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Effects of pollen quality and genotype on the dance of foraging honey bees.

Animals assess the quality and quantity of food and choose among different foods based on these assessments. We explored whether there was genetic variation for assessment of pollen quality by foraging honey bees, Apis mellifera. Honey bees derived from two genotypic strains foraged for pollen of varying quality from a petri dish placed inside an outdoor flight cage. The strains were the result of a colony-level, two-way selection on amount of stored pollen. We used the forager's round dance to quantify the assessments of pollen quality by individually marked worker bees. The dance rate (number of 180 degrees turns per minute) and the probability of dancing were each greater when bees foraged for pure pollen compared with a lower-quality mixture of pollen and alpha-cellulose (1:1 by volume). Bees from the high-pollen genotypic strain had a higher dance rate than those from the low-pollen strain, suggesting different assessments. Bees from the low-pollen strain, however, had a higher probability of dancing than did bees from the high-pollen strain. Dance duration was not affected by a bee's strain or by the quality of pollen. We conclude that the dance rate may be used to quantify a forager's subjective evaluation of pollen quality and that this evaluation has a genetic component. Our results also suggest that the dance may function at the colony level to recruit bees to more profitable pollen sources. Copyright 1998 The Association for the Study of Animal Behaviour.

Journal Article↗

Comb wax mediates the acquisition of nest-mate recognition cues in honey bees.

Honey bees, Apis mellifera, acquire nest-mate recognition cues from wax, the predominant material used in nest construction. Exposure of a newly emerged worker bee to wax-comb substrate significantly reduced the acceptability of that worker to sister bees. Cues acquired from the comb provided colony-specific information about the identity of worker bees; moreover, the effect of comb exposure has been previously shown to override individually produced cues. Food odors (anise oil), when dissolved in paraffin wax, affected worker-recognition characteristics but food odors did not affect these characteristics when fed to bees in sugar candy. Paraffin wax alone did not affect the recognition cues of bees, showing that the wax can be a neutral medium for the transmission of cues. The wax comb in the colony and the hydrocarbon outer layer of the bee cuticle may be a continuous medium for any hydrocarbon-soluble substances used by honey bees in nest-mate recognition; if so, a mechanism by which environmental cues are acquired by honey bees is provided.

Journal Article↗

Effect of honey bee venom on proliferation of K1735M2 mouse melanoma cells in-vitro and growth of murine B16 melanomas in-vivo.

Bee venom has been reported to exhibit antitumour activity in-vitro and in-vivo. Apoptosis, necrosis and lysis of tumour cells were suggested as possible mechanisms by which bee venom inhibited tumour growth. The aim of this study was to investigate potential mechanisms by which bee venom inhibits K1735M2 mouse melanoma cells in-vitro and B16 melanoma, a transplantable solid melanoma in C57BL/6 mice, in-vivo. The proliferation of K1735M2 cells in-vitro was inhibited by bee venom in a concentration- and time-dependent manner. The inhibition was indicated by the arrest of the cell cycle at the G1 stage, as detected by flow cytometric measurements. The bee venom induced apoptosis-like cell death as identified by histological observations and by DNA fragmentation. In the in-vivo experiments, the bee venom (1.0, 3.0, 9.0 mg kg-1 of body weight, on days 1-12) was injected intraperitoneally into mice 24 h after the mice were inoculated with B16 cells. Inhibition of the solid tumour was observed. Apoptosis of the K1735M2 cells was suggested as the possible mechanism by which bee venom inhibited cell proliferation and induced K1735M2 cell differentiation in-vitro. The in-vivo experiment indicated that bee venom could be used as a chemotherapeutic agent against malignant tumours.

Animals↗

Neutralization of bee venom lethality by immune serum antibodies.

The lethal effects of Africanized honey bee venom depend on the absorption of venom delivered during simultaneous sting attacks by large numbers of bees. The hypothesis that antibodies to whole bee venom and bee venom components could neutralize the lethal effect of bee venom was tested. Antibodies from beekeepers and immunized rabbits were incubated with bee venom and neutralization was studied by survival of intravenously injected mice. Beekeeper serum antibodies were found effective in protecting mice challenged with whole venom, and serum from rabbits immunized with phospholipase A2 (PLA2) was effective in protection against lethal effects of PLA2. Serum antibodies from rabbits immunized with whole venom or melittin were ineffective in neutralizing whole venom in vivo and had low titers in a venom enzyme-linked immunosorbent assay. The results suggest the need for development of more effective methods for raising antitoxic antibodies to bee venom components in other animals as a means of developing an antiserum that would be effective for treatment of human victims of multiple bee stings.

