Bombus vestalis

Last updated

Vestal cuckoo bumblebee
Bumblebee January 2008-4.jpg
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Apidae
Genus: Bombus
Species:
B. vestalis
Binomial name
Bombus vestalis
Geoffroy, 1785 [1]

Bombus vestalis, the vestal cuckoo bumblebee, is a species of cuckoo bumblebee that lives in most of Europe, as well as North Africa and western Asia. [2] It is a brood parasite that takes over the nests of other bee species. Its primary host is Bombus terrestris (the buff-tailed bumblebee). After its initial classification as Psithyrus vestalis, this bumblebee recently was reclassified into the genus Bombus, subgenus Psithyrus. [3]

Contents

Description

The queen is a large bumblebee with a length up to 21 mm (0.83 in) and a wingspan of 37 mm (1.5 in); [4] the male is considerably smaller (16 mm (0.63 in)). The bumblebee is predominantly black, with an orange collar. The third tergite has a border of yellow hairs, and the hairs on the fifth tergite are mostly white. The males are similar to the females, but smaller and with longer antennae. [5]

It is similar in appearance to another cuckoo bumblebee, Bombus bohemicus , but is distinguishable by either the length of the antennal segments or dissection and comparison of the genitalia. In Bombus vestalis, the fifth antennal segment will be the same length as the third and fourth together. [6]

A key characteristic of Bombus vestalis is the lack of corbiculae or a pollen basket on the hind legs of the bee. [3] [7] [8] [9] [10] [11] This is evolutionarily relevant because Bombus vestalis does not make its own nests or collect its own resources. With its larger body and poor foraging skills, the female Bombus vestalis are adapted to taking over nests of other species which have already been made and using the workers in these colonies to collect pollen.

Sex

A brood of bees successfully raised by Bombus vestalis is mainly female. [8] This is evolutionarily beneficial since the female is the sex which takes over host species and allows Bombus vestalis to reproduce. In fact, many of the male bees which are hatched in a nest that has been taken over by Bombus vestalis are a result of host workers who were able to successfully lay eggs despite the aggression of the invaders. Although they display haplodiploidy where males are haploid and females are diploid, [9] morphologically, male and female Bombus vestalis are very similar and can be classified with a mosaic gynander. They have similar mandible and body structures, and it is likely that the differences are only derived from chromosomal alterations during development of the embryo. [12]

Taxonomy and phylogeny

Bombus vestalis is part of the family Apidae. Until recently, it used to be identified as Psithryus vestalis. It was then renamed under the genus Bombus and classified as subgenus Psithyrus. The subgenus Psithyrus refers to a variety of cuckoo bumblebees who have no worker caste and reproduce by taking over host colonies and using workers of those colonies to rear their young. [3] They can be confused with the bee Bombus bohemicus since both are found in similar regions and are parasitic in behavior. However, Bombus bohemicus is more intense in color and is a generalist parasite when choosing its host. [7]

Distribution

The bumblebee is common from North Africa in the south to southern Sweden in the north, and from Ireland in the west to northern Iran in the east. [2] It is common throughout England and Wales, but has only been sighted in Scotland since 2009. [5] Using data from the National Biodiversity Network gateway, Bombus vestalis is most prominent in south-east England. [13]

In Ireland the bee was believed to be all but extinct in the 20th century with the last recorded sighting in 1926 in Carlow. However, in 2014 a population was rediscovered in the walled garden at Saint Enda's Park in Rathfarnham. [14]

Ecology

Bombus vestalis is a cuckoo bumblebee; it does not construct any nest of its own, but usurps the nest of Bombus terrestris , kills the host queen, and forces the host workers to raise its offspring. [4] The male bumblebees often congregate in gardens in the suburbs. [15]

The queen emerges early in the spring; the males emerge later, in late May to early June. Its food sources are flowering plants such as clover (males especially often visit white clover), tufted vetch, knapweed, and others. In the spring, the emerging queens frequently fly to flowers such as deadnettles, sallows, blackthorns, and dandelions. [4]

