Nesting ecology of stingless bees and potential threats to their survival within selected landscapes in the northern Volta region of Ghana

Stingless bees are key insects in the tropics, both as pollinators of crops and as contributors to the maintenance of floral diversity through pollination of wild plants. This study investigated the nesting ecology and threats to three stingless bee species: Meliponula bocandei (Spinola), Meliponula ferruginea (Lepeletier) and Dactylurina staudingeri (Gribodo) in three landscapes characterized as forest with logging and wild honey hunting; farmlands that experience annual wild fires and a national park. The study was carried out in July 2011 and February 2012. A total of 93 stingless bee nests were found in 48 ha (density 1.9 nests per ha), 81% in tree cavities and 19% in deserted termite mounds and in the ground. M. ferruginea was the only species using deserted termite mounds (seventeen nests) and in the ground (1 nest). Although tree size (diameter at breast height, DBH >15 cm) and density of large tree were important for nest site selection, there was no influence of tree species. M. bocandei may be restricted in choice of nest site in farmland areas by the absence of trees. Reduced availability of trees in agricultural landscape together with bush burning and wild honey collecting is the main threats to stingless bees survival and abundance which need to be addressed for their successful conservation in Ghana.     

PVC nest boxes are less at risk of occupancy by feral honey bees than timber nest boxes and natural hollows

Feral European Honey Bee (Apis mellifera) has been identified as a potential nest competitor for Australian hollow nesting species, but few studies have investigated the impact of feral honey bee competition on Threatened species. Our study used data from Glossy Black‐cockatoo (Calyptorhynchus lathami halmaturinus) nests on Kangaroo Island, monitored and managed over an 11‐year period, and found 12% of nests became occupied by feral honey bees during that period. Our results indicate that feral honey bees were less likely to occupy nest boxes made of PVC (5%) compared with wooden nest boxes (24%) or natural hollows in Eucalyptus trees (14%). The removal of feral honey bee hives from nests is a priority for long‐term conservation of glossy black‐cockatoos on Kangaroo Island. We recommend that PVC nest boxes are chosen for future nesting habitat restoration, due to the more frequent use of wooden nest boxes by feral honey bees.     

A push‐pull integrated pest management scheme for preventing use of parrot nest boxes by invasive Africanized honey bees

Africanized honey bees (Apis mellifera scutellata) compete with endangered parrots for nest boxes and can hamper conservation efforts. We tested an integrated pest management push‐pull protocol in the Atlantic Forest in São Paulo, Brazil, in an effort to prevent bee swarms from colonizing nest boxes (N = 30 in the forest plus five in aviaries) meant for use by Vinaceous‐breasted Amazons (Amazona vinacea). Fifteen parrot nest boxes were treated with a permethrin insecticide to “push” scout bees away and each parrot box was paired with a bee trap box containing a pheromone lure to “pull” bees. Over a 1‐yr period (March 2013 to March 2014), 29 insect colonies moved into 18 of the 35 trap boxes. Nine Africanized honey bee, three native Jatai bee (Tetragonisca sp.), and 17 wasp colonies occupied trap boxes. Only one experimental push‐pull pair untreated parrot box was invaded by bees and no parrot boxes in aviaries were colonized. Four of the parrot nest boxes were occupied by birds during our study. Although none were used by Vinaceous‐breasted Amazons, Southern House Wrens (Troglodytes musculus), Green‐winged Saltators (Saltator similis), and Plain Parakeets (Brotogeris tirica) nested in the boxes and all nests were successful. Although long‐term studies are needed before drawing conclusions about the effectiveness of trap boxes, our results suggest that a push‐pull protocol may prove useful for reducing the use of nest boxes meant for parrots and other cavity‐nesting birds by Africanized honey bees and other insects.     

Do feral honey bees (Apis mellifera) and regent parrots (Polytelis anthopeplus) compete for nest sites?

