Large Carpenter Bees Research Articles

The earliest large carpenter bee (Xylocopa) and its adhering pollen (Araliaceae, Theaceae)

AbstractThe association of pollinators with their host plants is a critical element of ecosystem functioning and one that is usually determined indirectly in the fossil record from specific morphological traits of flowers or putative pollinating animals. The exceptionally fine preservation at Messel, Germany, offers an excellent source of data on pollen from fossil flowers as well as preserved adhering to insects as direct evidence of their association with specific floral lineages. Here, we report on pollen recovered from the body and legs of a large carpenter bee (Apidae: Xylocopinae: Xylocopini) from the Eocene of Messel. The fossil is the earliest occurrence of the tribe Xylocopini and represents an extinct subgenus and species, described as Xylocopa (Apocolyx) primigenia subgen. et sp. nov. Two eudicot pollen types were recovered from the bee, one of the family Theaceae (Asterids: Ericales) and another of Araliaceae (Euasterids: Apiales). The pollen grains are compared with various extinct and extant pollen types, and data on floral visitors to modern theaceous and araliaceous flowers are explored in relation to understanding the association of the fossil carpenter with these floral types in the paratropical Eocene biota of Messel.

A shift between bee and wasp pollinators explains floral divergence in the Duvernoia clade of Justicia (Acanthaceae)

Abstract Floral divergence among sister taxa can arise from pollinator shifts and play a role in speciation. We investigate a potential case of pollinator-driven divergence in the Duvernoia clade of Justicia (Acanthaceae), which includes two species with markedly divergent floral morphology. Pollinator observations and pollen load analyses showed that Justicia aconitiflora is pollinated by vespid wasps, while its sister taxon Justicia adhatodoides is confirmed to be pollinated exclusively by large carpenter bees. Reciprocal nectar-feeding experiments show that wasps and bees are not deterred by the taste of nectar of non-preferred species. Floral morphology matches body and tongue morphology of these two insect groups, and this phenotypic matching mediates pollen transfer and physical access to nectar. Controlled pollination experiments showed that both species are self-compatible, yet dependent on pollinator visits for fruit-set. Historical reconstruction of pollination system evolution in Justicia indicates that the direction of the shift in the Duvernoia clade was from bee to wasp pollinators. This study provides a compelling example of a transition between bee and wasp pollination, and highlights the effects of floral architecture on specialization in plant pollination systems.

A scientific note on the differential handling behaviour of two large carpenter bees on an inverted keel flower

A scientific note on the differential handling behaviour of two large carpenter bees on an inverted keel flower

Individual Variation in Male Pheromone Production in Xylocopa sonorina Correlates with size and Gland Color.

Sex pheromones are species-specific chemical signals that facilitate the location, identification, and selection of mating partners. These pheromones can vary between individuals, and act as signals of mate quality. Here, we investigate the variation of male pheromones in the mesosomal glands of the large carpenter bee Xylocopa sonorina, within a Northern California population. We tested the hypothesis that morphological traits are correlated with the observed variation in chemical blend composition of these bees. We also conducted behavioral assays to test whether these male pheromones act as long-range attractants to conspecifics. We found that larger males with darker mesosomal glands have a higher pheromone amount in their glands. Our analysis also suggests that this pheromone blend functions as a long-range attractant to both males and females. We show that both male body size and sexual maturation are important factors influencing pheromone abundance, and that this pheromone blend acts as a long-range attractant. We hypothesize that this recorded variation in male pheromone could be important for female choice.

Effects of arsenic and selenium pollution on wild bee communities in the agricultural landscapes

Wild bees play crucial roles in pollinating numerous crops and fruits worldwide. However, these essential insect pollinators are threatened with decline due to a variety of stressors. Among stressors, relatively little work has been done on metalloid pollution. Laboratory experiments have shown that arsenic (As) and selenium (Se) can negatively impact on bees, it is unknown if these effects translate in real-world environments. To address this knowledge gap, wild bee communities were sampled from 18 smallholder farmlands in Kaihua County in Quzhou, Southeast China and As and Se concentrations in three bee species were measured (Xylocopa tranquebarorum, Eucera floralia, and Apis cerana). Analyses revealed that the large carpenter bee, X. tranquebarorum, exhibited significantly lower As and Se concentrations than the other two wild bee species. No significant correlations were found between As and Se concentrations in all three wild bee species. Interestingly, the proportion of semi-natural habitat was found to be significantly related to reduced Se concentration in wild bee bodies, though no such effect was observed for As. As pollution negatively impacted bee diversity but not abundance, whereas Se significantly impacted neither bee diversity nor abundance. Furthermore, both As and Se pollution had no significant effect on the abundance of small-bodied wild bees. Given the essential role of wild bees for pollination services, monitoring of As and Se pollution in wild bee bodies and their food resources (pollen and nectar) is recommended across agricultural and other potentially impacted systems.

