Chalepogenus | |
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Chalepogenus herbsti visiting Sisyrinchium striatum | |
Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Class: | Insecta |
Order: | Hymenoptera |
Family: | Apidae |
Tribe: | Tapinotaspidini |
Genus: | Chalepogenus |
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Observations of Chalepogenus from iNaturalist (as of October, 2023). |
The genus Chalepogenus, consisting of 21 species of solitary oil-collecting apid bees, demonstrates oligolecty by foraging on oil-producing flowers from the families Calceolariaceae, Iridaceae and Solanaceae. [1] [2] [3] These oil-flowers are abundant in South America, where Chalepogenus is endemic. [4] In contrast to honey bees, Chalepogenus species do not collect nectar; instead, they gather floral oil for various purposes, including provisioning their larvae, constructing nests, and sustaining foraging adult bees. [5] Although oil collection has been reported to be performed by females only, both males and females have specialised oil-collecting structures. [5]
Species of Chalepogenus are restricted to South America. [6]
Bees belonging to the genus Chalepogenus are relatively small compared to honey bees; their body size ranges from 4.2 to 10.0 millimetres. [7] [8] Chalepogenus species are hairy and exhibit diverse colouration, with some having a black integument (e.g. C. cocuccii ), and others displaying yellow markings on their head, thorax, legs, or metasoma (e.g. C. herbsti ). Additionally, certain species exhibit red colouring on their legs or metasoma (e.g. C. rufipes ), while others have bluish metallic reflections (e.g. C. caeruleus ). [7]
The oil-collecting structures (pad and comb) of Chalepogenus bees are covered by setae and are located on the posterior surface of the forebasitarsus. [2] [9] The bees exhibit interspecific variation based on the flower type they forage:
Chalepogenus oil-collecting bees pollinate plant species belonging to the families Calceolariaceae, Iridaceae and Solanaceae.
The family Calceolariaceae is composed of three genera, namely Calceolaria , Jovellana , and Porodittia . Calceolaria is the most successful oil-producing genus present in the Neotropical realm, with 210 oil-producing species. [5] This genus is pollinated by Chalepogenus and Centris oil-collecting bees. These bees, distinguished by their varying sizes and foraging capabilities, visit oil-flowers of different sizes and shapes to collect oil, effectively ensuring pollination for Calceolaria. [2] [8] [11]
Chalepogenus oil-collecting forage on Calceolaria flowers of small size, with a wide lower lip. It has been speculated that both of these criteria enhance the bees' ability to land and manipulate the flowers. [8] [11] [12]
A single floral visit extends for a minimum of 30 seconds. Chalepogenus bees initiate their visit by landing on the labellum and search for the flower's opening. Once they have found it, the bees use their heads to push aside the hindmost part of the two anthers, thereby revealing the previously hidden frontal section that contains Calceolaria pollen. The bees become dorsally coated with this pollen during this process; in other words, they pollinate Calceolaria flowers nototribically. As they collect oil with their forelegs, the majority of their bodies remains hidden within the labellum, with only their hindlegs visible from outside. Upon completing their oil collection, the bees back out and ipsilaterally transfer the collected oil from forelegs, to middle legs, then to hindlegs. [2] [3] [5]
The family Iridaceae comprises seven subfamilies, and within the subfamily Iridoideae, there are five tribes. One of these tribes is the Sisyrinchieae, which consists of four genera exclusively found in the Americas: Olsynium , Sisyrinchium , Solenomelus , and Tapeinia . Among Neotropical Iridoideae, the genus Sisyrinchium is the most diverse. Many of its species produce floral oil, which attracts oil-collecting pollinators, such as Chalepogenus bees. [13]
The oil-collecting bees take approximately 1 to 3 seconds to exploit each flower. Upon landing on the perianth, they insert themselves deep into the flower by firmly grasping the horizontal part of the perianth with their middle and hindlegs. As a result, the undersides of the pollinators' head and thorax are in contact with the stamen and stylodia. By doing so, they perform sternotribic pollination, in which ventral regions of the bees become covered by pollen. Although movements of the oil-collecting forelegs may not be visible, it is evident that the bees manipulate the filament column of the flower and collect floral oil. [14]
Within the family Solanaceae, which includes 98 genera, Nierembergia is the sole genus that offers non-volatile oil as a floral reward to pollinators, which are oil-collecting bees primarily belonging to the genera Tapinotaspis , Centris, and Chalepogenus.Chalepogenus bee species exhibit distinctive foraging behaviours by actively collecting both oil and pollen, in contrast to Tapinotaspis and Centris bees, which exclusively collect floral oil. [1] [15]
During the oil collection process, the oil-collecting bees land on the corolla limb and circle around the central fertile column to collect oil using their forelegs. This results in nototribic pollination, which is the deposition of pollen on oil-collectors’ heads. [15] In contrast, when Chalepogenus bee species collect pollen, they climb to the top of the central fertile column, and secure their grip just below the anthers using their mandibles. In a vertical, bottom-up posture, the bees collect pollen with their forelegs, and transfer it to the scopas located on their hindlegs. This specific positioning above the floral fertile parts leads to sternotribic pollination, which is characterised by the deposition of pollen from the anthers onto various ventral body regions of the pollinator, including the abdomen and legs. Therefore, by exhibiting both nototribic and sternotribic pollination, Chalepogenus bee species enhance the probability of effective pollination for Nierembergia species. [15]
In the Neotropical realm, there are three tribes of oil-collecting bees, namely Tapinotaspidini, Centridini, and Tetrapediini. The genus Chalepogenus belongs to the tribe Tapinotaspidini and is composed of 21 species: [3]
A pollinator is an animal that moves pollen from the male anther of a flower to the female stigma of a flower. This helps to bring about fertilization of the ovules in the flower by the male gametes from the pollen grains.