Abstract Surveys of nesting sites of feral honey bees (Apis mellifera) and regent parrots (Polytelis anthopeplus) were made in the red gum/black box woodlands of Wyperfeld National Park, Victoria, Australia. Data on tree species and size, and number of hollows were collected from all trees within seven 500 × 100m plots. Nest site characteristics were quantified for both bees and parrots. We found 27 feral honey bee colonies, suggesting a density of 77.1 colonies per km². The average occupation rate for bees was 1.3% of trees and 0.7% of available hollows. The height, aspect and entrance characteristics of honey bee nests at Wyperfeld were not qualitatively different to those reported elsewhere. We found 15 pairs of nesting regent parrots. Nest sites chosen by these birds overlapped those chosen by honey bees, but 52% of bee nests were in cavities unsuitable for regent parrots. We suggest that honey bee population growth may be limited in the park by a lack of water.     

Task-partitioned nectar transfer in stingless bees: work organisation in a phylogenetic context

Abstract 1. The eusocial corbiculate bee tribes comprise the Apini (honey bees), Bombini (bumble bees), and Meliponini (stingless bees). Honey bee foragers ( Apis ) transfer nectar to receiver bees within the nest. This is an example of task partitioning, in which a task is split into sub-tasks connected by material transfer. Nectar transfer does not occur in Bombini. Although it is reported in some species of Meliponini, it has not been subject to detailed study.
2. Nectar transfer was investigated in five genera of Meliponini from Yucatan, Mexico ( Melipona , Trigona , Scaptotrigona , Nannotrigona , and Plebeia ). Nectar transfer occurred in all species and for > 99% of foragers. Multiple transfer, in which a forager unloads nectar to more than one receiver, occurred but at a lower level than in Apis . In M. beecheii , multiple transfer was associated strongly with putative recruitment dances.
3. The data provide some support for the hypothesis that task partitioning is favoured by large colony size, in that the Meliponini never have small colonies because colonies are swarm founded. This ensures that colonies are always large enough to prevent delays in finding a transfer partner imposing high costs. Further tests of this hypothesis are suggested.
4. Viewed in a phylogenetic context, the most parsimonious interpretation is that nectar transfer evolved once in the clade (Apini + Meliponini).     

Subtle visits despite guards: Theft from nest of stingless bee (Meliponini) by orchid bee (Euglossini)

The theft of food items and building materials from nests of stingless bees (Hymenoptera: Apidae: Meliponini) is most commonly carried out by other Meliponini bee species, especially by those related to genus Lestrimelitta Friese, 1903. In this note, we recorded the theft of cerumen and propolis made by a species of the orchid bee, Euglossa annectans Dressler, 1982 (Apidae: Euglossini) from the nest of the stingless bee Tetragonisca angustula (Latreille, 1811). We noticed that the guard workers of T. angustula did not attack the thief bee even though it did not come sufficiently close to the entrance tube of the nest.     

Honey bee (<Emphasis Type="Italic">Apis mellifera capensis/A. m. scutellata</Emphasis> hybrid) nesting behavior in the Eastern Cape,South Africa

Little is known about the natural history of wild honey bee (Apis mellifera) colonies in the Eastern Cape Province of South Africa. The goal of this research was to examine nest site characteristics of honey bee (A. m. capensis/A. m. scutellata hybrid) colonies sampled from a variety of habitats (nature reserves, livestock farms, and an urban setting) in the Eastern Cape. We also determined how nest site location related to various colony strength parameters. In general, colonies not nesting in ground cavities tended to nest in locations >6 m high when nesting in cliffs and buildings and >2 m high when nesting in trees. Colonies typically nested in cavities whose entrances faced a southeasterly direction and were ~40 L in volume. We sampled a subset of colonies to determine the relationship between nest type and the following colony strength parameters: total area of comb in the colony, the volume of stored honey, pollen, and brood, adult bee population, the weight per adult bee, and the bee/nest cavity volume ratio. In general, colonies nesting in cliffs tended to be stronger than those nesting in the ground or trees. Our findings provide new insights into the nesting biology of honey bees in the Eastern Cape, South Africa, perhaps leading to the formation of conservation recommendations for honey bees in this region.     

