Essential role of papillae flexibility in nectar capture by bees.

Many bees possess a tongue resembling a brush composed of a central rod (glossa) covered by elongated papillae, which is dipped periodically into nectar to collect this primary source of energy. In vivo measurements show that the amount of nectar collected per lap remains essentially constant for sugar concentrations lower than 50% but drops significantly for a concentration around 70%. To understand this variation of the ingestion rate with the sugar content of nectar, we investigate the dynamics of fluid capture by Bombus terrestris as a model system. During the dipping process, the papillae, which initially adhere to the glossa, unfold when immersed in the nectar. Combining in vivo investigations, macroscopic experiments with flexible rods, and an elastoviscous theoretical model, we show that the capture mechanism is governed by the relaxation dynamics of the bent papillae, driven by their elastic recoil slowed down through viscous dissipation. At low sugar concentrations, the papillae completely open before the tongue retracts out of nectar and thus, fully contribute to the fluid capture. In contrast, at larger concentrations corresponding to the drop of the ingestion rate, the viscous dissipation strongly hinders the papillae opening, reducing considerably the amount of nectar captured. This study shows the crucial role of flexible papillae, whose aspect ratio determines the optimal nectar concentration, to understand quantitatively the capture of nectar by bees and how physics can shed some light on the degree of adaptation of a specific morphological trait.

Antioxidative Propolis From Stingless Bees (Heterotrigona Itama) Preserves Endothelium-Dependent Aortic Relaxation of Diabetic Rats: The Role of Nitric Oxide and Cyclic Guanosine Monophosphate

Propolis from stingless bees (Heterotrigona itama) is a resinous compound that exhibits antihyperglycaemia, free radical scavenging, and cardioprotective properties. The effect of propolis on diabetic vessels has not been investigated. Thus, this research aimed to determine the effect of propolis supplementation on the level of antioxidants and its mechanism of action in the aorta of diabetic rats. Male Sprague-Dawley rats were divided into five groups (n=8/group): healthy (control), untreated diabetes (DM), metformin-treated diabetes (DM+M, 300 mg/kg/day metformin), propolis-treated diabetes (DM+P, 300 mg/kg/day propolis extract) and diabetes with combined treatment (DM+M+P, dosage as former). Oral supplementation was conducted for four weeks immediately upon successful induction of diabetes by streptozotocin (60 mg/kg, intraperitoneal injection). At the end of the study, the rats were euthanised, and thoracic aorta was processed into tissue homogenates to determine the levels of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase-1 (GPx-1) and soluble receptor for advanced glycation end-products (sRAGE). Aorta segments were harvested to examine their relaxation response towards graded concentration of acetylcholine (Ach; 10-8-10-4) M following precontraction with phenylephrine (PE; 10-6 M). Vasorelaxation towards a cumulative dose of propolis (0.01-1.00%) using PE-precontracted healthy aorta (n=6/experiments) was investigated under various simulated conditions: physiological buffer, L-NAME (10-4 M), methylene blue (10-5 M), indomethacin (10-5 M) and elevated glucose (25 mM). Propolis maintained antioxidative enzymes and sRAGE decoy molecules in the aortic tissue of the diabetic rats. The amelioration of diabetes-induced impairment of endothelium-dependent relaxation by propolis was mediated through the nitric oxide(NO)-cyclic guanosine monophosphate (cGMP) pathway. This non-clinical study reports vasoprotective property of propolis in diabetes mellitus.

Pollinator divergence and pollination isolation between hybrids with different floral color and morphology in two sympatric Penstemon species.

Differential visitation of pollinators due to divergent floral traits can lead to reproductive isolation via assortative pollen flow, which may ultimately be a driving force in plant speciation, particularly in areas of overlap. We evaluate the effects of pollinator behavioral responses to variation of intraspecific floral color and nectar rewards, on reproductive isolation between two hybrid flower color morphs (fuchsia and blue) and their parental species Penstemon roseus and P. gentianoides with a mixed-pollination system. We show that pollinators (bumblebees and hummingbirds) exhibit different behavioral responses to fuchsia and blue morphs, which could result from differential attraction or deterrence. In addition to differences in color (spectral reflectance), we found that plants with fuchsia flowers produced more and larger flowers, produced more nectar and were more visited by pollinators than those with blue flowers. These differences influenced the foraging behavior and effectiveness as pollinators of both bumblebees and hummingbirds, which contributed to reproductive isolation between the two hybrid flower color morphs and parental species. This study demonstrates how differentiation of pollination traits promotes the formation of hybrid zones leading to pollinator shifts and reproductive isolation. While phenotypic traits of fuchsia and red flowers might encourage more efficient hummingbird pollination in a mixed-pollination system, the costs of bumblebee pollination on plant reproduction could be the drivers for the repeated shifts from bumblebee- to hummingbird-mediated pollination.