Animals↗

[Three cases of centipede allergy--analysis of cross reactivity with bee allergy].

BACKGROUND: We experienced three cases of patients who suffered from systemic urticaria and systemic symptoms such as general fatigue and dyspnea which occurred just after the sting of centipede. The result of prick test by centipede venom revealed positive reaction in all three patients, so we diagnosed the symptoms of them as immediate type allergic reaction against centipede venom. And more there have been some reports documented the relationship between centipede allergy and bee allergy, so we added the examination about bee allergy on these three patients. METHODS: The measurement of bee venom specific IgE was practiced on all three patients and intradermal skin test about bee venom was done only on one patient. Moreover we also practiced prick test of centipede venom against another three patients who were diagnosed as having bee allergy. RESULTS: All patients of centipede allergy showed positive reaction for the specific IgE antibody of Wasp and/or Honeybee and one patient who was practiced skin test also reacted positively against Wasp and Yellow Jacket venom. But none of three patients of bee allergy showed positive reaction against centipede venom. CONCLUSION: According to these results we suspected that there lies some relationship between centipede allergy and bee allergy. But it is supposed that only little involvement of centipede allergy was concerned among the patients of bee allergy. Until now there have been only a few reports as to the centipede allergy. But actually we guess it may be the phenomenon that could occur frequently.

Aged↗

Juvenile hormone and octopamine in the regulation of division of labor in honey bee colonies.

Forager honey bees have high circulating levels of juvenile hormone (JH) and high brain levels of octopamine, especially in the antennal lobes, and treatment with either of these compounds induces foraging. Experiments were performed to determine whether octopamine acts more proximally than JH to affect the initiation of foraging behavior. Bees treated with octopamine became foragers more rapidly than bees treated with the JH analog methoprene. Bees treated with methoprene showed an increase in antennal lobe levels of octopamine, especially after 12 days. Bees with no circulating JH (corpora allata glands removed) treated with octopamine became foragers in similar numbers to bees with intact corpora allata. These results suggest that JH affects the initiation of foraging at least in part by increasing brain levels of octopamine, but octopamine can act independently of JH. Effects of JH that are not related to octopamine also are possible, as bees treated with both octopamine and methoprene were more likely to become foragers than bees treated with only octopamine or methoprene.

Animals↗

Phylogenetic utility of the major opsin in bees (Hymenoptera: Apoidea): a reassessment.

Major opsin (LW Rh) DNA sequence has been reported to provide useful data for resolving phylogenetic relationships among tribes of corbiculate bees based on analyses of 502 bp of coding sequence. However, the corbiculate tribes are believed to be of Cretaceous age, and strong support for insect clades of this age from small data sets of nucleotide sequence data has rarely been demonstrated. To more critically assess opsin's phylogenetic utility we generated an expanded LW Rh data set by sequencing the same gene fragment from 52 additional bee species from 24 tribes and all six extant bee families. Analyses of this data set failed to provide substantial support for monophyly of corbiculate bees, for relationships among corbiculate tribes, or for most other well-established higher-level relationships among long-tongued bees. However, monophyly of nearly all genera and tribes is strongly supported, indicating that LW Rh provides useful phylogenetic signal at lower taxonomic levels. When our expanded LW Rh data set is combined with a morphological and behavioral data set for corbiculate bees, the results unambiguously support the traditional phylogeny of the corbiculate bee tribes: (Euglossini + (Bombini + (Meliponini + Apini))). This implies a single origin of advanced eusocial behavior among bees rather than dual origins, as proposed by several recent studies.

Animals↗

Seasonal changes in juvenile hormone titers and rates of biosynthesis in honey bees.