Rural avenues as a refuge for feral honey bee population

Several honey bee (Apis mellifera) subspecies are in danger of local extinction because their feral population have almost completely disappeared. An important threat to the feral populations of bees is loss of habitat and loss of woodlands. In many places the only habitat suitable for honey bee nesting are rows of trees along roadsides. We studied a feral population of honey bees inhabiting avenues in northern Poland. We inspected 142 km of avenues and found 45 feral colonies. The estimated density of feral population inhabiting the avenues was 0.10 nest km^?2. Honey bees preferred to build their nests in trees with a thick trunk and a somewhat weak state of health. There was no strong preference of bees to any species of trees. We stress the importance of protection of existing avenues and creating new ones. This can provide suitable habitat not only for honey bees but also for other endangered species.     

The cuticular profiles of Australian stingless bees are shaped by resin of the eucalypt tree Corymbia torelliana

Bees are known to collect pollen and nectar to provide their larvae and themselves with food. That bees, especially the tropical stingless bees (Apidae: Meliponini), also collect plant resins has, however, been barely addressed in scientific studies on resource use in bees. Resins are used for nest construction, nest maintenance and nest defence. Furthermore, some South‐East Asian species transfer resin‐derived terpenes to their cuticular profiles. The resin requirement of bees is in turn used by certain plant species, which attract bees either for pollination by providing resin in their inflorescences, or for seed dispersal by providing resin in their seed capsules (mellitochory). Mellitochory is found in the eucalypt tree Corymbia torelliana, the resin of which is collected by Australian stingless bees. We investigated how the interaction between C. torelliana and resin‐collecting bees affects the chemical ecology of two Australian stingless bee genera by comparing the chemical profiles of eight bee species with resin from C. torelliana fruits. The two bee genera differed significantly in their chemical profiles. Similar to South‐East Asian stingless bees, 51% of all compounds on the body surfaces of the five Tetragonula species were most likely derived from plant resins. Up to 32 compounds were identical with compounds from C. torelliana resin, suggesting that Tetragonula species include C. torelliana compounds in their chemical profiles. By contrast, few or none resinous compounds were found on the body surfaces of the three Austroplebeia species sampled. However, one prominent but as yet unknown substance was found in both C. torelliana resin and the chemical profiles of all Tetragonula and four Austroplebeia colonies sampled, suggesting that most colonies (76%) gathered resin from C. torelliana. Hence, C. torelliana resin may be commonly collected by Australian stingless bees and, along with resins from other plant species, shape their chemical ecology.     

Pollination of strawberry by the stingless bee,Trigona minangkabau,and the honey bee,Apis mellifera: An experimental study of fertilization efficiency

To know basic information about the stingless bee, Trigona minangkabau, and the European honey bee, Apis mellifera, as pollinator of strawberry, we set three greenhouse areas: the honey bee introduced area, the stingless bee introduced area and the control area. Foraging and pollination efficiencies of the two bee species were studied comparatively. During the experimental period (10 days), the stingless bee foraged well and the nest weight did not change, though the honey bee often foraged inefficiently and the nest weight decreased by 2 kg. The average nectar volume of a flower was lower in the honey bee area (0.02 μl) and nearly the same in the other two areas (0.1 μl). We make a numerical model to describe pollination and fertilization process. This model shows that one visit of the honey bee pollinated 11% of achenes and one visit of the stingless bee did 4.7% on average and that 11 visits of the honey bee or 30 visits of the stingless bee are required per flower to attain normal berry (fertilization rate, 87%). In this study, the rate of deformed berries in the stingless bee area (73%) was lower than that of the control area (90%), but higher than that of the honey bee area (51%). From our numerical model, we conclude the stingless bee could pollinate strawberry as well as the honey bee if we introduced 1.8 times of bees used in this experiment.     