Morphological specialization of heterantherous Rhynchanthera grandiflora (Melastomataceae) accommodates pollinator diversity.

The tropical Melastomataceae are characterized by poricidal anthers which constitute a floral filter selecting for buzz-pollinating bees. Stamens are often dimorphic, sometimes with discernible feeding and pollinating functions. Rhynchanthera grandiflora produces nectarless flowers with four short stamens and one long stamen; all anthers feature a narrow elongation with an upwards facing pore. We tested pollen transfer by diverse foraging bees and viability of pollen from both stamen types. The impact of anther morphology on pollen release direction and scattering angle was studied to determine the plant's reproductive strategy. Medium-sized to large bees sonicated flowers in a specific position, and the probability of pollen transfer correlated with bee size even among these legitimate visitors. Small bees acted as pollen thieves or robbers. Anther rostrum and pore morphology serve to direct and focus the pollen jet released by floral sonication towards the pollinator's body. Resulting from the ventral and dorsal positioning of the short and long stamens, respectively, the pollinator's body was widely covered with pollen. This improves the plant's chances of outcrossing, irrespective of which bee body part contacts the stigma. Consequently, R. grandiflora is also able to employ bee species of various sizes as pollen vectors. The strategy of spreading pollen all over the pollinator's body is rather cost-intensive but counterbalanced by ensuring that most of the released pollen is in fact transferred to the bee. Thus, flowers of R. grandiflora illustrate how specialized morphology may serve to improve pollination by a functional group of pollinators.

Pollen resources partitioning of stingless bees (Hymenoptera: Apidae) from the southern Atlantic forest

Meliponinae eusocial bees are among the most important pollinators in the Neotropics and their beekeeping has been growing as both recreational and economic activity. Information on the pollen preferences and niche overlap among species coexisting in the same location is still scarce. This study focused on the use of pollen resources by three native species of Meliponinae in the Atlantic Forest, Melipona quadrifasciata quadrifasciata (Lepeletier 1836), Scaptotrigona depilis (Moure 1942), and Tetragonisca angustula (Latreille 1811), at two different sites. The use of pollen resources was evaluated from reserves inside hives collected monthly between February 2015 and January 2016. It was also estimated the Mean Minimal Distance (Dm) traveled by the bees to obtain pollen. The bees differed regarding the diversity of pollen types, Dm, and proportion of pollen from different plant life-form. Local factor promoted differences only for Dm. M. q. quadrifasciata foraged a low diversity of pollen species and traveled greater distances with a higher proportion of trees plus palm species. Tetragonisca angustula foraged a higher diversity of pollen and flew shorter distances with a lower proportion of trees and palms. The species factor predominates over the local factor in the clustering pattern, based on pollen profile similarity.

Honey bee hairs and pollenkitt are essential for pollen capture and removal.

While insect grooming has been observed and documented for over one hundred years, we present the first quantitative analysis of this highly dynamic process. Pollinating insects, like honey bees, purposely cover themselves with millions of pollen particles that, if left ungroomed, would make sensing and controlled flight difficult. How do they get clean? We show that the hairs on insect eyes are tuned to the pollen they collect; namely, the hairs are spaced so that they suspend pollen above the body for easy removal by the forelegs. In turn, hair spacing on the foreleg dictates the leg's ability to store the pollen removed during each swipe. In tests with wax-covered honey bees, we show that hairy forelegs are necessary for pollen removal. Moreover, the viscous fluid found on the surface of pollen grains, or pollenkitt, greatly enhances adhesion. We find that bees accumulate twice as much pollen if pollenkitt is present. This study may help further understand pollination, as well as inform designs for mechanically-sensitive functional surfaces with micro- and nano-structures that are easier to keep clean.

Patterns of pollen and nectar foraging specialization by bumblebees over multiple timescales using RFID.

