karoo and Desert biomes; the latter showing 6–20 times more species per unit area than other biomes. Our results conform with global species‐area patterns: areas of higher‐than‐expected bee density are largely concentrated in Mediterranean and arid habitats. This study further enhances our knowledge in identifying regional and global hotspots of richness and endemism for a keystone group of insects and enabling these to be accounted for when setting conservation priorities.

Viruses, microsporidia and glyphosate residues in Africanized honey bees Apis mellifera, under field conditions

Bees are affected by several factors, including pathogens and pesticides, which may cause mortality and consequent population decline. Considering the ecological and economic importance of these pollinators, this study evaluated the occurrence of the microsporidia Nosema apis and Nosema ceranae, the viruses ABVP, DWV, BQCV, KBV, IAPV and CBPV and residues of the pesticides atrazine, chlorantraniliprole, deltamethrin, fipronil and glyphosate in workers from field colonies of Africanized honey bee Apis mellifera across one year. The presence of pesticide residues was also evaluated in honey and pollen samples. All tested viruses were found in the workers, with BQCV showing the highest copy number. BQCV levels were correlated with relative humidity. Nosema ceranae was the only microsporidian with higher intensities of infection during summer and autumn; seasons with high availability of food resources, which can act as dispersers of this pathogen. Small amounts of glyphosate and its metabolite were detected in the bees tested. These data show that honey bees are contaminated with pathogens and pesticides in the field and present correlative data for these threats.

The Varroa paradox: infestation levels and hygienic behavior in feral scutellata-hybrid and managed Apis mellifera ligustica honey bees

The Varroa destructor mite is a parasitic threat to managed and feral honey bee colonies around the world. Beekeepers use miticides to eliminate Varroa in commercial hives, but these chemicals can diminish bee health and increase miticide resistance. In contrast, feral honey bees have developed multiple ways to counteract mites without chemical treatment. We compared mite levels, grooming habits, and mite-biting behavior between feral Africanized honey bees (genomically verified Apis mellifera scutellata hybrids) and managed Italian honey bees (A. mellifera ligustica). Surprisingly, there was no difference in mite infestation levels between scutellata-hybrids and managed bees over one year despite the regular use of miticides in managed colonies. We also found no differences in the social immunity responses of the two groups, as measured by their hygienic habits (through worker brood pin-kill assays), self-grooming, and mite-biting behavior. However, we provide the first report that both scutellata-hybrids and managed honey bees bite off mite chemosensory forelegs, which the mites use to locate brood cells for reproduction, to a significantly greater degree than other legs (a twofold greater reduction in foreleg length relative to the most anterior legs). Such biting may impair mite reproduction.

Land use and occupation and pesticide contamination assessment in honey from Africanized honey bees (Hymenoptera: Apidae) using gas chromatography-mass spectrometry.

We examined pesticide contamination in honey from Africanized honey bees in two different seasons, and evaluated the concentration and incidence of these compounds in georeferenced apiaries to provide relevant information for food safety and environmental quality. The land use and occupation of the region were evaluated by selecting 15 apiaries and georeferencing three randomly selected colonies of Africanized honey bees within each apiary. Honey samples were collected during two seasons, and three organochlorine pesticides (p.p`-DDE, Mitotane and Bicyclo[2.2.1]) and four organophosphate pesticides (Ethoprophos, Methyl Parathion, Chlorpyrifos and Fenchlorphos) were analyzed in the honey using gas chromatography-mass spectrometry. 80% of the apiaries showed a predominance of agricultural land use in the foraging areas of the bees. There was a higher concentration of pesticides in samples collected during Season I compared to Season II. There were differences in the proportion of samples contaminated with pesticides between seasons. Some honey samples showed concentrations of the chlorpyrifos pesticide above the levels recommended by Brazilian legislation. Pesticide contamination of honey is not limited to specific application season, indicating the persistent presence and easy availability of pesticides, including banned pesticides not sold or prescribed by agronomists, potentially smuggled from neighboring countries.

Protein supplementation of Africanized honey bee colonies improves drone and semen quality

Protein supplementation of Africanized honey bee colonies improves drone and semen quality

Comparative study of the performance of africanized bees managed in thermal stress and thermal comfort in a semiarid region

Comparative study of the performance of africanized bees managed in thermal stress and thermal comfort in a semiarid region

Genetic Diversity of West African Honey Bee (Apis ‎mellifera adansonii Latreille, 1804) from Rural and Urban ‎Areas of ‎Kwara State, North-Central Nigeria

