Apidae Research Articles

Short-term heat exposure at sublethal temperatures reduces sperm quality in males of a solitary bee species, Osmia cornifrons

Increased temperature variability and extreme weather events associated with climate change can be detrimental to bees and lead to their population declines. While there is some research on the effects of heatwaves on insect biology and reproduction, impacts on male insect reproduction are not well described. Solitary bees may be more exposed to temperature variation than social bees, since there is no mitigation by group thermoregulation. Here, we evaluated the effects of sublethal heat exposure (at 30 °C and 38 °C) on reproductive fitness of adult males of a solitary bee species, Osmia cornifrons. After 4 h of heat exposure, bees were maintained at 24 °C for 48 h in laboratory cages to reach sexual maturity and later analyzed for sperm abundance (quantity) and proportion of viable sperm (quality). Bees that were reared and maintained at 24 °C served as controls. Despite rehabilitation after heat exposure, both sperm quantity and quality of male O. cornifrons bees were significantly reduced in heat-treated groups compared to controls. These results demonstrate that the exposure to elevated non-lethal temperatures, even for short periods and allowing time for recovery, may negatively affect the reproductive capacity of male solitary bees. Our findings reveal a possible mechanistic explanation for wild bee population declines. Given the importance of solitary bee species (such as O. cornifrons) in natural and agricultural landscapes, our study provides valuable insights into the potential consequences of climate change on these insect populations and the ecosystems they inhabit.

Bees remain heat tolerant after acute exposure to desiccation and starvation.

Organisms may simultaneously face thermal, desiccation and nutritional stress under climate change. Understanding the effects arising from the interactions among these stressors is relevant for predicting organisms' responses to climate change and for developing effective conservation strategies. Using both dynamic and static protocols, we assessed for the first time how sublethal desiccation exposure (at 16.7%, 50.0% and 83.3% of LD50) impacts the heat tolerance of foragers from two social bee species found on the Greek island of Lesbos: the managed European honey bee, Apis mellifera, and the wild, ground-nesting sweat bee Lasioglossum malachurum. In addition, we explored how a short-term starvation period (24 h), followed by a moderate sublethal desiccation exposure (50% of LD50), influences honey bee heat tolerance. We found that neither the critical thermal maximum (CTmax) nor the time to heat stupor was significantly impacted by sublethal desiccation exposure in either species. Similarly, starvation followed by moderate sublethal desiccation did not affect the average CTmax estimate, but it did increase its variance. Our results suggest that sublethal exposure to these environmental stressors may not always lead to significant changes in bees' heat tolerance or increase vulnerability to rapid temperature changes during extreme weather events, such as heat waves. However, the increase in CTmax variance suggests greater variability in individual responses to temperature stress under climate change, which may impact colony-level performance. The ability to withstand desiccation may be impacted by unmeasured hypoxic conditions and the overall effect of these stressors on solitary species remains to be assessed.

The potential of weeds in arable fields to support pollinator assemblages

AbstractTo what extent are weeds on arable land useful to pollinators in an arable‐dominated landscape? We sampled the weed flora in fields under conventional or organic farming in SE Sweden. More specifically, we noted the frequency of flowering among weeds that scored high on a pollinator index, henceforth ‘pollinator‐friendly weeds’. Furthermore, we sampled pollinating insects within cereal crops using transect walks and colour pan traps. As expected, weeds were ubiquitous and occurred in most sampling plots (0.25 m2). In the pan traps, more than 100 species of pollinators were caught, including 26 Syrphidae, 19 social bees, 37 solitary bees and 22 other Hymenoptera. In the transects walks, the probability of encountering bees increased with flowering of pollinator‐friendly weeds, and there was a similar but weaker pattern among hoverflies. Organically grown fields differed from conventional ones by having more pollinator‐friendly weeds, more flowering of such weeds, and more bees. There was also a tendency for hoverflies and other Hymenoptera to be more abundant in organic fields. Three conclusions emerged. First, pollinator‐friendly weeds made up one third to almost half of the weed occurrences recorded. Second, substantial numbers of pollinators searched for flowers within arable fields, and some increased with the abundance of flowering of pollinator‐friendly weeds. Third, flowering pollinator‐friendly weeds and some pollinators were more abundant in organic fields than in conventional ones. Overall, we showed that weeds on arable land are a potential and sought after resource among pollinators, and that even conventionally grown crops should be considered a potential habitat for bees.