The ecological success of social insects is frequently ascribed to improvements in task performance due to division of labour amongst workers. While much research has focused on improvements associated with lifetime task specialization, members of colonies can specialize on a given task over shorter time periods. Eusocial bees in particular must collect pollen and nectar rewards to survive, but most workers appear to mix collection of both rewards over their lifetimes. We asked whether bumblebees specialize over timescales shorter than their lifetime. We also explored factors that govern such patterns, and asked whether reward specialists made more foraging bouts than generalists. In particular, we described antennal morphology and size of all foragers in a single colony and related these factors to each forager's complete foraging history, obtained using radio frequency identification (RFID). Only a small proportion of foragers were lifetime specialists; nevertheless, >50% of foragers specialized daily on a given reward. Contrary to expectations, daily and lifetime reward specialists were not better foragers (being neither larger nor making more bouts); larger bees with more antennal olfactory sensilla made more bouts, but were not more specialized. We discuss causes and functions of short and long-term patterns of specialization for bumblebee colonies.

Landscape Simplification Constrains Adult Size in a Native Ground-Nesting Bee.

Bees provide critical pollination services to 87% of angiosperm plants; however, the reliability of these services may become threatened as bee populations decline. Agricultural intensification, resulting in the simplification of environments at the landscape scale, greatly changes the quality and quantity of resources available for female bees to provision their offspring. These changes may alter or constrain the tradeoffs in maternal investment allocation between offspring size, number and sex required to maximize fitness. Here we investigate the relationship between landscape scale agricultural intensification and the size and number of individuals within a wild ground nesting bee species, Andrena nasonii. We show that agricultural intensification at the landscape scale was associated with a reduction in the average size of field collected A. nasonii adults in highly agricultural landscapes but not with the number of individuals collected. Small females carried significantly smaller (40%) pollen loads than large females, which is likely to have consequences for subsequent offspring production and fitness. Thus, landscape simplification is likely to constrain allocation of resources to offspring through a reduction in the overall quantity, quality and distribution of resources.

Palaearctic Hoplitis bees of the subgenus Platosmia (Megachilidae, Osmiini): biology, taxonomy and key to species.

Platosmia, a subgenus of the osmiine bee genus Hoplitis (Megachilidae), contains ten species, which are confined to desertic and semidesertic areas of the Palaearctic region. Analysis of female pollen loads and field observations indicate that several H. (Platosmia) species are strictly oligolectic on Reseda (Resedaceae) and possibly Hedysareae (Fabaceae), while others are mesolectic on both Reseda and Fabaceae. The few data available so far suggest that preexisting cavities in stones and rocks serve as nesting sites of H. (Platosmia). The taxonomic revision of H. (Platosmia) revealed the existence of an undescribed species from the Arabian peninsula, H. arabiae spec. nov.. Hoplitis incognita Zanden, 1996 and H. quarzazati (Zanden, 1998) are newly synonymized with H. maghrebensis (Zanden, 1992) and H. platalea (Warncke, 1990), respectively. Identification keys for all H. (Platosmia) species are given including the hitherto unknown male or female sex of three species.

Palaearctic Hoplitis bees of the subgenera Chlidoplitis and Megahoplitis (Megachilidae, Osmiini): biology, taxonomy and key to species.

Chlidoplitis and Megahoplitis are closely related Palaearctic subgenera of the osmiine bee genus Hoplitis (Megachilidae) containing nine and two species, respectively. Analysis of female pollen loads and field observations suggest that all species are pollen specialists. Whereas the H. (Chlidoplitis) species are probably all narrowly oligolectic and exclusively collect pollen on Allium (Alliaceae), Haplophyllum (Rutaceae), Reseda (Resedaceae), Teucrium (Lamiaceae), Trifolium (Fabaceae) or Hedysareae (Fabaceae), the H. (Megahoplitis) species show a close affinity to Carduoideae (Asteraceae) as pollen hosts. The few data available suggest that the H. (Chlidoplitis) species nest in preexisting insect burrows in the ground and use either chewed leaves or mud as nesting material. The nesting biology of the subgenus Megahoplitis remains unknown. The taxonomic revision of the subgenera Chlidoplitis and Megahoplitis revealed the existence of two undescribed species: H. (Chlidoplitis) haplophylli spec. nov. from southeastern Central Asia and Hoplitis (Chlidoplitis) allii spec. nov. from the Levant. Identification keys for the species of both subgenera are given including the hitherto unknown male of H. (Megahoplitis) bombiformis. 