Life cycle

The life cycle of Bombus vestalis is dependent on its host B. terrestris, who begin the growth of their colony in the early spring, slowly building up the nest. [9] The female Bombus vestalis hibernates until April, after the host has raised a first generation of workers. [3] [7] [11] At this point, the nest is an ideal size for the female B. vestalis to take over. In taking over the nest, the invaders assert their dominance among the workers bees for the first few days without killing the queen. It takes nearly a month for B. vestalis to fully take over the nest and raise her brood. [8]

Behavior

Mating behavior

Male Bombus vestalis have been found to be attracted to floral odors, particularly the polar compounds of Ophrys flowers, which mimic the sex pheromones of virgin females. In short, olfactory cues play an essential role to attract males, for virgin female Bombus vestalis, and their sexually deceptive orchid mimics, O. chestermanii and O. normanii. For these orchid mimics, the males are attracted to their floral cues, which leads to the male attempting to copulate with the orchid labellum, during which the flower is pollinated. [16]

Single host parasitism

Under the subgenus Psithyrus, there are two types of parasitic bees; one type of bee is non-specific when choosing its host and the other (e.g., B. vestalis) chooses an exclusive host. These two different behaviors are likely to have developed because of a chemical difference in pheromones. Socially parasitic bees have been shown to identify their hosts through pheromone trails left by host workers while they are collecting pollen. [7] By following these natural footprints, a parasitic bee can find the entrance to the hive of its desired host. Experiments show that B. vestalis is attracted to a specific combination of both nonpolar and polar pheromones, a combination that is specific to B. terrestris. [7] Though the latter can be parasitized by other bees, B. vestalis will not take over the nests of any other species. It can also distinguish the odors of differently aged host workers, thus determining which workers to attack when invading a nest. [7]

Identifying colony size

The success of Bombus vestalis is dependent on the size of the nest which it invades. As soon as a female enters a colony, she is investigated by the workers and often faces attacks from them. [8] Larger colonies will have more workers who are capable of defending the nest. Thus a female B. vestalis must weigh the costs of parasitizing a nest when the colony is very large. [11] Experiments have been done to reproduce this scenario. However, B. vestalis cannot take over a nest which is too small. During an invasion of a small nest, though successful, too many host workers will die and there will be a shortage of workers to take care of the invading queen and her eggs. Before attacking a colony, the female must accurately judge the size of the nest, through the frequency and size of workers moving in and out, and the pheromones of these workers before attempting an attack. [11]

Identifying colony age

In experiments with B. vestalis and its host B. terrestris, an interesting phenomenon has been observed. Any host workers born after the invasion of a female B. vestalis were unharmed despite the takeover of the queen. Similarly, newborn B. terrestris were not attacked during the invasion. [8] A female B. vestalis will only target older host worker bees who are a threat to her and her eggs. [11] She is able to identify these workers through the detection of pheromones. The older a terrestris worker is, the more pheromones it secretes. [11] Since B. vestalis is so perceptive of these odors, she knows which worker bees to kill so that the brood of eggs is safely and solely her own. The remaining younger Bombus terrestris and those born soon after takeover of the queen are available to help care for the new B. vestalis nest.

Mauling

Many parasitic bees use mimicry to introduce themselves into the nests of their hosts. [11] They mimic the odor of the host and oftentimes live in cooperation with the host species when raising their eggs. This is more common in larger colonies. Bombus vestalis is unique in that it has a mauling behavior. [11] With a smaller colony to take over, the female B. vestalis can individually kill off the workers in the B. terrestris nest. When it comes to the queen, she may simply push her off the nest. [8] This behavior is evolutionarily possible because Bombus terrestris nests are not too large and because Bombus vestalis invades early in the season. It will then suppress ovarian development of the remaining workers. [10]

See also

Related Research Articles

<span class="mw-page-title-main">Bumblebee</span> Genus of insect

A bumblebee is any of over 250 species in the genus Bombus, part of Apidae, one of the bee families. This genus is the only extant group in the tribe Bombini, though a few extinct related genera are known from fossils. They are found primarily in higher altitudes or latitudes in the Northern Hemisphere, although they are also found in South America, where a few lowland tropical species have been identified. European bumblebees have also been introduced to New Zealand and Tasmania. Female bumblebees can sting repeatedly, but generally ignore humans and other animals.