A Review on the Sublethal Effects of Pure and Formulated Glyphosate on Bees, with a Focus on Social Bee Species

Glyphosate, one of the most widely used herbicides globally, has been extensively applied in agriculture due to its efficacy in weed control. However, recent studies have raised concerns about its sublethal effects on non-target organisms, particularly social bee species such as honeybees (Apis mellifera), bumblebees (Bombus spp.), and stingless bees (e.g., Melipona, Trigona). While glyphosate's primary mechanism targets the shikimate pathway, which is absent in animals, emerging evidence suggests it can indirectly impact bees by altering their gut microbiota, immune responses, and behavior. Research shows that even at sublethal doses, glyphosate can impair navigation, learning, and foraging efficiency, leading to reduced colony growth and survival rates. Field and laboratory studies indicate that the impact is exacerbated when bees are exposed to formulated products containing surfactants, which increase glyphosate’s toxicity. Furthermore, the disruption of social behaviors within colonies, such as communication through the waggle dance in honeybees, has profound implications for hive health and productivity. Despite growing evidence, there remain significant gaps in our understanding of glyphosate’s long-term and chronic effects, especially across diverse ecosystems and bee species. Current research is limited by a lack of longitudinal field studies that assess the cumulative impact of low-dose exposure over multiple generations. Most studies have focused on honeybees, with less attention given to wild and native bee populations, which may respond differently to glyphosate. To address these challenges, future research must prioritize mechanistic studies, explore eco-friendly alternatives to glyphosate, and implement integrated pest management strategies to reduce agrochemical dependence. Collaboration among scientists, policymakers, and stakeholders is critical to developing evidence-based regulations that protect pollinator health. Given the essential role bees play in global food security through pollination, protecting these vital species from the sublethal effects of glyphosate is not only an ecological imperative but also a socioeconomic necessity. Immediate actions in research, policy reform, and sustainable agricultural practices are needed to mitigate the risks posed by glyphosate and safeguard the future of pollinators.

Pollen Composition from Coexisting Melipona scutellaris and Tetragonisca angustula Nests in a Semi-urban Meliponary Setting.

The Meliponini tribe is the most diverse group of social bees, thriving across tropical regions. Breeding stingless bees (meliponiculture) holds significant ecological and economic value. In meliponaries, multiple species often share small foraging areas, a scenario less common in natural environments. Due to deforestation, stingless bees face a diminishing availability of natural nesting sites, which are often found in hollow tree trunks. Consequently, meliponaries serve as a crucial nesting resource. In this study, we examined whether Melipona scutellaris and Tetragonisca angustula share pollen resources when reared closely together in high-density nest environment at the RCCO Meliponary in Aldeia, Camaragibe, and Pernambuco, which could potentially lead to competition. Our findings indicate that these bee species utilize different pollen sources, being Araceae type 1, Mimosoideae type 1, Asteraceae type 1, and Myrtaceae type 1 the most important for differentiating between groups. Their daily activity periods outside the nest differ, leading to varying responses to changes in temperature and humidity. The results suggest that competition for pollen resources may not be a significant issue between the two bee species in such situations.

Research Into the Bee Population (Hymenoptera: Apoidea: Apiformes) in the Grassland Habitats of Cisowsko-Orłowiński Landscape Park as Reinforcement for Educational Awareness of a Society

Abstract The aim of the research, conducted from April to October 2018–2019, was to characterize the bee populations (Apiformes) in phytosociological diverse grassland areas of Cisowsko-Orłowiński Landscape Park (C-OLP), located in Małopolska Upland. Such a characteristic was a crucial condition to perform further steps aimed at preventing threats to these insects. The transect method and Moericke traps were applied to sample bees. 126 bee species were recorded in four research areas with Apidae family representatives being dominant (44.9%). The transect method proved more efficient than the traps since it provided 123 insect species. Species diversity H’ and equivalence J’ indices reached the highest parameters in fields (FI) and meadows (ME) and the lowest in xerothermic grasslands (XG). Spearman’s rank correlation coefficient demonstrated positive and strong correlation of variables H’ and J’ and S. It applied to both the transect method and the traps, the latter demonstrating bigger correlation.