Palaearctic Hoplitis bees of the subgenus Stenosmia (Megachilidae, Osmiini): biology, taxonomy and key to species.

Hoplitis bees of the Palaearctic subgenus Stenosmia (Megachilidae) inhabit deserts and semideserts between southern Spain and eastern Asia. They nest in excavated burrows in the soil and collect pollen from plant taxa that typically grow in desert areas, such as Frankenia (Frankeniaceae), Peganum (Nitrariaceae), Tamarix (Tamaricaceae) or Zygophyllum (Zygophyllaceae). The taxonomic revision of the subgenus Stenosmia revealed the existence of four undescribed species: Hoplitis desertorum spec. nov. from the Levant, H. crassipunctata spec. nov. and H. dispersipunctata spec. nov. from Central Asia, and H. gobiensis spec. nov. from the Gobi desert. Hoplitis denticulata (Zanden, 1992) is synonymized with H. jordanica (Warncke, 1991), and Hoplitis xinjiangense (Wu, 2004), formerly considered a H. (Stenosmia) species, is removed from this subgenus. The type species of the subgenus Stenosmia Michener is fixed as H. crassipunctata spec. nov., which has been misidentified as H. flavicornis (Morawitz, 1877). Keys for the identification of the H. (Stenosmia) species are given.

Fine-tuned bee-flower coevolutionary state hidden within multiple pollination interactions.

Relationships between flowers and pollinators are generally considered cases of mutualism since both agents gain benefits. Fine-tuned adaptations are usually found in the form of strict one-to-one coevolution between species. Many insect pollinators are, however, considered generalists, visiting numerous kinds of flowers, and many flower species (angiosperms) are also considered generalists, visited by many insect pollinators. We here describe a fine-tuned coevolutionary state of a flower-visiting bee that collects both nectar and pollen from an early spring flower visited by multiple pollinators. Detailed morphology of the bee proboscis is shown to be finely adjusted to the floral morphology and nectar production of the flower. Behavioral observations also confirm the precision of this mutualism. Our results suggest that a fine-tuned one-to-one coevolutionary state between a flower species and a pollinator species might be common, but frequently overlooked, in multiple flower-pollinator interactions.

Pollination ecology in the narrow endemic winter-flowering Primula allionii (Primulaceae).

Reduction of pollen flow can affect plant abundance and population viability and cause selection on plant mating system and floral traits. Little is known on the effect of this phenomenon in species naturally restricted to small and isolated habitats, that may have developed strategies to cope with long-term isolation and small population size. We investigated the pollination ecology of the endemic distylous winter-flowering P. allionii to verify the possible limitation of female fitness due to reduced pollinator visits. We recorded a higher production of pollen grains in long-styled morph, and a higher seed set in short-styled morph. The high intra-morph variability of sexual organ position may explain the hybridization phenomena allowing and easier intra-morph pollination. The fruit set is constant, although its winter-flowering period might decrease pollen transfer. Nevertheless, the lower competition for pollinators with neighbouring plants and the long-lasting anthesis may offset its reproductive success. Even if our results show no evidence of imminent threats, changes in plant-pollinator interactions might increase inbreeding, resulting in an increased extinction risk.

Genetics of reproduction and regulation of honeybee (Apis mellifera L.) social behavior.

Honeybees form complex societies with a division of labor for reproduction, nutrition, nest construction and maintenance, and defense. How does it evolve? Tasks performed by worker honeybees are distributed in time and space. There is no central control over behavior and there is no central genome on which selection can act and effect adaptive change. For 22 years, we have been addressing these questions by selecting on a single social trait associated with nutrition: the amount of surplus pollen (a source of protein) that is stored in the combs of the nest. Forty-two generations of selection have revealed changes at biological levels extending from the society down to the level of the gene. We show how we constructed this vertical understanding of social evolution using behavioral and anatomical analyses, physiology, genetic mapping, and gene knockdowns. We map out the phenotypic and genetic architectures of food storage and foraging behavior and show how they are linked through broad epistasis and pleiotropy affecting a reproductive regulatory network that influences foraging behavior. This is remarkable because worker honeybees have reduced reproductive organs and are normally sterile; however, the reproductive regulatory network has been co-opted for behavioral division of labor.