Honey bee colonies can respond to changing environmental conditions by showing plasticity in age related division of labor, and these responses are associated with changes in juvenile hormone. The shift from nest tasks to foraging has been especially well characterized; foraging is associated with high juvenile hormone titers and high rates of juvenile hormone biosynthesis, and can be induced prematurely in young bees by juvenile hormone treatment or by a shortage of foragers. However, very few studies have been conducted that study plasticity in division of labor under naturally occurring changes in the environment. To gain further insight into how the environment and juvenile hormone influence foraging behavior, we measured juvenile hormone titers and rates of biosynthesis in workers during times of the year when colony activity in temperature climates is reduced: late fall, winter, and early spring. Juvenile hormone titers and rates of biosynthesis decreased in foragers in the fall as foraging diminished and bees became less active. This demonstration of a natural drop in juvenile hormone confirms and extends previous findings when bees were experimentally induced to revert from foraging to within-hive tasks. In addition, endocrine changes in foragers in the fall are part of a larger seasonally related phenomenon in which juvenile hormone levels in younger, pre-foraging bees also decline in the fall and then increase the following spring as colony activity increases. The seasonal decline in juvenile hormone in foragers was mimicked in summer by placing a honey bee colony in a cold room for 8 days. This suggests that seasonal changes in juvenile hormone are not related to photoperiod changes, but rather to changes in temperature and/or colony social structure that in turn influence endocrine and behavioral development. We also found that active foragers in the late winter and early spring had lower juvenile hormone levels than active foragers in late spring. In light of recent findings of a possible link between juvenile hormone and neuroanatomical plasticity in the bee brain, these results suggest that bees can forage with low juvenile hormone, after previous exposure to some threshold level of juvenile hormone leads to changes in brain structure.

Analysis of Variance↗

A stingless bee (Melipona seminigra) uses optic flow to estimate flight distances.

Foragers of a stingless bee, Melipona seminigra, are able to use the optic flow experienced en route to estimate flight distance. After training the bees to collect food inside a flight tunnel with black-and-white stripes covering the side walls and the floor, their search behavior was observed in tunnels lacking a reward. Like honeybees, the bees accurately estimated the distance to the previously offered food source as seen from the sections of the tunnel where they turned around in search of the food. Changing the visual flow by decreasing the width of the flight tunnel resulted in the underestimation of the distance flown. The removal of image motion cues either in the ventral or lateral field of view reduced the bees' ability to gauge distances. When the feeder inside the tunnel was displaced together with the bees feeding on it while preventing the bee from seeing any image motion during the displacement the bees experienced different distances on their way to the food source and during their return to the nest. In the subsequent test the bees searched for the food predominantly at the distance associated with their return flight.

Animal Communication↗

A stingless bee uses labial gland secretions for scent trail communication ( Trigona recursa Smith 1863).

The pheromones used by several species of stingless bees for scent trail communication are generally assumed to be produced by the mandibular glands. Here we present strong evidence that in Trigona recursa these pheromones originate from the labial glands, which are well developed in the heads of foragers. Analysis of the behavior involved in scent marking shows that a bee extends her proboscis and rubs it over the substrate. A single scent marking event lasts for 0.59+/-0.21 s while the bee runs a stretch of 1.04+/-0.37 cm on a leaf. According to choice experiments the bees are attracted by a feeder baited with labial gland extract (84.2+/-6% of the bees choose this feeder) but repelled from a feeder baited with mandibular gland extract (only 27.5+/-13.1% of the bees choose this feeder). They do not discriminate between two clean feeders (49.6+/-3% of the bees at a feeder). 87+/-5.1% of bees already feeding leave the feeder after the application of mandibular gland extract whereas only 6.2+/-4.9% and 2.6+/-4% do so when labial gland extract or pure solvent was applied.

Animal Communication↗

Responsiveness to sucrose and habituation of the proboscis extension response in honey bees.

In honey bees, complex behaviours such as associative learning correlate with responsiveness to sucrose. In these behaviours, the subjective evaluation of a sucrose stimulus influences the behavioural performance. Habituation is a well-known form of non-associative learning. In bees, the proboscis extension response can be habituated by repeatedly stimulating the antennae with a low sucrose concentration. A high sucrose concentration can dishabituate the response. This study tests whether habituation correlates with responsiveness to sucrose in bees of different behavioural states and in bees which are habituated with different sucrose concentrations. Habituation and dishabituation in newly emerged bees, 5-day-old bees and foragers strongly correlated with responsiveness to sucrose. Bees with high responsiveness to sucrose displayed a lower degree of habituation and showed greater dishabituation than bees with low responsiveness. The degree of habituation and dishabituation also depended on the concentration of the habituation stimulus. These experiments demonstrate for the first time in a non-associative learning paradigm that the subjective strength of a sucrose stimulus determines the behavioural performance. Non-associative learning shares this property with associative learning, which suggests that the two processes might rely on similar neural mechanisms.