Pollination is the transfer of pollen from an anther of a plant to the stigma of a plant, later enabling fertilisation and the production of seeds, most often by an animal or by wind. Pollinating agents can be animals such as insects, for example beetles or butterflies; birds, and bats; water; wind; and even plants themselves. Pollinating animals travel from plant to plant carrying pollen on their bodies in a vital interaction that allows the transfer of genetic material critical to the reproductive system of most flowering plants. When self-pollination occurs within a closed flower. Pollination often occurs within a species. When pollination occurs between species, it can produce hybrid offspring in nature and in plant breeding work.
The genus Centris contains circa 250 species of large apid bees occurring in the Neotropical and Nearctic realms, from Kansas to Argentina. Most females of these bees possess adaptations for carrying floral oils rather than pollen or nectar. They mainly visit plants of the family Malpighiaceae to collect oil, but also visit others such as Plantaginaceae, Calceolariaceae, and Krameriaceae. Recent studies have shown they are sister to the corbiculate bees, the most well-known and economically important group of bees
Iridaceae is a family of plants in order Asparagales, taking its name from the irises. It has a nearly global distribution, with 69 accepted genera with a total of c. 2500 species. It includes a number of economically important cultivated plants, such as species of Freesia, Gladiolus, and Crocus, as well as the crop saffron.
Pseudocopulation describes behaviors similar to copulation that serve a reproductive function for one or both participants but do not involve actual sexual union between the individuals. It is most generally applied to a pollinator attempting to copulate with a flower. Some flowers mimic a potential female mate visually, but the key stimuli are often chemical and tactile. This form of mimicry in plants is called Pouyannian mimicry.
Nectar is a sugar-rich liquid produced by plants in glands called nectaries or nectarines, either within the flowers with which it attracts pollinating animals, or by extrafloral nectaries, which provide a nutrient source to animal mutualists, which in turn provide herbivore protection. Common nectar-consuming pollinators include mosquitoes, hoverflies, wasps, bees, butterflies and moths, hummingbirds, honeyeaters and bats. Nectar plays a crucial role in the foraging economics and evolution of nectar-eating species; for example, nectar foraging behavior is largely responsible for the divergent evolution of the African honey bee, A. m. scutellata and the western honey bee.
Hylaeus is a large and diverse cosmopolitan genus within the bee family Colletidae. This genus is also known as the yellow-faced bees or masked bees. This genus is the only truly globally distributed colletid, occurring on all continents except Antarctica.
Ornithophily or bird pollination is the pollination of flowering plants by birds. This sometimes coevolutionary association is derived from insect pollination (entomophily) and is particularly well developed in some parts of the world, especially in the tropics, Southern Africa, and on some island chains. The association involves several distinctive plant adaptations forming a "pollination syndrome". The plants typically have colourful, often red, flowers with long tubular structures holding ample nectar and orientations of the stamen and stigma that ensure contact with the pollinator. Birds involved in ornithophily tend to be specialist nectarivores with brushy tongues and long bills, that are either capable of hovering flight or light enough to perch on the flower structures.
In zoology, a palynivore /pəˈlɪnəvɔːɹ/, meaning "pollen eater" is an herbivorous animal which selectively eats the nutrient-rich pollen produced by angiosperms and gymnosperms. Most true palynivores are insects or mites. The category in its strictest application includes most bees, and a few kinds of wasps, as pollen is often the only solid food consumed by all life stages in these insects. However, the category can be extended to include more diverse species. For example, palynivorous mites and thrips typically feed on the liquid content of the pollen grains without actually consuming the exine, or the solid portion of the grain. Additionally, the list is expanded greatly if one takes into consideration species where either the larval or adult stage feeds on pollen, but not both. There are other wasps which are in this category, as well as many beetles, flies, butterflies, and moths. One such example of a bee species that only consumes pollen in its larval stage is the Apis mellifera carnica. There is a vast array of insects that will feed opportunistically on pollen, as will various birds, orb-weaving spiders and other nectarivores.