Individual lifetime pollen and nectar foraging preferences in bumble bees.

Foraging specialization plays an important role in the ability of social insects to efficiently allocate labor. However, relatively little is known about the degree to which individual bumble bees specialize on collecting nectar or pollen, when such preferences manifest, and if individuals can alter their foraging preferences in response to changes in the colony workforce. Using Bombus impatiens, we monitored all foraging visits made by every bee in multiple colonies and showed that individual foragers exhibit consistent lifetime foraging preferences. Based upon the distribution of foraging preferences, we defined three forager types (pollen specialists, nectar specialists, and generalists). In unmanipulated colonies, 16-36 % of individuals specialized (≥90 % of visits) on nectar or pollen only. On its first day of foraging, an individual's foraging choices (nectar only, pollen only, or nectar and pollen) significantly predicted its lifetime foraging preferences. Foragers that only collected pollen on their first day of foraging made 1.61- to 1.67-fold more lifetime pollen foraging visits (as a proportion of total trips) than foragers that only collected nectar on their first foraging day. Foragers were significantly larger than bees that stayed only in the nest. We also determined the effect of removing pollen specialists at early (brood present) or later (brood absent) stages in colony life. These results suggest that generalists can alter their foraging preferences in response to the loss of a small subset of foragers. Thus, bumble bees exhibit individual lifetime foraging preferences that are established early in life, but generalists may be able to adapt to colony needs.

Seasonal change in a pollinator community and the maintenance of style length variation in Mertensia fusiformis (Boraginaceae).

BACKGROUND AND AIMS: In sub-alpine habitats, patchiness in snowpack produces marked, small-scale variation in flowering phenology. Plants in early- and late-melting patches are therefore likely to experience very different conditions during their flowering periods. Mertensia fusiformis is an early-flowering perennial that varies conspicuously in style length within and among populations. The hypothesis that style length represents an adaptation to local flowering time was tested. Specifically, it was hypothesized that lower air temperatures and higher frost risk would favour short-styled plants (with stigmas more shielded by corollas) in early-flowering patches, but that the pollen-collecting behaviour of flower visitors in late-flowering patches would favour long-styled plants. METHODS: Floral morphology was measured, temperatures were monitored and pollinators were observed in several matched pairs of early and late populations. To evaluate effects of cold temperatures on plants of different style lengths, experimental pollinations were conducted during mornings (warm) and evenings (cool), and on flowers that either had or had not experienced a prior frost. The effectiveness of different pollinators was quantified as seed set following single visits to plants with relatively short or long styles. KEY RESULTS: Late-flowering populations experienced warmer temperatures than early-flowering populations and a different suite of pollinators. Nectar-foraging bumble-bee queens and male solitary bees predominated in early populations, whereas pollen-collecting female solitary bees were more numerous in later sites. Pollinators differed significantly in their abilities to transfer pollen to stigmas at different heights, in accordance with our prediction. However, temperature and frost sensitivity did not differ between long- and short-styled plants. Although plants in late-flowering patches tended to have longer styles than those in early patches, this difference was not consistent. CONCLUSIONS: Seasonal change in pollinator-mediated selection on style length may help maintain variation in this trait in M. fusiformis, but adaptation to local flowering time is not apparent. The prevalence of short styles in these populations requires further explanation.

Direct and indirect fossil records of megachilid bees from the Paleogene of Central Europe (Hymenoptera: Megachilidae).

Aside from pollen and nectar, bees of the subfamily Megachilinae are closely associated with plants as a source of materials for nest construction. Megachilines use resins, masticated leaves, trichomes and other plant materials sometimes along with mud to construct nests in cavities or in soil. Among these, the leafcutter bees (Megachile s.l.) are the most famous for their behaviour to line their brood cells with discs cut from various plants. We report on fossil records of one body fossil of a new non-leafcutting megachiline and of 12 leafcuttings from three European sites-Eckfeld and Messel, both in Germany (Eocene), and Menat, France (Paleocene). The excisions include the currently earliest record of probable Megachile activity and suggest the presence of such bees in the Paleocene European fauna. Comparison with extant leafcuttings permits the interpretation of a minimal number of species that produced these excisions. The wide range of size for the leafcuttings indirectly might suggest at least two species of Megachile for the fauna of Messel in addition to the other megachiline bee described here. The presence of several cuttings on most leaves from Eckfeld implies that the preferential foraging behaviour of extant Megachile arose early in megachiline evolution. These results demonstrate that combined investigation of body and trace fossils complement each other in understanding past biodiversity, the latter permitting the detection of taxa not otherwise directly sampled and inferences on behavioural evolution.