Genomic architecture in social insects is more strongly associated with phylogeny than social behavior

Abstract The evolution of sociality in insects has been predicted to reduce effective population sizes, in turn leading to changes in genome architecture, including higher recombination rates, larger genomes, increased GC-biased gene conversion (gBGC), and greater intragenomic variation in GC content to maintain castes through differential methylation. As the number of sequenced insect genomes continues to grow, it remains an open question which, if any, of these genomic features are consistent across social insect genomes. A major challenge to determining such commonalities has been the lack of phylogenetically controlled analyses across independent origins of sociality. Of the 15 Hymenoptera species for which recombination rate was available, social species had higher rates of recombination. Next, we conducted a broader analysis of genome architecture by analyzing genome assemblies for 435 species of Hymenoptera and 8 species of Blattodea to test if GC content, genome size, distribution of CpG sites or codon bias repeatedly differed between social and nonsocial species. Overall, there was little support for predictable changes in genome architecture associated with sociality across Hymenoptera, after accounting for phylogenetic relationships. However, we found a significant negative relationship between sociality and GC content within the family Apidae and a significant negative relationship between sociality and genome size within the family Halictidae. In all, these results suggest that unique origins of social behavior may produce unique trends in genomic architecture. Our study highlights the need to examine genome architecture across independent origins of social behavior.

Environmentally acquired gut-associated bacteria are not critical for growth and survival in a solitary bee, Megachile rotundata.

Social bees have been extensively studied for their gut microbial functions, but the significance of the gut microbiota in solitary bees remains less explored. Solitary bee, Megachile rotundata females provision their offspring with pollen from various plant species, harboring a diverse microbial community that colonizes larvae guts. The Apilactobacillus is the most abundant microbe, but evidence concerning the effects of Apilactobacillus and other provision microbes on growth and survival are lacking. We hypothesized that the presence of Apilactobacillus in abundance would enhance larval and prepupal development, weight, and survival, while the absence of intact microbial communities was expected to have a negative impact on bee fitness. We reared larvae on pollen provisions with naturally collected microbial communities (Natural pollen) or devoid of microbial communities (Sterile pollen). We also assessed the impact of introducing Apilactobacillus micheneri by adding it to both types of pollen provisions. Feeding larvae with sterile pollen + A. micheneri led to the highest mortality rate, followed by natural pollen + A. micheneri, and sterile pollen. Larval development was significantly delayed in groups fed with sterile pollen. Interestingly, larval and prepupal weights did not significantly differ across treatments compared to natural pollen-fed larvae. 16S rRNA gene sequencing found a dominance of Sodalis, when A. micheneri was introduced to natural pollen. The presence of Sodalis with abundant A. micheneri suggests potential crosstalk between both, shaping bee nutrition and health. Hence, this study highlights that the reliance on nonhost-specific environmental bacteria may not impact fitness of M. rotundata.IMPORTANCEThis study investigates the impact of environmentally acquired gut microbes of solitary bee fitness with insights into the microbial ecology of bee and their health. While the symbiotic microbiome is well-studied in social bees, the role of environmental acquired microbiota in solitary bees remains unclear. Assessing this relationship in a solitary pollinator, the leaf-cutting bee, Megachile rotundata, we discovered that this bee species does not depend on the diverse environmental bacteria found in pollen for either its larval growth or survival. Surprisingly, high concentrations of the most abundant pollen bacteria, Apilactobacillus micheneri did not consistently benefit bee fitness, but caused larval mortality. Our findings also suggest an interaction between Apilactobacillus and the Sodalis and perhaps their role in bee nutrition. Hence, this study provides significant insights that contribute to understanding the fitness, conservation, and pollination ecology of other solitary bee species in the future.

Weed Role for Pollinator in the Agroecosystem: Plant-Insect Interactions and Agronomic Strategies for Biodiversity Conservation.