The First Record of Calvolia summersi (Mostafa, 1970) (Acari: Winterschmidtiidae) from the Oriental Region and a new record of host association with Xylocopa (Ctenoxylocopa) fenestrata (Fabricius, 1798) with a review on Xylocopa-mite associations in India

Mites have long been associated with bees, often showing a close relationship with particular taxa, probably due to a co-evolutionary process. The present study is the first confirmation on the occurrence of the mite species Calvolia summersi (Mostafa, 1970) in India and its association with Xylocopa fenestrata (Fabricius, 1798), a large carpenter bee species. The mite species was previously reported from Brazil in association with Zethus, a neotropical potter wasp genus. C. summersi is isolated and studied from different populations of X. fenestrata in Sagar Islands, West Bengal, the biggest island of mangrove Sundarban deltaic complex. A literature-based review of the Xylocopa-mite associations from India is provided herewith to understand the diversity and pattern of mite species on Xylocopa host selection in the country. Instigating a baseline study of Xylocopa-mite association is recommended to demark the status of dynamism for better conservation and protection.

New species of genus Dinogamasus Kramer (Mesostigmata, Laelapidae) associated with large carpenter bees (Hymenoptera: Apidae) in Egypt, with new concepts of the genus

The Laelapid family of cosmopolitan mites includes both free-living predators and associated species to arthropods, mammals, or birds. A new species of laelapid mite, Dinogamasus pubescensae n. sp. Abo-Shnaf and Kamel associated with Xylocopa pubescens Spinola (Hymenoptera: Apidae), is described and illustrated. This is a third report of the genus Dinogamasus from Egypt. The new species can be distinguished from its congeners by the combination of the following characters: dorsal cheliceral seta present; hypertrichous idiosoma and opisthogaster; sternum without accessory setae, st2 longest, st4 present, endopodal and metapodal plates present, genital shield shorter than anal shield, anal shield rectangular. The genus diagnoses are discussed in terms of new notions. Modification of Lundqvist’s key (1999) is made to facilitate identification of D. pubescensae n. sp. Abo-Shnaf and Kamel from other species.

Andromonoecy functional through heterostyly and large carpenter bees as principal pollinators in Solanum carolinense L. (Solanaceae)

Solanum carolinense is a perennial shrubby weed. In this species, andromonoecy is functional through heterostyly represented by the production of long, semi-long, medium, & short-styled flower types and another flower type lacking style & stigma completely. All plants produce long-styled flowers while all individuals do not produce other flower types. The long- and semi-long-styled flowers are functionally co-sexual and produce fruit while the other flower types are functionally female-sterile and do not produce fruit. The position of style in long- and semi-long-styled flowers facilitates the act of pollination by pollinator bees. Xylocopa bees are large-bodied specialist bees which collect pollen from poricidal anthers efficiently in this plant by displaying buzzing behaviour and are treated as principal pollinators. The other bees are small-bodied and do not display buzzing behaviour to release pollen from poricidal anthers but they simply collect residual pollen available around the rim of the apical pore of the anthers, and hence they act as supplementary pollinators only. In this plant, the style length has a positive relationship with pollen deposition and a negative relationship with pollen removal in flowers visited by large carpenter bees of Xylocopa genus and hence, pollinator-specific interactions with flower morphology are important in the maintenance and perfect evolution of andromonoecy in this plant species. Florivory by Mylabris pustulata could vary with the flower production rate in S. carolinense and could favor higher floral-sex ratios biased in favour of higher proportion of female-sterile flowers.