Laboratory-based X-ray phase-contrast imaging technique for material and medical science applications.

In-line X-ray phase-contrast imaging technique is an emerging method for the study of materials such as carbon fibers, carbon composite materials, polymers, etc. Similarly this technique is also well suited for the imaging of soft materials such as tissues, distinguishing between tumor and normal tissue. These represent the class of materials for which X-ray attenuation cross-section is very small. Thus this method promises a far better contrast for low X-ray absorbing substances than the conventional radiography method. We have set up an experimental facility using a combination of X-ray CCD detector and a microfocus X-ray source. This facility is dedicated to micro-imaging experiments such as microtomography and high-resolution phase-contrast experiments. In this paper, the results of X-ray phase-contrast imaging experiments are described.

Floral visitors of Chamaecrista debilis (Vogel) Irwin & Barneby (Fabaceae - Caesalpinioideae) at cerrado of Estação Ecológica de Jataí, São Paulo State, Brazil

Although Chamaecrista Moench genus is a very important source of pollen to bees in the Cerrado, this relationship is almost unknown. Within flower visitors of Ch. debilis, we found hymenopterans (Apidae) as the most abundants, but Coleoptera (Buprestidae) and Lepidoptera (Noctuidae) were also collected. Bees of great size are pointed out as effective pollinators of Cassiinae. Only five out of seventeen species of floral visitors of Ch. debilis sampled in cerrado, are indicated as possible pollinators, from which four species were not previously indicated in other papers.

Embora plantas do gênero Chamaecrista Moench representem importante fonte de pólen para abelhas do cerrado, essas relações são ainda pouco conhecidas. Entre os visitantes florais de Ch. debilis, os himenópteros (Apidae) são os mais abundantes, mas também são encontrados coleópteros (Buprestidae) e lepidópteros (Noctuidae). Abelhas de grande porte parecem ser os polinizadores efetivos dos Cassiinae no cerrado. Assim, das dezessete espécies visitantes florais de Ch. debilis, são indicadas apenas cinco espécies como potencialmente polinizadoras, dais quais quatro não foram registradas em outros estudos.

Dynamic range compression in the honey bee auditory system toward waggle dance sounds.

Honey bee foragers use a "waggle dance" to inform nestmates about direction and distance to locations of attractive food. The sound and air flows generated by dancer's wing and abdominal vibrations have been implicated as important cues, but the decoding mechanisms for these dance messages are poorly understood. To understand the neural mechanisms of honey bee dance communication, we analyzed the anatomy of antenna and Johnston's organ (JO) in the pedicel of the antenna, as well as the mechanical and neural response characteristics of antenna and JO to acoustic stimuli, respectively. The honey bee JO consists of about 300-320 scolopidia connected with about 48 cuticular "knobs" around the circumference of the pedicel. Each scolopidium contains bipolar sensory neurons with both type I and II cilia. The mechanical sensitivities of the antennal flagellum are specifically high in response to low but not high intensity stimuli of 265-350 Hz frequencies. The structural characteristics of antenna but not JO neurons seem to be responsible for the non-linear responses of the flagellum in contrast to mosquito and fruit fly. The honey bee flagellum is a sensitive movement detector responding to 20 nm tip displacement, which is comparable to female mosquito. Furthermore, the JO neurons have the ability to preserve both frequency and temporal information of acoustic stimuli including the "waggle dance" sound. Intriguingly, the response of JO neurons was found to be age-dependent, demonstrating that the dance communication is only possible between aged foragers. These results suggest that the matured honey bee antennae and JO neurons are best tuned to detect 250-300 Hz sound generated during "waggle dance" from the distance in a dark hive, and that sufficient responses of the JO neurons are obtained by reducing the mechanical sensitivity of the flagellum in a near-field of dancer. This nonlinear effect brings about dynamic range compression in the honey bee auditory system.