The growing interest in safeguarding agroecosystem biodiversity has led to interest in studying ecological interactions among the various organisms present within the agroecosystem. Indeed, mutualisms between weeds and pollinators are of crucial importance as they influence the respective survival dynamics. In this review, the mutualistic role of flower visitors and the possible (often predominant) abiotic alternatives to insect pollination (self- and wind-pollination) are investigated. Mutualistic relations are discussed in terms of reward (pollen and/or nectar) and attractiveness (color, shape, scent, nectar quality and quantity), analyzing whether and to what extent typical weeds are linked to pollinators by rigid (specialization) or flexible (generalization) mutualistic relations. The entomofauna involved is composed mainly of solitary and social bees, bumblebees, Diptera, and Lepidoptera. While some of these pollinators are polylectic, others are oligolectic, depending on the shape of their mouthparts, which can be suited to explore the flower corollas as function of their depths. Consequently, the persistence dynamics of weed species show more successful survival in plants that are basically (occasional insect pollination) or totally (self and/or wind pollination) unspecialized in mutualistic relations. However, even weed species with typical abiotic pollination are at times visited during periods such as late summer, in which plants with more abundant rewards are insufficiently present or completely absent. Many typically insect-pollinated weeds can represent a valid indicator of the ecological sustainability of crop management techniques, as their survival dynamics are closely dependent on the biodiversity of the surrounding entomofauna. In particular, the presence of plant communities of species pollinated above all by butterflies (e.g., several Caryophyllaceae) gives evidence to the ecological compatibility of the previous agronomic management, in the sense that butterflies require certain weed species for oviposition and subsequent larva rearing and, therefore, provide further evidence of plant biodiversity in the environment.

How does climate change impact social bees and bee sociality?

Climatic factors are known to shape the expression of social behaviours. Likewise, variation in social behaviour can dictate climate responses. Understanding interactions between climate and sociality is crucial for forecasting vulnerability and resilience to climate change across animal taxa. These interactions are particularly relevant for taxa like bees that exhibit a broad diversity of social states. An emerging body of literature aims to quantify bee responses to environmental change with respect to variation in key functional traits, including sociality. Additionally, decades of research on environmental drivers of social evolution may prove fruitful for predicting shifts in the costs and benefits of social strategies under climate change. In this review, we explore these findings to ask two interconnected questions: (a) how does sociality mediate vulnerability to climate change, and (b) how might climate change impact social organisation in bees? We highlight traits that intersect with bee sociality that may confer resilience to climate change (e.g. extended activity periods, diet breadth, behavioural thermoregulation) and we generate predictions about the impacts of climate change on the expression and distribution of social phenotypes in bees. The social evolutionary consequences of climate change will be complex and heterogeneous, depending on such factors as local climate and plasticity of social traits. Many contexts will see an increase in the frequency of eusocial nesting as warming temperatures accelerate development and expand the temporal window for rearing a worker brood. More broadly, climate-mediated shifts in the abiotic and biotic selective environments will alter the costs and benefits of social living in different contexts, with cascading impacts at the population, community and ecosystem levels.

The neonicotinoid acetamiprid reduces larval and adult survival in honeybees (Apis mellifera) and interacts with a fungicide mixture

Plant protection products (PPPs), which are frequently used in agriculture, can be major stressors for honeybees. They have been found abundantly in the beehive, particularly in pollen. Few studies have analysed effects on honeybee larvae, and little is known about effects of insecticide-fungicide-mixtures, although this is a highly realistic exposure scenario. We asked whether the combination of a frequently used insecticide and fungicides would affect developing bees. Honeybee larvae (Apis mellifera carnica) were reared in vitro on larval diets containing different PPPs at two concentrations, derived from residues found in pollen. We used the neonicotinoid acetamiprid, the combined fungicides boscalid/dimoxystrobin and the mixture of all three substances. Mortality was assessed at larval, pupal, and adult stages, and the size and weight of newly emerged bees were measured. The insecticide treatment in higher concentrations significantly reduced larval and adult survival. Interestingly, survival was not affected by the high concentrated insecticide-fungicides-mixture. However, negative synergistic effects on adult survival were caused by the low concentrated insecticide-fungicides-mixture, which had no effect when applied alone. The lower concentrated combined fungicides led to significantly lighter adult bees, although the survival was unaffected. Our results suggest that environmental relevant concentrations can be harmful to honeybees. To fully understand the interaction of different PPPs, more combinations and concentrations should be studied in social and solitary bees with possibly different sensitivities.