Pollination syndromes are suites of flower traits that have evolved in response to natural selection imposed by different pollen vectors, which can be abiotic or biotic, such as birds, bees, flies, and so forth through a process called pollinator-mediated selection. These traits include flower shape, size, colour, odour, reward type and amount, nectar composition, timing of flowering, etc. For example, tubular red flowers with copious nectar often attract birds; foul smelling flowers attract carrion flies or beetles, etc.
Nectar robbing is a foraging behavior used by some organisms that feed on floral nectar, carried out by feeding from holes bitten in flowers, rather than by entering through the flowers' natural openings. "Nectar robbers" usually feed in this way, avoiding contact with the floral reproductive structures, and therefore do not facilitate plant reproduction via pollination. Because many species that act as pollinators also act as nectar robbers, nectar robbing is considered to be a form of exploitation of plant-pollinator mutualism. While there is variation in the dependency on nectar for robber species, most species rob facultatively.
Calceolaria uniflora is a perennial plant of the genus Calceolaria, known as the slipperworts. It is originally from Tierra del Fuego in the southern part of South America.
Bombylius major is a parasitic bee mimic fly. B. major is the most common type of fly within the Bombylius genus. The fly derives its name from its close resemblance to bumblebees and are often mistaken for them.
Bombus hortorum, the garden bumblebee or small garden bumblebee, is a species of bumblebee found in most of Europe north to 70°N, as well as parts of Asia and New Zealand. It is distinguished from most other bumblebees by its long tongue used for feeding on pollen in deep-flowered plants. Accordingly, this bumblebee mainly visits flowers with deep corollae, such as deadnettles, ground ivy, vetches, clovers, comfrey, foxglove, and thistles. They have a good visual memory, which aids them in navigating the territory close to their habitat and seeking out food sources.
Flower constancy or pollinator constancy is the tendency of individual pollinators to exclusively visit certain flower species or morphs within a species, bypassing other available flower species that could potentially contain more nectar. This type of foraging behavior puts selective pressures on floral traits in a process called pollinator-mediated selection. Flower constancy is different from other types of insect specialization such as innate preferences for certain colors or flower types, or the tendency of pollinators to visit the most rewarding and abundant flowers.
The 'Tapinotaspidini' are a tribe of apid bees. They belong to the order Hymenoptera and the family Apidae. The Tapinotaspidini tribe consists of 180 different species. Many species of Apidae are recognised as oil-collecting bees and Tapinotaspidini possess this oil-collecting behaviour. It is maintained that mutualism exists between oil secreting flowers and oil collecting Tapinotaspidini bees. Morphological and molecular phylogenies have found that the trait of oil-collecting is polyphyletic. Tapinotaspidini are solitary bees which collect oil sources from flowers belonging to the families of Malpighiaceae, Solanaceae, Orchidaceae, Calceolariaceae, Iridaceae, Plantaginaceae, Melastomataceae and Krameriaceae. Tapinotaspidini species differ in terms of being generalist and specialist oil-collectors. Selected species exclusively obtain floral oil from one family of flowering plants, whilst many Tapinotaspidini species employ a range of plant families to fulfil their oil-collecting behaviour.
Macropis nuda is a ground nesting, univoltine bee native to northern parts of North America. Thus, this species cocoons as pupae and hibernates over the winter. The species is unusual as it is an oligolectic bee, foraging exclusively for floral oils and pollen from Primulaceae of the species Lysimachia ciliata.
The monocots are one of the two major groups of flowering plants, the other being the dicots. In order to reproduce they utilize various strategies such as employing forms of asexual reproduction, restricting which individuals they are sexually compatible with, or influencing how they are pollinated. Nearly all reproductive strategies that evolved in the dicots have independently evolved in monocots as well. Despite these similarities and their close relatedness, monocots and dicots have distinct traits in their reproductive biologies.
Pollen theft, also known as pollen robbery or floral larceny, occurs when an animal actively eats or collects pollen from a plant species but provides little or no pollination in return. Pollen theft was named as a concept at least as early as the 1980, and examples have been documented well before that. For example, native honey bees were documented 'stealing' large amounts of pollen from the large, bat-pollinated flowers of Parkia clappertoniana in Ghana in the 1950s. Nevertheless, pollen theft has typically received far less research attention than nectar robbing, despite the more direct consequences on plant reproduction.
An elaiophore is a plant organ that secretes oil.