Over one third of the world’s crops– including fruits, vegetables, nuts, spices, and oilseed–‎require insect pollination, and human reliance on ‎pollination services by honey bees (Apis ‎mellifera) to promote these crops continues to rise due to increasing demands from growing ‎human ‎populations. Identifying the effects of urbanization on genetic diversity on this ‎pollinating insect is important in the field of bioscience. This study aimed to investigate genetic diversity of A. mellifera in Kwara State, Nigeria, using the random amplified polymorphic DNA (RAPD) marker. ‎Thirty honey bees ‎were simultaneously collected from both rural and urban regions in ‎Kwara state, Nigeria. Samples were morphologically identified using ‎standard methods, ‎genomic DNA isolated and amplified using five RAPD primers. Data collected were ‎analysed using PyElph, ‎ARLEQUIN, and GeneAlEx version 6.501 software. The results ‎showed that the DNA fragment sizes produced per primer varied from 200 to ‎‎3000 bp. Percentages of polymorphic loci amplified by each primer varied from 17.33 to 33.33%. ‎Analysis of unbiased Nei genetic ‎distance values showed that Agbede (rural) and Adewole ‎‎(urban) showed the highest value of unbiased genetic distance (0.073), while ‎Amoyo ‎‎(rural) to Idofian (urban) exhibited the lowest value (0.027). Dendrogram analysis revealed ‎genetically close relationships among the sampled ‎A. mellifera‎ populations. The low level of genetic ‎polymorphisms observed among the honey bee populations in the two ‎regions ‎indicated that there is genetic relatedness among them. This study concluded that RAPD ‎marker is a useful method for ‎understanding population genetic structure of the African honey ‎bees. These results can be used as baseline information for future genetic ‎diversity ‎assessment of honey bees in Nigeria with larger samples. It is therefore recommended that ‎there is a need to safeguard the genetic ‎diversity of A. mellifera‎ to prevent extinction or ‎gradual loss of diversity‎‎‎.

Defensive Behaviors of the Central Highland Honeybees, Apis mellifera bandasii against Varroa destructor in Ethiopia

The parasitic mite V. destructor has caused long-lasting losses to the survival of European honeybee colonies. In contrast, African honeybees are likely capable of surviving the effects of this parasitic mite with varying defense mechanisms. This study provides insights into two defense behavioral traits, including hygienic and grooming behaviors of local honeybee, Apis mellifera bandasii colonies against V. destructor mite in Ethiopia. Hygienic behavior (HB) was evaluated using the standard pin-killed brood method by calculating the dead brood removal rates (%) at 24 and 48 hrs. While grooming behavior (GB) was assessed by measuring the number of daily fallen mites and the percentage of damaged mites. The results of hygienic behavior showed greater brood removal rates of 83.1±14.3% and 97.6±3.4% at 24 hrs and 48 hrs, respectively. There were strong negative correlations between the HB and Varroa infestation rates, indicating that HB has the potential to reduce the mite population in colonies. Grooming behavior also showed higher mean daily fallen mites per colony (16.3±10.2), of which about 80% of the total fallen mites (n=488) were damaged. Ten body damage categories were identified, with most damages inflicted on mites’ legs, dorsal shield, and gnathosoma because of the GB. Our study suggests that combined hygienic and grooming behaviors could be used as effective defenses against V. destructor infestations in A. m. bandasii colonies. Therefore, future selective breeding programs should integrate these specific host defenses in order to produce sustainable colonies resistant to this parasitic mite.

Interspecific competition between ants and African honeybees (Apis mellifera scutellata) may undermine the effectiveness of elephant beehive–deterrents in Africa

AbstractBeehive deterrents are commonly used to mitigate human–elephant conflict and protect woody vegetation. To ensure hive activity, reduce abscondment risks, and maintain deterrent effectiveness, resident bee colonies require supplementary feeding during periods of low resource availability. However, our study found that ants frequently consume the supplementary feed in open feeders intended for bees. Anoplolepis custodiens was the most numerically dominant species that excluded bees from the feeders, followed by Camponotus and Crematogaster spp. With higher ant abundance, the predicted probability of zero bees being present at feeders increased up to 82%. This competition may undermine the efficacy of beehive deterrents as a conflict mitigation tool. We developed a simple and effective ant exclusion method that raised the overall predicted probability of bees' presence at supplementary feeding stations from 32% to 68%. Our findings suggest that innovative solutions to exclude ants from supplementary feed may improve the implementation and success of this conflict mitigation method across Africa.

The Longevity Of Africanized Apis mellifera L. Influenced By Synthetic Phytosanitary Products Used In Soybean

Honey bees are the main pollinators, but they are in decline and synthetic phytosanitary products (SSPs) are suspected to be related. Therefore, this study aimed to evaluate the effect of three commercial SPPs, used to control the stink bug in soybean, formulated with Acetamiprid + Alpha-cypermethrin; Imidacloprid + Beta-Cyfluthrin and Fenitrothion + Esfenvalerate, on adult worker Africanized Apis mellifera. For this, worker honey bees was exposed to SPPs through three bioassays: 1) sprayed on the bees, 2) sprayed on Petri dishes in which the bees was subsequently placed, and 3) mixed with the Candy paste supplied to the bees. The honey bees in bioassay 3 had their midgut submitted to histopathological analysis. All bioassays was maintained in a climatized room (34 ± 2ºC, RH 60 ± 5%) and the workers longevity was verified at 1 up to 120 hours. In bioassay 1 at the time of 6 hours evaluation, 100% of the bees of all the SPPs was dead. In bioassay 2 all bees was dead after two hours of exposure of the three SPP. In bioassay 3 the SPP1 and SPP2 caused 100% mortality after 60 hours of exposure, to theSPP3 all bees was dead after 96 hours, while for the control, after 96 hours only 45% of the bees were dead. Histological analysis revealed the destruction of the midgut cells of all workers from the three SPPs treatments. The three evaluated SPPs showed no selectivity for A. mellifera workers, reducing bee longevity.