<i>Bombus terrestris</i> Species of bee

Bombus terrestris, the buff-tailed bumblebee or large earth bumblebee, is one of the most numerous bumblebee species in Europe. It is one of the main species used in greenhouse pollination, and so can be found in many countries and areas where it is not native, such as Tasmania. Moreover, it is a eusocial insect with an overlap of generations, a division of labour, and cooperative brood care. The queen is monandrous which means she mates with only one male. B. terrestris workers learn flower colours and forage efficiently.

<span class="mw-page-title-main">Cuckoo bee</span> Kleptoparasitic bee lineages

The term cuckoo bee is used for a variety of different bee lineages which have evolved the kleptoparasitic behaviour of laying their eggs in the nests of other bees, reminiscent of the behavior of cuckoo birds. The name is perhaps best applied to the apid subfamily Nomadinae, but is commonly used in Europe to mean bumblebees Bombus subgenus Psithyrus. Females of cuckoo bees are easy to recognize in almost all cases, as they lack pollen-collecting structures and do not construct their own nests. They often have reduced body hair, abnormally thick and/or heavily sculptured exoskeleton, and saber-like mandibles, although this is not universally true; other less visible changes are also common.

An obligate parasite or holoparasite is a parasitic organism that cannot complete its life-cycle without exploiting a suitable host. If an obligate parasite cannot obtain a host it will fail to reproduce. This is opposed to a facultative parasite, which can act as a parasite but does not rely on its host to continue its life-cycle. Obligate parasites have evolved a variety of parasitic strategies to exploit their hosts. Holoparasites and some hemiparasites are obligate.

<i>Psithyrus</i> Subgenus of bees

Cuckoo bumblebees are members of the subgenus Psithyrus in the bumblebee genus Bombus. Until recently, the 28 species of Psithyrus were considered to constitute a separate genus. They are a specialized socially parasitic lineage which parasitises the nests of 'true' bumblebees, resulting in the loss of the ability to collect pollen and establish their own nests. Cuckoo bumblebees do not create a worker caste and produce only male and female reproductives. They are considered inquilines in the colonies of 'true' bumblebees.

<span class="mw-page-title-main">Early bumblebee</span> Species of bee

The early bumblebee or early-nesting bumblebee is a small bumblebee with a wide distribution in most of Europe and parts of Asia. It is very commonly found in the UK and emerges to begin its colony cycle as soon as February which is earlier than most other species, hence its common name. There is even some evidence that the early bumblebee may be able to go through two colony cycles in a year. Like other bumblebees, Bombus pratorum lives in colonies with queen and worker castes. Bombus pratorum queens use aggressive behavior rather than pheromones to maintain dominance over the workers.

<i>Bombus hypnorum</i> Species of bee

The tree bumblebee or new garden bumblebee is a species of bumblebee common in the European continent and parts of Asia. Since the start of the twenty-first century, it has spread to Great Britain. These bumblebees prefer habitats that others do not, allowing them to pollinate flowers in areas that many other species do not get to.

<i>Bombus lapidarius</i> Species of bee

Bombus lapidarius is a species of bumblebee in the subgenus Melanobombus. Commonly known as the red-tailed bumblebee, B. lapidarius can be found throughout much of Central Europe. Known for its distinctive black and red body, this social bee is important in pollination.

<i>Bombus hyperboreus</i> Species of bee

Bombus hyperboreus is a species of Arctic bumblebee with a circumpolar distribution. The species is primarily found in the arctic areas of Greenland, northern Scandinavia, and Russia. In 2015 the nearctic species, Bombus natvigi, was separated from this species, based on genetic analysis. Accordingly, Bombus hyperboreus is limited to the Palaearctic, despite older literature listing this species as occurring in the Nearctic.

<i>Bombus barbutellus</i> Species of bee

Bombus barbutellus, or Barbut's cuckoo-bee, is a species of cuckoo bumblebee, widespread, if not especially common, in most of Europe.