Animals↗

Octopamine influences division of labor in honey bee colonies.

Forager honey bees have higher brain levels of octopamine than do bees tending larvae in the hive. To test the hypothesis that octopamine influences honey bee division of labor we treated bees orally with octopamine or its immediate precursor tyramine and determined whether these treatments increased the probability of initiating foraging. Octopamine treatment significantly elevated levels of octopamine in the brain and caused a significant dose-dependent increase in the number of new foragers. This effect was seen for precocious foragers in single-cohort colonies and foragers in larger colonies with more typical age demographies. Tyramine treatment did not increase the number of new foragers, suggesting that octopamine was exerting a specific effect. Octopamine treatment was effective only when given to bees old enough to forage, i.e., older than 4 days of age. Treatment when bees were 1-3 days of age did not cause a significant increase in the number of new foragers when the bees reached the minimal foraging age. These results demonstrate that octopamine influences division of labor in honey bee colonies. We speculate that octopamine is acting in this context as a neuromodulator.

Adrenergic alpha-Agonists↗

Efficacy of strips coated with Metarhizium anisopliae for control of Varroa destructor (Acari: Varroidae) in honey bee colonies in Texas and Florida.

Strips coated with conidia of Metarhizium anisopliae (Metschinkoff; Deuteromycetes: Hyphomycetes) to control the parasitic mite, Varroa destructor (Anderson and Trueman) in colonies of honey bees, Apis mellifera (Hymenoptera: Apidae) were compared against the miticide, tau-fluvalinate (Apistan) in field trials in Texas and Florida (USA). Apistan and the fungal treatments resulted in successful control of mite populations in both locations. At the end of the 42-day period of the experiment in Texas, the number of mites per bee was reduced by 69-fold in bee hives treated with Apistan and 25-fold in hives treated with the fungus; however mite infestations increased by 1.3-fold in the control bee hives. Similarly, the number of mites in sealed brood was 13-fold and 3.6-fold higher in the control bee hives than in those treated with Apistan and with the fungus, respectively. Like the miticide Apistan, the fungal treatments provided a significant reduction of mite populations at the end of the experimental period. The data from the broodless colonies treated with the fungus indicated that optimum mite control could be achieved when no brood is being produced, or when brood production is low, such as in the early spring or late fall. In established colonies in Florida, honey bee colony development did not increase under either Apistan or fungal treatments at the end of the experimental period, suggesting that other factors (queen health, food source, food availability) play some major role in the growth of bee colonies. Overall, microbial control of Varroa mites with fungal pathogens could be a useful component of an integrated pest management program for the honey bee industry.

Animals↗

New risk assessment approach for systemic insecticides: the case of honey bees and imidacloprid (Gaucho).

The procedure to assess the risk posed by systemic insecticides to honey bees follows the European Directives and depends on the determination of the Hazard Quotient (HQ), though this parameter is not adapted to these molecules. This paper describes a new approach to assess more specifically the risk posed by systemic insecticides to honey bees with the example of imidacloprid (Gaucho). This approach is based on the new and existing chemical substances Directive in which levels of exposure (PEC, Predicted Exposure Concentration) and toxicity (PNEC, Predicted No Effect Concentration) are compared. PECs are determined for different categories of honey bees in relation to the amounts of contaminated pollen and nectar they might consume. PNECs are calculated from data on acute, chronic, and sublethal toxicities of imidacloprid to honey bees, to which selected assessment factors are applied. Results highlight a risk for all categories of honey bees, in particular for hive bees. These data are discussed in the light of field observations made on honey bee mortalities and disappearances. New perspectives are given to better determine the risk posed by systemic insecticides to honey bees.

Animals↗

The activities of fructose diphosphatase in flight muscles from the bumble-bee and the role of this enzyme in heat generation.