Ergonomics in stingless bees: changes in intranidal behavior after partial removal of storage pots and honey inMelipona favosa (Hym. Apidae,Meliponinae)

Summary The ergonomics of task allocation in stingless bees was examined in two laboratory colonies ofMelipona favosa containing individually marked workers. Performance of intranidal behavior patterns, brood cell production and the processing and storage of nectar, were studied during a control and a wax-deprived period. Experimental wax deprivation consisted of regular controlled removal of storage pots and their contents. Stored carbohydrate concentration and storage pot mass declined during the wax-deprived period. Behavior was measured by sampling for a complete ethogram at seven intranidal areas.In comparison withApis mellifera, M. favosa appeared to be more sensitive to stress, with a distinct reallocation of effort between tasks. The significant increase under stress of brood production and brood-rearing behavior patterns observed was previously also found inApis. Self-oriented behavior patterns declined under stressed circumstances.Involucrum construction declined in wax-deprivedMelipona colonies. Relatively low rates of walking behavior in general inMelipona suggest a low mean free distance between tasks. These results are of particular interest in relation to the basically different nest structure of stingless bees, e.g. very distinct areas for brood production and the processing and storage of food. This architecture of stingless bee nests appeared to influence strongly their specific responses to wax deprivation.     

The influence of nest site selection on the population dynamics of Africanized honey bees in an urban landscape

Urban landscapes provide habitat for many species, including domesticated and feral honey bees, Apis mellifera L. (Hymenoptera: Apidae). With recent losses of managed honey bee colonies, there is increasing interest in feral honey bee colonies and their potential contribution to pollination services in agricultural, natural, and urban settings. However, in some regions the feral honey bee population consists primarily of Africanized honey bees. Africanized honey bees (AHB) are hybrids between European honey bees and the African honey bee, Apis mellifera scutellataLepeletier, and have generated economic, ecological, and human health concerns because of their aggressive behavior. In this study, we used two long‐term datasets (7–10 years) detailing the spatial and temporal distribution of AHB colonies in Tucson, AZ, USA, where feral colonies occupy a variety of cavities including water meter boxes. A stage‐structured matrix model was used to elucidate the implications of nest site selection and the effects of colony terminations on the structure and dynamics of the AHB population. Our results suggest that Tucson's AHB population is driven by a relatively small number of ‘source’ colonies that escape termination (ca. 0.165 colonies per km² or 125 colonies in total), although immigrating swarms and absconding colonies from the surrounding area may have also contributed to the stability of the Tucson AHB population. Furthermore, the structure of the population has likely been impacted by the number and spatial distribution of water meter boxes across the city. The study provides an example of how urban wildlife populations are driven by interactions among landscape structure, human management, and behavioral traits conferred by an invasive genotype.     

Global stingless bee phylogeny supports ancient divergence,vicariance, and long distance dispersal

Stingless bees (Meliponini) are one of only two highly eusocial bees, the other being the well studied honey bee (Apini). Unlike Apini, with only 11 species in the single genus Apis, stingless bees are a large and diverse taxon comprising some 60 genera, many of which are poorly known. This is the first attempt to infer a phylogeny of the group that includes the world fauna and extensive molecular data. Understanding the evolutionary relationships of these bees would provide a basis for behavioural studies within an evolutionary framework, illuminating the origins of complex social behaviour, such as the employment of dance and sound to communicate the location of food or shelter. In addition to a global phylogeny, we also provide estimates of divergence times and ancestral biogeograhic distributions of the major groups. Bayesian and maximum likelihood analyses strongly support a principal division of Meliponini into Old and New World groups, with the Afrotropical+Indo‐Malay/Australian clades comprising the sister group to the large Neotropical clade. The meliponine crown clade is inferred to be of late Gondwanan origin (approximately 80 Mya), undergoing radiations in the Afrotropical and Indo‐Malayan/Australasian regions, approximately 50–60 Mya. In the New World, major diversifications occurred approximately 30–40 Mya. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 99 , 206–232.     

A molecular phylogeny of the genus Apis suggests that the Giant Honey Bee of the Philippines,A. breviligula Maa,and the Plains Honey Bee of southern India,A. indica Fabricius,are valid species

Two new taxa have been added to the existing molecular phylogenies of the genus Apis. The new phylogeny supports the accepted phylogenetic relationships of {dwarf honey bees [giant honey bees (cavity‐nesting honey bees)]}. Based on Bayesian and maximum parsimony trees, our analysis supports recognition of Apis indica, the Plains Honey Bee of south India, as a separate species from A. cerana. Our analysis also supports recognition of the Giant Philippines Honey Bee, A. breviligula, as a separate species from A. dorsata.     