<i>Bombus citrinus</i> Species of bee

Bombus citrinus is a species of bumblebee known commonly as the lemon cuckoo bumblebee due to its lemon-yellow color. It is native to eastern North America.

<i>Bombus sylvestris</i> Species of bee

Bombus sylvestris, known as the forest cuckoo bumblebee or four-coloured cuckoo bee, is a species of cuckoo bumblebee, found in most of Europe and Russia. Its main hosts are Bombus pratorum, Bombus jonellus, and Bombus monticola. As a cuckoo bumblebee, Bombus sylvestris lays its eggs in another bumblebee's nest. This type of bee leaves their young to the workers of another nest for rearing, allowing cuckoo bumblebees to invest minimal energy and resources in their young while still keeping the survival of their young intact.

<i>Bombus bohemicus</i> Species of bee

Bombus bohemicus, also known as the gypsy's cuckoo bumblebee, is a species of socially parasitic cuckoo bumblebee found in most of Europe with the exception of the southern Iberian Peninsula and Iceland. B. bohemicus practices inquilinism, or brood parasitism, of other bumblebee species. B. bohemicus is a generalist parasite, successfully invading several species from genus Bombus. The invading queen mimics the host nest's chemical signals, allowing her to assume a reproductively dominant role as well as manipulation of host worker fertility and behavior.

<i>Bombus suckleyi</i> Species of bee

Bombus suckleyi is a species of bumblebee known commonly as Suckley's cuckoo bumblebee, named after biologist George Suckley. Suckley's bumble bee is a generalist pollinator and represents a rare group of obligate, parasitic bumble bees. Suckley's bumble bee is a social-parasite because it invades the nests of the host bumble bees, including the western bumble bee, and relies on host species workers to provision its larvae. It is native to northwestern North America, including Alaska and parts of western and central Canada and the western United States.

<i>Bombus lucorum</i> Species of bee

Bombus lucorum, the white-tailed bumblebee, is a species of bumblebee, widespread and common throughout Europe. This name has been widely used for a range of nearly identical-looking or cryptic species of bumblebees. In 1983, Scholl and Obrecht even coined the term Bombus lucorum complex to explain the three taxa that cannot be easily differentiated from one another by their appearances. A recent review of all of these species worldwide has helped to clarify its distribution in Europe and northern Asia, almost to the Pacific. B. lucorum reaches the Barents Sea in the North. However, in southern Europe, although found in Greece it is an upland species with its distribution never quite reaching the Mediterranean.

<i>Bombus pensylvanicus</i> Species of bee

Bombus pensylvanicus, the American bumblebee, is a threatened species of bumblebee native to North America. It occurs in eastern Canada, throughout much of the Eastern United States, and much of Mexico.

<i>Bombus occidentalis</i> Species of bee

Bombus occidentalis, the western bumblebee, is one of around 30 bumblebee species present in the western United States and western Canada. A recent review of all of its close relatives worldwide appears to have confirmed its status as a separate species.

<i>Bombus affinis</i> Species of bee

Bombus affinis, commonly known as the rusty patched bumble bee, is a species of bumblebee endemic to North America. Its historical range in North America has been throughout the east and upper Midwest of the United States, north to Ontario, Canada, where it is considered a "species at risk", east to Quebec, south to Georgia, and west to the Dakotas. Its numbers have declined in 87% of its historical habitat range. On January 10, 2017, the United States Fish and Wildlife Service placed B. affinis on the list of endangered species, making the rusty patched bumblebee the first bee to be added to the list in the continental United States.

<i>Bombus terricola</i> Species of bee

Bombus terricola, the yellow-banded bumblebee, is a species of bee in the genus Bombus. It is native to southern Canada and the east and midwest of the United States. It possesses complex behavioral traits, such as the ability to adapt to a queenless nest, choose which flower to visit, and regulate its temperature to fly during cold weather. It was at one time a common species, but has declined in numbers since the late 1990s, likely due to urban development and parasite infection. It is a good pollinator of wild flowers and crops such as alfalfa, potatoes, raspberries, and cranberries.