1. The maximum catalytic activities of fructose diphosphatase from flight muscles of bumble-bees (Bombus spp.) are at least 30-fold those reported for the enzyme from other tissues. The maximum activity of fructose diphosphatase in the flight muscle of any particular bee is similar to that of phosphofructokinase in the same muscle, and the activity of hexokinase is similar to or greater than the activity of phosphofructokinase. There is no detectable activity of glucose 6-phosphatase and only a very low activity of glucose 6-phosphate dehydrogenase in these muscles. The activities of both fructose diphosphatase and phosphofructokinase vary inversely with the body weight of the bee, whereas that of hexokinase is relatively constant. 2. There is no significant hydrolysis of fructose 1-phosphate, fructose 6-phosphate, glucose 1,6-diphosphate and glycerol 3-phosphate by extracts of bumble-bee flight muscle. 3. Fructose 1,6-diphosphatase from bumble-bee flight muscle and from other muscles is inhibited by Mn(2+) and univalent cations; the potency of inhibition by the latter varies in the order Li(+)>Na(+)>K(+). However, the fructose diphosphatase from bumble-bee flight muscle is different from the enzyme from other tissues in that it is not inhibited by AMP. 4. The contents of ATP, hexose monophosphates, fructose diphosphate and triose phosphates in bumble-bee flight muscle showed no significant changes between rest and flight. 5. It is proposed that both fructose diphosphatase and phosphofructokinase are simultaneously active and catalyse a cycle between fructose 6-phosphate and fructose diphosphate in resting bumble-bee flight muscle. Such a cycle would produce continuous hydrolysis of ATP, with the release of energy as heat, which would help to maintain the thoracic temperature during rest periods at a level adequate for flight.

Adenosine Monophosphate↗

Secondary heat, but not mechanical, hyperalgesia induced by subcutaneous injection of bee venom in the conscious rat: effect of systemic MK-801, a non-competitive NMDA receptor antagonist.

Subcutaneous (s.c.) administration of bee venom into the plantar surface of one hind paw in rats has been found to produce an immediate single phase of persistent spontaneous nociceptive responses (continuously flinching, licking or lifting the injected paw) for 1-2 h accompanied by a 72-96 hour period of primary heat and mechanical hyperalgesia in the injection site and a spread of heat, but not mechanical, hyperalgesia in the non-injected hind paw (Chen et al., 1999b). To gain insight into the underlying mechanisms of the bee venom-induced hyperalgesia in particular, we further identified a heat, but not mechanical, hyperalgesia in an area (paw pad) distant from the injection site induced by s.c. injection of bee venom into the posterior leg 0.8-1.2 cm proximal to the heel measured by paw withdrawal reflex to radiant heat or von Frey monofilament stimuli in conscious rats. In the bee venom-treated hind limb, however, significant reduction in both thermal latency and mechanical threshold of withdrawal reflex was identified for a period of more than 96 h in the heel with a similar characteristic to the primary heat and mechanical hyperalgesia identified in the injection site previously. The time course of the heat hyperalgesia identified in the paw pad of the bee venom-treated side was shorter and lasted for less than 48 h, which was in parallel with the reduction in thermal latency of the withdrawal reflex identified in the non-injected hind paw. Moreover, pre- or post-treatment with a single dose of MK-801 (0.01 mg/kg, i.p.), a non-competitive N-methyl-D-aspartate (NMDA) receptor antagonist, completely blocked the occurrence, and reversed the established process of the heat hyperalgesia identified in either the bee venom-treated or non-treated paw pads, while the same treatments with the drug did not produce any influence upon the development and maintaining of the heat and mechanical hyperalgesia identified in the heel of the injected hind limb. Taken together with our previous results following s.c. intraplantar bee venom injection, we conclude that: (1) in addition to the well-identified primary heat and mechanical hyperalgesia in the injection site and its adjacent area, s.c. bee venom is also able to produce a secondary heat hyperalgesia in a region distant from the injection site which has a similar characteristic to the contralateral heat hyperalgesia; (2) NMDA receptors are involved in either development or maintenance of the secondary and the contralateral heat hyperalgesia, but without any role in those processes of the primary heat and mechanical hyperalgesia; (3) the secondary heat hyperalgesia seen in the injected hind limb is likely to share the same neural mechanisms with that identified in the non-injected side via co-activation of NMDA receptors.

Animals↗

Differential roles of spinal neurokinin 1/2 receptors in development of persistent spontaneous nociception and hyperalgesia induced by subcutaneous bee venom injection in the conscious rat.