Impact of the annular solar eclipse on December 26, 2019 on the foraging visits of bees

Solar eclipse has remarkable effect on behavior of animals. South India experienced a 97% magnitude annular eclipse on December 26, 2019 during 08:04–11:04 h with the totality phase appeared during 09:25–09:30 h. We investigated whether the foraging activity of the bees was limited by the eclipse, what bees are affected most, and which part of the eclipse was critical for bee activities to understand how a group of insects that rely the Sun, the sunlight, and the sun rays for their navigation and vision behaves to the eclipse. We opted to watch the bees in their foraging ground, and selected the natural flower populations of Cleome rutidosperma, Hygrophila schulli, Mimosa pudica, and Urena sinuata—some of the bee-friendly plants—to record the visitor richness and visitation rate on the flowers on eclipse and non-eclipse days and during the hour of totality phase and partial phase of the eclipse. Fewer flower-visiting species were recorded on the eclipse day than on the non-eclipse days, but in the period of totality, very few bee species were active, and limited their activity to only one population of C. rutidosperma. Visits of honey bees and stingless bees were affected most, but not that badly of solitary bees and carpenter bees. Bees, particularly the social bees use Sun for navigation and deciphering information on forage sources to fellow workers. The eclipse, like for many other animals, might hamper bees’ orientation, vision, and flight.

Use of Social Bees and Solitary Bees as Bioindicators of Environmental Contamination

With an emphasis on the biology of bee nesting, their ecological functions, and their efficacy in determining heavy metal pollution, this review paper summarises current research on bees as bioindicators of environmental contamination. Review brought attention to the solitary nesting behaviours of species such as Epanthidium tigrinum and Megachile cephalotes, highlighting their preference for particular materials for their nests as well as their function as pollinators. It was investigated how resin serves many purposes in defense, disease resistance, and nest building, highlighting its ecological value. One paper talked about the abilities of wasps and bees, demonstrating how they interact with one another inside the nests and how sensitive they are to changes in their surroundings. Honeybees have been found to be useful bioindicators for pesticides and heavy metals because they incorporate toxins from the air, soil, and water into their products. Additionally, bee pollen has shown to be a trustworthy marker of pesticide residues, indicating the degree of local pollution. Furthermore, research examining the levels of heavy metals in bee products across different areas highlighted the potential of honey to serve as a biomonitor for pollution in the environment. One of the reviewed studies specifically measured heavy metal concentrations in pollen and Osmia bicornis L. bees across different habitats, demonstrating how variations in habitat proximity to pollution sources affect contamination levels, thereby underscoring the utility of solitary bees as effective bioindicators. The precise methods for assembling trap nests and gathering samples offered useful information for researching community dynamics and trophic relationships. Overall, this review summarises research showing that social bees and solitary bees are important for assessing the health of ecosystems and provide useful tools for environmental monitoring.

Effects of heat shocks, heat waves, and sustained warming on solitary bees

Along with higher average temperatures, global climate change is expected to lead to more frequent and intense extreme heat events, and these different types of warming are likely to differ in their effects on bees. Although solitary bees comprise >75% of bee species, and despite their ecological and economic value as pollinators, a literature search revealed that only 8% of studies on bee responses to warming involve solitary bees. Here we review studies that have addressed how solitary bees are affected by three main types of warming that vary in magnitude and duration: heat shocks, heat waves, and sustained warming. We focus on direct physiological and behavioral effects of warming on solitary bees, rather than the underlying mechanisms. We find that heat shocks have received little attention in solitary bees both in terms of number of studies and relative to social bees, and all of those studies examine the effects of heat shocks on a single genus, Megachile. This work has shown that heat-shocked eggs, larvae, and pupae tend to upregulate heat shock protein genes, while heat shock at the adult stage can increase mortality in male bees, potentially altering population sex ratios. We find that solitary bee responses to heat waves have received even less study, but the few studies suggest that these events can increase larval mortality and slow development time, and that bees may not be able to physiologically acclimate to heat wave conditions by increasing their critical thermal maxima. Finally, sustained warming, which has been relatively well-studied in solitary bees, can speed development rate, reduce body mass, increase mortality, and alter foraging behavior. Our review reveals knowledge gaps in the effects of heat shocks and heat waves on solitary bees and, more broadly, in the responses of unmanaged solitary bees to warming. To improve our ability to anticipate the consequences of climate change for these critical pollinators, we encourage research on solitary bee thermal responses that examines short-term, extreme warming and incorporates greater ecological realism and complexity.