Resource Partitioning between Highly Eusocial Bees and Possible Impact of the Introduced Africanized Honey Bee on Native Stingless Bees in the Brazilian Atlantic Rainforest

The highly eusocial bee community of the neotropical Atlantic Rainforest was studied at Boracéia Biological Station in the state of São Paulo, Brazil. In this reserve, 17 species of stingless bees and the introduced Africanized honey bee were found, the latter being the most abundant flower visitor. Of all flowering plants, Asteraceae and Myrtaceae were particularly important as resources for bees. Trophic niche overlap between the various species of stingless bees is evident, and it was generally larger within the tribes Meliponini and Trigonini than between members of different tribes. Nevertheless, in the stingless bee community the competitive pressure is rather uniformly spread. The trophic niche of the Africanized honey bee can be positioned between those of Meliponini and Trigonini. Today this introduced species represents the main competitor in this bee community. However, its impact on native stingless bee populations is apparently buffered by mass-flowering trees which are the most important food plants of the indigenous highly eusocial bees.     

Key factors influencing forager distribution across macadamia orchards differ among species of managed bees

To achieve maximised and sustainable crop productivity, it is critical that we develop crop-specific strategies for managing pollination. Honey bees (Apis mellifera) and stingless bees (Tetragonula carbonaria) are considered effective pollinators of macadamia (Macadamia integrifolia). The introduction of managed honey bee or stingless bee hives into orchards is likely to boost the numbers of these insects visiting flowers; however, there is a lack of published information and consensus regarding their management for pollination. Here, we identify factors that affect the distribution of both honey bees and stingless bees across cultivated macadamia, and establish whether increased flower visitation leads to higher nut set. A gradient of bee visitation rates was created by placing colonies on the ends of a four-hectare block, and mixed-effect models were applied to assess forager abundance and nut set with respect to distance from hive, time of day, cultivar, and floral display size. Distance from colony had a strong effect on stingless bee numbers, with >96% of individuals recorded within 100 metres of colonies, whereas the distribution of honey bees was more closely related to daily floral display: trees with greater numbers of flowers attracted more honey bees. Simplified surveys conducted in a further 17 macadamia blocks confirm that these are broadly occurring distribution patterns. Bee abundance alone did not significantly predict nut production; however, an indirect effect of bee visits to flowers is inferred, as nut production increased with size of floral display. To encourage a more even distribution of bees and uniform pollination, we recommend placement of stingless bee hives to maximise their distribution through a block (e.g. at 100-m intervals) and management practices that promote even distributions of flowers across trees.     

Predation of Lapwing Vanellus vanellus nests on lowland wet grassland in England and Wales: effects of nest density, habitat and predator abundance

There is concern that predation of Lapwing Vanellus vanellus nests may create additional pressure on declining populations of this species in Europe. At seven sites in England and Wales, daily nest predation rates on 1,390 nests were related to variables using Generalised Linear Mixed Models. The strongest predictor was Lapwing nest density (number of nests within 100 m): predation rates declined as nest density increased. Since nocturnal species, probably mammals, have been identified as the major predators of Lapwing nests at these sites, these results suggest that Lapwings are able to deter mammalian predators or may settle to nest at high densities in areas with low predation pressure. At the site level, there was no relationship between Lapwing nesting density and fox density, and a positive relationship with Carrion Crow Corvus corone nesting density. There was a weaker effect of distance to field boundary: nests closer to boundaries were more likely to be predated. Weak interactive effects between crow density and both nest visibility and distance to vantage point were identified in models using a reduced subset of nests. These were counter-intuitive, did not persist in the larger data set, and do not have obvious explanations. If Lapwings nesting at high density are able to deter predators, there are implications for land management. Smaller areas could be managed within potential breeding habitat to encourage Lapwings to nest in dense colonies. Selection of larger fields for such management, where nests could be located far from the field boundary should improve the value of such measures.     