To evaluate the roles of spinal neurokinin receptors in the development of persistent nociception and hyperalgesia to thermal and mechanical stimuli induced by subcutaneous (s.c.) bee venom injection, effects of intrathecal (i.t.) pre- or post-treatment with a non-selective antagonist of (NK1/2) receptors, [D-Arg1,D-Trp7,9,Leu11] substance P (spantide), and a selective NK3 receptor antagonist, (S)-(N)-(1-(3-(1-benzoyl-3-(3,4-dichlorophenyl) piperidin-3-yl)propyl)-4-phenylpiperidin-4-yl)-N-methyl acetamide (SR142801) were assessed in conscious rat. Injection of bee venom s.c. into the plantar surface of one hind paw resulted in a pathological pain phenomenon characterized by a 1-2 h single phase of persistent spontaneous nociceptive behaviors (continuously flinching the injected paw) and a 72-96 h profound primary thermal and mechanical hyperalgesia in the injection site and a secondary thermal hyperalgesia in the non-injected hindpaw. Pre-treatment with spantide i.t. at 0.05 microg, 0.5 microg and 5 microg produced a dose-related suppression of the bee venom-induced flinching reflex during the whole time course and the inhibitory rate was 24 +/- 12.60% (35.38 +/- 4.12 flinches/5 min, n=5), 48 +/- 6.75% (24.53 +/- 2.90 flinches/5 min, n=5) and 60 +/- 7.69% (18.88 +/- 3.58 flinches/5 min, n=5) respectively when compared with the saline control group (46.80 +/- 2.60 flinches/5 min, n=5). Post-treatment of spantide i.t. at the highest dose (5 microg) used in the present study 5 min after bee venom injection also produced a 49% suppression of the flinching reflex in the control group [post-spantide vs saline: 19.42 +/- 3.15 (n=5) vs 38.42 +/- 3.25 flinches/5 min (n=5)]. Moreover, i.t. pre-treatment with 5 microg spantide partially prevented the primary and secondary thermal hyperalgesia from occurring, while it did not show any influence on the development of primary mechanical hyperalgesia. Neither the established thermal nor mechanical hyperalgesia identified in the above sites was affected by i.t. post-treatment with the same dose of spantide 3 h after bee venom injection. Pre and post-treatment of SR142801 did not produce any significant effect on the bee venom-induced spontaneous pain and thermal and mechanical hyperalgesia. Our present result suggests that activation of spinal NK1/2 receptors is involved in both induction and maintenance of the persistent spontaneous nociception, while it is only involved in induction of the primary and secondary thermal, but not primary mechanical hyperalgesia induced by s.c. bee venom injection. The spinal NK3 receptor seems not likely to be involved in the bee venom-induced behavioral response characterized by spontaneous pain and thermal and mechanical hyperalgesia.

Analgesics↗

Pollination of Oncocyclus irises (Iris: Iridaceae) by night-sheltering male bees.

Irises in the section Oncocyclus (Siems.) Baker ( IRIS: Iridaceae) grow throughout the Middle East and have large and dark-coloured flowers but no nectar reward available to flower visitors. Consequently, no reward-collecting pollinators have been observed visiting the flowers during daytime. The only visitors are solitary male bees ( Eucera spp.: Apidae) that enter the flowers at dusk and stay there overnight. Here we describe the mating system of Oncocyclus irises, and the role of night-sheltering male bees in their pollination system. Pollen viability in I. haynei on Mt. Gilboa was very high (>90%) throughout all floral life stages. Stigmas were receptive in buds and in open flowers, but not in older ones. Self-pollination yielded no fruits in three species, confirming complete self-incompatibility in Oncocyclus irises. On average, 1.9 flowers were visited by each male bee before it settled for the night in the last one. Moreover, Iris pollen was present on the dorsal side of 38.8% of males caught sheltering in flower models mounted near an I. atrofusca population, indicating that pollen is transferred between flowers by night-sheltering solitary male bees. We have surveyed 13 flowering populations of six Oncocyclus species for the presence of night-sheltering male bees as well as for fruit set. We found a positive correlation, indicating that sexual reproduction in Oncocyclus irises is dependent on night-sheltering solitary male bees. Based on their complete self-incompatibility, the absence of nectar-collecting visitors during the day, and the transfer of pollen grains by the night-sheltering solitary male bees, we conclude that fertilization of Oncocyclus irises is totally dependent on pollination by night-sheltering solitary male bees.

Animals↗