<span class="mw-page-title-main">Nest usurpation</span>

Nest usurpation is when the queen of one species of eusocial insects takes over the colony of another species.

References

  1. ITIS Report
  2. 1 2 Pierre Rasmont. "Bombus (Psithyrus) vestalis (Fourcroy, 1785)". Université de Mons. Retrieved 5 January 2013.
  3. 1 2 3 4 Carvell, Claire; Rothery, Peter; Pywell, Richard F.; Heard, Matthew S. (2008-06-01). "Effects of resource availability and social parasite invasion on field colonies of Bombus terrestris". Ecological Entomology. 33 (3): 321–327. doi:10.1111/j.1365-2311.2007.00961.x. ISSN   1365-2311.
  4. 1 2 3 Benton, Ted (2006). "Chapter 9: The British Species". Bumblebees. London, UK: HarperCollins Publishers. pp. 403–406. ISBN   978-0007174515.
  5. 1 2 "Cuckoo bumblebees". Bumblebee.org. Retrieved 5 January 2013.
  6. Vestal Cuckoo Bumblebee - Bombus vestalis NatureSpot
  7. 1 2 3 4 5 6 Kreuter, Kirsten; Twele, Robert; Francke, Wittko; Ayasse, Manfred (2010-08-01). "Specialist Bombus vestalis and generalist Bombus bohemicus use different odour cues to find their host Bombus terrestris". Animal Behaviour. 80 (2): 297–302. doi:10.1016/j.anbehav.2010.05.010.
  8. 1 2 3 4 5 6 Van Honk, Cor; Roseler, Peter-Frank; velthuis, Hayo; Malotaux, Marieke (1981). "The Conquest of a Bombus Terrestris Colony by a Psithyrus Vestalis Female". Apidologie. 12: 57–67. doi: 10.1051/apido:19810105 . Retrieved 26 September 2015.
  9. 1 2 3 Erler, S; Lattorff, H. M. G. (22 September 2010). "The degree of parasitism of the bumblebee (Bombus terrestris) by cuckoo bumblebees (Bombus (Psithyrus) vestalis)". Insectes Sociaux. 57 (4): 371–377. doi:10.1007/s00040-010-0093-2 . Retrieved 26 September 2015.
  10. 1 2 Vergara, Carlos; Schoder, Stefan; Almanza, Maria; Wittmann, Dieter (1 January 2003). "Suppression of ovarian development of Bombus terrestris workers by B. terrestris queens, Psithyrus vestalis and Psithyrus bohemicus females". Apidologie. 34 (6): 563–568. doi: 10.1051/apido:2003056 . Retrieved 26 September 2015.
  11. 1 2 3 4 5 6 7 8 Sramkova, A.; Ayasse, M. (2009-03-03). "Chemical ecology involved in invasion success of the cuckoo bumblebee Psithyrus vestalis and in survival of workers of its host Bombus terrestris". Chemoecology. 19 (1): 55–62. doi:10.1007/s00049-009-0009-7. ISSN   0937-7409.
  12. Michez, Denis; Rasmont, Pierre; Terzo, Michaël; Vereecken, Nicolas J. (2009-01-01). "A synthesis of gynandromorphy among wild bees (Hymenoptera: Apoidea), with an annotated description of several new cases" (PDF). Annales de la Société Entomologique de France. New Series. 45 (3): 365–375. doi:10.1080/00379271.2009.10697621. ISSN   0037-9271.
  13. Grid map of records for Bombus (Psithyrus) vestalis National Biodiversity Network
  14. "Rare bumblebee rediscovered in Ireland after 88 years".
  15. "Bombus". Natural History Museum, London, UK. 2013. Retrieved 5 January 2013.
  16. Gögler, J.; Twele, R.; Francke, W.; Ayasse, M (2011). "Two phylogenetically distinct species of sexually deceptive orchids mimic the sex pheromone of their single common pollinator, the cuckoo bumblebee Bombus vestalis". Chemoecology. 21 (4): 243–252. doi:10.1007/s00049-011-0085-3.

Commons-logo.svg Media related to Bombus vestalis at Wikimedia Commons