Notes on the large carpenter bees, genus Xylocopa Linnaeus, 1758 (Hymenoptera: Apidae) from Sagar Island, India

Notes on the large carpenter bees, genus Xylocopa Linnaeus, 1758 (Hymenoptera: Apidae) from Sagar Island, India

Scientific note: the nesting behaviour of two large carpenter bees of the genus Xylocopa (Hymenoptera: Apidae) from Vietnam

Scientific note: the nesting behaviour of two large carpenter bees of the genus Xylocopa (Hymenoptera: Apidae) from Vietnam

Descriptions of new gynandromorphs of Xylocopa augusti Lepeletier (Hymenoptera: Apidae: Xylocopini) from Argentina

Gynandromorphs are individuals that display both male and female features throughout the body and are rarely found in nature. We document and describe two new gynandromorphs of the large carpenter bee Xylocopa (Neoxylocopa) augusti reared from a trap-nest in La Plata, Buenos Aires, Argentina. In addition, based on a literature review, we assessed the frequency of the different types of gynandromorphs, and the body part affected, among large carpenter bees. Both gynandromorphs were assigned to the mixed category, the most common category reported in the literature (22 of 25 specimens). The remaining three specimens exhibit a bilateral pattern in all tagmata. The presence of both sexes' secondary sexual characteristics occurred more frequently on the mesosoma than on the head or metasoma. Trap nests used in bee hotels promote the conservation and study of wild bees and might facilitate the discovery of rare cases of gynandromorphs that would remain unknown otherwise under normal nesting conditions in the wild.

First record of the gregarious parasitoid Leucospis leucotelus Walker (Leucospidae) attacking nests of Xylocopa (Neoxylocopa) frontalis (Olivier) (Apidae)

Notes on three nests of the large carpenter bee Xylocopa (Neoxylocopa) frontalis (Olivier) (Apidae) attacked by the parasitoid Leucospis leucotelus Walker (Leucospidae) are presented. We observed that host brood cells contained from four to 12 parasitoids (adults or immature) which allowed us to identify this Leucospis species as a gregarious parasitoid. This was the first record of a gregarious Leucospis species attacking X. frontalis nests.

Thermoregulation in the large carpenter bee Xylocopa frontalis in the face of climate change in the Neotropics

There is evidence that climate change may worsen the ecological conditions needed by many pollinator species for their survival; however, little is known about how the rise in ambient temperature might affect the survival of large bee species in tropical regions of the planet. This study investigated the thermoregulation mechanisms of the large carpenter bee Xylocopa frontalis when nesting spontaneously in nests designed to allow direct measurement of the bees’ temperature while carrying out different activities. It was seen that the species divides its activities throughout the day according to the amount of body heat generated and the ambient temperature, performing activities that generate more body heat at cooler times of the day. The bees also use strategies of thermoregulation, such as heat loss by air convection, evaporative cooling by nectar dehydration, and not foraging during the hottest times of the day to avoid overheating. The study shows that X. frontalis is well adjusted to the ecological conditions of the areas in which it lives but suggests that future rises in the ambient temperature could pose a serious threat to the survival and pollination services provided by this bee and other similar tropical species.

First Records of Xylocopa virginica (Linnaeus) (Hymenoptera: Apidae) in Montana and Idaho

A species of large carpenter bee, Xylocopa virginica virginica (Linnaeus, 1771), is reported from Montana and Idaho, USA for the first time. This new Montana distribution record adds to a growing list of bee species found in the state and contributes to an ongoing inventory of the bees of Montana. The Montana collection likely does not represent an established population but a transient accidental introduction resulting from human transportation since Montana is considerably geographically separated from the published distribution of this species and no additional adults have been found. The Idaho collections may represent an established local population as there are several specimens and online records in or near Boise on multiple dates and years. An online record of a specimen of X. californica arizonensis Cresson, 1879 from Montana proved to be erroneous. The distribution of X. virginica is reviewed and the economic, social, and ecological implications of the occurrence or establishment of this species in Montana and Idaho are discussed.

Buzz pollination

Pritchard and Vallejo-Marín introduce the process and evolution of buzz pollination.

Timing of male territorial flight and foraging of the large carpenter bee Xylocopa appendiculata related to serotonin in the brain.

To determine how males of the large carpenter bee, Xylocopa appendiculata, maximize access to females while minimizing energy cost and acquiring energy for territorial flights, we investigated the times of territorial flights by males and foraging by males and females. Males were present continuously in territories from 8:00 to 12:00. They approached, chased, and excluded conspecific males from their territories. In the laboratory, males showed higher locomotor and flight activities in the morning and lower activities in the afternoon. Both males and females visited flowers from 8:00 to 16:00, but the most frequent visits were earlier in females (10:00-12:00) than in males (12:00-13:00). Relative body weights in territorial males often increased. These results indicate that the males time their territorial flights to maximize contact with females and obtain nectar as fuel between and after the territorial flights. The time-related territorial flight in males might be based on a time-keeping system in the brain. Brain levels of serotonin and its precursor tryptophan were significantly higher in males collected at 16:00 than at 11:00, suggesting a relation between time-related territorial flight and serotonin synthesis in the brain.