Age-related task progression in two Australian Tetragonula stingless bees

Stingless bees are a widespread group of highly social bees found in tropical regions throughout much of the world. Despite an impressive diversity, relatively little is known about worker behaviour and division of labour. In this study, we investigate the progression of colony tasks over the lifespan of worker bees in colonies of the two most commonly kept Australian species: Tetragonula carbonaria and T. hockingsi. We marked cohorts of 25–100 newly emerged female bees with a paint dot and released them back into colonies housed in observation hives before recording twice weekly behaviours of marked bees within the nest. Foragers were observed through a clear plastic entrance tube. We replicated this with 5–6 marked cohorts across three colonies for each species. We found the two species were similar to each other in the frequency and age distribution of behaviours. Young worker bees were mostly found cleaning, filling or constructing brood cells and collecting honey from food pots. Middle aged bees were more likely to build or maintain food pots or supporting structures, with guarding and foraging occupying the oldest bees. There was, however, significant overlap in timing of tasks. Moreover, fast cohorts progressed to foraging in less than half the time of the slowest cohorts. Despite subtle differences between our Tetragonula species and other stingless bees, it adds to the evidence that progression from safe to risky jobs with age is an ancestral feature shared across stingless bees, and has similarities to honeybees despite an independent evolutionary origin.

Pollinator activity and flowering in agricultural weeds in Sweden.

The extent to which weeds in arable land are useful to pollinators depends in part on the temporal pattern of flowering and insect flight activity. We compiled citizen science data on 54 bees and hoverflies typical of agricultural areas in southern Sweden, as well as 24 flowering weed species classified as pollinator-friendly in the sense that they provide nectar and/or pollen to pollinators. The flight periods of the bees and hoverflies varied greatly, but there were also some consistent differences between the four groups studied. The first group to fly were the early flying solitary bees (7 species), followed by the social bees (18 species). In contrast, other solitary bees (11 species) and hoverflies (22 species) flew later in the summer. Solitary bees had the shortest flight periods, while social bees and hoverflies had longer flight periods. Flowering of weed species also varied greatly between species, with weeds classified as winter annuals (e.g., germinating in autumn) starting early together with germination generalists (species that can germinate in both autumn and spring). Summer annuals (spring germinators) and perennials started flowering about a month later. Germination generalists had a much longer flowering period than the others. Weekly pollinator records were in most cases significantly explained by weed records. Apart from early flying solitary bees, all models showed strong positive relationships. The overall best explanatory variable was the total number of weeds, with a weight assigned to each species based on its potential as a nectar/pollen source. This suggests that agricultural weeds in Sweden provide a continuous potential supply of nectar and pollen throughout the flight season of most pollinators.

Extensive loss of forage diversity in social bees owing to flower constancy in simulated environments.

Many bees visit just one flower species during a foraging trip, i.e. they show flower constancy. Flower constancy is important for plant reproduction but it could lead to an unbalanced diet, especially in biodiversity-depleted landscapes. It is assumed that flower constancy does not reduce dietary diversity in social bees, such as honeybees or bumblebees, but this has not yet been tested. We used computer simulations to investigate the effects of flower constancy on colony diet in plant species-rich and species-poor landscapes. We also explored if communication about food sources, which is used by many social bees, further reduces forage diversity. Our simulations reveal an extensive loss of forage diversity owing to flower constancy in both species-rich and species-poor environments. Small flower-constant colonies often discovered only 30-50% of all available plant species, thereby increasing the risk of nutritional deficiencies. Communication often interacted with flower constancy to reduce forage diversity further. Finally, we found that food source clustering, but not habitat fragmentation impaired dietary diversity. These findings highlight the nutritional challenges flower-constant bees face in different landscapes and they can aid in the design of measures to increase forage diversity and improve bee nutrition in human-modified landscapes.