csd alleles in the red dwarf honey bee (Apis florea,Hymenoptera: Apidae) show exceptionally high nucleotide diversity

Abstract The single locus complementary sex determination (sl‐csd) gene is the primary gene determining the gender of honey bees (Apis spp.). While the csd gene has been well studied in the Western honey bee (Apis mellifera), and comparable data exist in both the Eastern honey bee (Apis cerana) and the giant honey bee (Apis dorsata), no studies have been conducted in the red dwarf honey bee, Apis florea. In this study we cloned the genomic region 3 of the A. florea csd gene from 60 workers, and identified 12 csd alleles. Analysis showed that similar to A. mellifera, region 3 of the csd gene contains a RS domain at the N terminal, a proline‐rich domain at the C terminal, and a hypervariable region in the middle. However, the A. florea csd gene possessed a much higher level of nucleotide diversity, compared to A. mellifera, A. cerana and Apis dorsata. We also show that similar to the other three Apis species, in A. florea, nonsynonymous mutations in the csd gene are selectively favored in young alleles.     

Factors influencing the nesting success of Lapwings Vanellus vanellus and behaviour of Red Fox Vulpes vulpes in Lapwing nesting sites

Capsule Lapwing nest predation was negatively correlated to nest density, while Lapwing alarm duration in response to foxes was positively correlated with the number of Lapwing broods present.

Aims To identify factors affecting Lapwing nest predation and Red Fox search effort.

Methods Lapwing nest success was monitored at four sites in 1996, seven sites in 1997 and six sites in 1998. In 1997 we mapped the position of all Lapwing nests in order to determine distances between nests, and the proximity of linear features and potential avian predator perches to each nest. From April to June 1998 we carried out 199 hours of nocturnal observations at six Lapwing nesting sites using night vision equipment.

Results The risk of nest predation was significantly higher for more isolated nests. Nocturnal observations showed that of all the nocturnal predators, foxes were the most active at Lapwing nesting sites. However, fox search effort in Lapwing colonies was relatively low, averaging 57 s/ha per visit. Foxes spent significantly longer foraging near breeding Lapwings (measured as duration of alarm calls) when more broods were present. Fox search effort (s/ha per hour of observation) tended to be greater in areas of high waterbird density.

Conclusion The lack of positive density-dependent nest predation, the relatively low search effort of foxes near Lapwing nesting sites and the high nest success sometimes achieved in areas with foxes all suggest that Lapwing nest predation by foxes is ‘incidental’. Lapwing chicks are probably more vulnerable to predation by foxes than clutches.     

Fitness consequences of ecological constraints and implications for the evolution of sociality in an incipiently social bee

Ecological constraints such as resource limitation, unfavourable weather conditions, and parasite pressure have long been considered some of the most important selective pressures for the evolution of sociality. In the present study, we assess the fitness consequences of these three ecological factors on reproductive success of solitary nests and social colonies in the socially polymorphic small carpenter bee, Ceratina australensis, based on 982 nests collected over four reproductive periods. Nest site limitation was predicted to decrease opportunities for independent nest initiation and increase the frequency of social nesting. Nest sites were not limiting in this species and the frequency of social nesting was consistent across the four brood‐rearing periods studied. Unfavourable weather was predicted to lower the frequency of female dispersal from their natal nests and to limit the brood‐rearing season; this would increase the frequency and fitness of social colonies. Daily temperature and precipitation accumulation varied between seasons but were not correlated with reproductive success in this bee. Increased parasite pressure is predicted to increase the frequency and fitness of social colonies because solitary bees must leave the nest unattended during foraging bouts and are less able to defend the nest against parasites. Severe parasitism by a chalcid wasp (Eurytoma sp.) resulted in low reproductive success and total nest failure in solitary nests. Social colonies had higher reproductive success and were never extirpated by parasites. The high frequency of solitary nests suggests that this is the optimal strategy. However, social colonies have a selective advantage over solitary nesting females during periods of extreme parasite pressure, and we suggest that social nesting represents a form of bet‐hedging against unpredictable fluctuations in parasite number. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 103 , 57–67.