Xylocopa sonorina Smith, 1874 from Vancouver, British Columbia, Canada (Hymenoptera: Apidae, Xylocopinae) with comments on its taxonomy.

BackgroundOnly one species of large carpenter bee, Xylocopa virginica (Linnaeus, 1771), has been recorded from Canada, albeit restricted to southern Ontario and Quebec. However, a single female specimen identified by Hurd in 1954 as X. varipuncta Patton, 1879 from British Columbia is in the C.A. Triplehorn Insect Collection at The Ohio State University (OSUC), suggesting that this species was accidentally introduced into coastal western Canada. As wood-nesters, many large carpenter bees are likely capable of expanding their range great distances by natural and unnatural transport methods while nesting inside suitable substrates, the presumed mode of transport into western Canada, and likely elsewhere. The ease at which the nests are transported has likely contributed to the nomenclatural and distributional ambiguity surrounding this species due to morphological similarities of specimens from North America, Hawaii, and several South Pacific islands.New informationBy comparing DNA barcodes of specimens from the western United States to specimens from Hawaii, we confirm the early opinion of P.H. Timberlake (Timberlake 1922) that specimens long established on the Hawaiian Islands are the same X. varipuncta from continental North America. Furthermore, these DNA barcode sequences also match those of specimens identified as X. sonorina Smith, 1874 from the French Polynesian and Samoan Islands, thus fully supporting the opinion of Groom et al. (2017) that all are likely conspecific. As X. sonorina, a species described from and likely introduced to Hawaii is the oldest name available, X. varipuncta is here placed into synonymy. Additional research will be needed to trace the timing and pathway of introduction and establishment of X. sonorina; it is presumed that the species is native to the southwestern United States but has been established in Hawaii since the mid-1800s. It is also established in French Polynesia, the Samoan Islands, and likely other south Pacific islands, with additional records of occurrence from Java, New Zealand, and now Canada.

Thermal tolerance varies with dim‐light foraging and elevation in large carpenter bees (Hymenoptera: Apidae: Xylocopini)

1. Thermal tolerance has a strong predictive power for understanding the ecology and distribution of organisms, as well as their responses to changes in land use and global warming. However, relatively few studies have assessed thermal tolerances for bees.2. The present study aimed to determine whether the critical thermal maximum (CTmax) of carpenter bees (Apidae: genus Xylocopa Latreille) varies with different patterns of foraging activity and elevation. In addition, the influence of body size, body water content and relative age was examined with respect to their CTmax and differences in thoracic temperature (Tth) among species were evaluated.3. The CTmax of one crepuscular (Xylocopa olivieri) and two diurnal species (Xylocopa violacea and Xylocopa iris) of carpenter bees was assessed at sea level on the Greek island of Lesvos. To detect variation as a result of elevation, the CTmax of a population of X. violacea at 625 m.a.s l. was assessed and compared with that from sea level.4. Xylocopa olivieri displayed a similar CTmax to that of X. violacea but lower than that of X. iris. Body size, body water content, and relative age did not affect CTmax. In X. violacea, CTmax decreased with elevation and all three species have high Tth independent of ambient temperatures.5. The results of the present study are consistent with variations in CTmax predicted by broad spatial and temporal patterns reported for other insects, including honey and bumble bees. The implications of the results are discussed aiming to understand the differences in the foraging pattern of these bees.

Large carpenter bees as key pollinators of gliricidia sepium

Large carpenter bees as key pollinators of gliricidia sepium

Foraging strategies and physiological adaptations in large carpenter bees.

Large carpenter bees are charismatic and ubiquitous flower visitors in the tropics and sub-tropics. Unlike honeybees and bumblebees that have been popular subjects of extensive studies on their neuroethology, behaviour and ecology, carpenter bees have received little attention. This review integrates what is known about their foraging behaviour as well as sensory, physiological and cognitive adaptations and is motivated by their versatility as flower visitors and pollinators. This is evident from their extremely generalist foraging and adeptness at handling diverse flower types as legitimate pollinators and as illegitimate nectar robbers. They purportedly use traplining to forage between isolated patches and are long-distance flyers over several kilometres suggesting well-developed spatial learning, route memory and navigational capabilities. They have a broad range of temperature tolerance and thermoregulatory capabilities which are likely employed in their forays into crepuscular and nocturnal time periods. Such temporal extensions into dim-light periods invoke a suite of visual adaptations in their apposition optics. Thus, we propose that carpenter bees are an excellent though understudied group for exploring the complex nature of plant-pollinator mutualisms from ecological and mechanistic perspectives.