Tropical and montane Apis cerana show distinct dance-distance calibration curves.

Social bees have evolved sophisticated communication systems to recruit nestmates to newly found food sources. As foraging ranges can vary from a few hundred meters to several kilometers depending on the environment or season, populations of social bee species living in different climate zones likely show specific adaptations in their recruitment communication. Accordingly, studies in the western honey bee, Apis mellifera, demonstrated that temperate populations exhibit shallower dance-calibration curves compared with tropical populations. Here, we report the first comparison of calibration curves for three Indian Apis cerana lineages: the tropical Apis indica, and the two montane Himalayan populations Apis cerana cerana (Himachal Pradesh) and Apis cerana kashmirensis (Jammu and Kashmir). We found that the colonies of the two montane A. cerana populations show dance-distance calibration curves with significantly shallower slopes than those of the tropical A. indica. Next, we transferred A. c. cerana colonies to Bangalore (∼ 2600 km away) to obtain calibration curves in the same location as A. indica. The common garden experiment confirmed this difference in slopes, implying that the lineages exhibit genetically fixed differences in dance-distance coding. However, the slopes of the calibration curves of the transferred A. c. cerana colonies were also significantly higher than those of the colonies tested in their original habitat, indicating an important effect of the environment. The differences in dance-distance coding between temperate and tropical A. cerana lineages resemble those described for Apis mellifera, suggesting that populations of both species independently evolved similar adaptations.

Hymenopteran Fauna of Andanan Watershed Forest Reserve in Caraga Region, Philippines

The hymenopteran fauna plays a crucial role in the ecosystem, serving as primary pollinators and acting as biological controls essential in the interrelationships in the community. This study assessed various groups of Hymenoptera occurring in Andanan Watershed Forest Reserve from collected samples through sweeping, light trapping, and opportunistic sampling. A total of 36 species of hymenopterans were identified, belonging to 30 genera, 20 subfamilies, 11 families, and four superfamilies. One genus of Scoliidae – Phalerimeris, with one species, P. aurulenta, and a single species of Liacos – L. semperi, are reported in the Philippines for the first time, while the sphecine wasp Isodontia is a new record to Mindanao island. Formicidae is the most abundant family comprising 40% of all the collected individuals. Other groups with significant numbers include the families Apidae and Vespidae. Additional families present in the area include social apoid bees Halictidae and solitary bees Megachilidae. Predatory apoid wasps Crabronidae and Sphecidae, predatory vespoid wasps Pompilidae, Mutillidae, Scoliidae, and the parasitoid wasps Ichneumonidae were also reported. Anthropogenic activities and human interventions are also observed in the area, which may pose threats to the diversity of hymenopteran fauna in the forest reserve.

The small hive beetle’s capacity to disperse over long distances by flight

The spread of invasive species often follows a jump-dispersal pattern. While jumps are typically fostered by humans, local dispersal can occur due to the specific traits of a species, which are often poorly understood. This holds true for small hive beetles (Aethina tumida), which are parasites of social bee colonies native to sub-Saharan Africa. They have become a widespread invasive species. In 2017, a mark-release-recapture experiment was conducted in six replicates (A–F) using laboratory reared, dye-fed adults (N = 15,690). Honey bee colonies were used to attract flying small hive beetles at fixed spatial intervals from a central release point. Small hive beetles were recaptured (N = 770) at a maximum distance of 3.2 km after 24 h and 12 km after 1 week. Most small hive beetles were collected closest to the release point at 0 m (76%, replicate A) and 50 m (52%, replicates B to F). Temperature and wind deviation had significant effects on dispersal, with more small hive beetles being recaptured when temperatures were high (GLMM: slope = 0.99, SE = 0.17, Z = 5.72, P < 0.001) and confirming the role of wind for odour modulated dispersal of flying insects (GLMM: slope = − 0.39, SE = 0.14, Z = − 2.90, P = 0.004). Our findings show that the small hive beetles is capable of long-distance flights, and highlights the need to understand species specific traits to be considered for monitoring and mitigation efforts regarding invasive alien species.