Supplemental feeding coupled with different grafting techniques ensures better quality of queen honey bees

The quality of queens (Apis mellifera L.) is essential for the maintenance and development of A. mellifera honey bee colonies and can be obtained in several ways. However, a combination of different techniques can facilitate this process. This research was carried out to evaluate the Africanized honey bee queen production with the supply of fermented and unfermented additives using the techniques of single and double larvae grafting through assessment of morphometric characteristics, ovarian histology and supplement consumed by colonies. The queens were produced in 30 colonies: one group without supplemental feeding, one with fermented, and one with non-fermented supplemental feeding, with two grafting techniques. The use of unfermented supplements and the double grafting technique improved the quality of queen honey bees (p < 0.05). Also, the highest supplement consumption occurred when colonies were stimulated to produce queens. Therefore, the results shown herein are relevant for improving production processes and the quality of queen bees.

On the subgeneric placements of Ceratina foveifera Strand and C. labrosa Friese from Africa (Hymenoptera: Apidae)

Two new subgenera are established for enigmatic species of African small carpenter bees, genus Ceratina Latreille (Xylocopinae: Ceratinini). Ceratina foveifera Strand is most similar to Copoceratina Terzo &amp; Pauly but differs in integumental coloration and sculpturing and absence of supraclypeal ridges, and is here classified in Xestoceratina subgen. n. Ceratina labrosa Friese is similar to Ceratina s. str. and Euceratina Hirashima, Moure, &amp; Daly but differs by the structure of the metasomal terga and male genitalia, and is placed in Alloceratina subgen. n.

Protecting the resource: an assessment of mitigation methods used to protect large trees from African elephant impact in a savanna system

African elephants Loxodonta africana can alter the structural components of savanna ecosystems, often through the reduction of the large tree (≥ 5 m height) cover component. Elephant impact can be amplified in small, protected areas, or areas where water is readily available to elephants. One management option is to protect large trees directly using applied mitigation methods to limit elephant impact. In this paper, we assessed and compared the effectiveness and logistical requirements of four mitigation methods that have been applied to protect large trees from elephant impact in South Africa's Greater Kruger National Park – namely African honeybees Apis mellifera scutellata in beehives; creosote oil in glass jars, concrete pyramids arranged in circles around trees, as well as wire‐netting the trees' main stems. For each method, elephant impact levels and tree mortality rates were measured over a 2–5‐year period depending on the method in use. Sample sizes ranged from 43 to 59 trees per mitigation method, with a comparable control, which was a tree of the same species and morphological dimensions but lacking any mitigation application. Beehives were the most effective method at reducing tree loss, significantly reducing tree mortality from 34% (6.8%/year) in control trees to only 10% (2% year‐1) over the five‐year experimental period. However, beehives were the most expensive method to apply to a tree, although this cost can be compensated through honey sales. Concrete pyramids reduced tree loss when the combined pyramid radius was &gt; 1.5 m in length, whilst wire‐netting was effective against bark‐stripping by elephants but was still vulnerable to heavier forms of impact such as uprooting and stem snapping. Creosote jars did not prevent elephants from impacting treated trees. Our results provide managers with a toolkit for protecting large trees against elephant impact, commenting on both the efficacy and the logistical constraints for each method.

Lactobacillus kunkeei impacts the health of honey bees, Apis mellifera scutellata, and protects the bees against the opportunistic pathogen Serratia marcescens

Lactobacillus kunkeei impacts the health of honey bees, Apis mellifera scutellata, and protects the bees against the opportunistic pathogen Serratia marcescens

Differences in the suitability of published honey bee (Apis mellifera) reference genes between the African subspecies Apis mellifera scutellata and European derived Apis mellifera.

Quantitative real-time polymerase chain reaction (qPCR) is a method widely used to determine changes and differences in gene expression. As target gene expression is most often quantified relative to the expression of reference genes, the validation of suitable reference genes is of critical importance. In practice, however, such validation might not be thoroughly conducted if the same species and the same tissue or body parts are used for qPCR experiments. Here we show, that qPCR reference genes published for workers of European honey bee (Apis mellifera) subspecies fail to be stably expressed in workers of the African subspecies Apis mellifera scutellata. This is the case even when the sampled workers are in the same life stage, the same organ was dissected and the same reagents were used. Thus, reference genes need to be thoroughly re-tested before they can be used as suitable references even when the only thing that changes is the subspecies used.