HOMES AND GARDENS - BEES (Apidae)





 

 

Bumblebees are common visitors to gardens containing nectar- and pollen-bearing flowers, be it in borders, greenhouses or orchards. They also nest in gardens, usually larger ones but not necessarily – walls, bare earth and hedge margins all offer prospects.

The group is vital for the process of pollinating everything from apples to runner beans and tomatoes, and hence deserves every encouragement, especially as a number of species are under pressure across the country. They also merit attention as one of the most striking, attractive and useful (in human terms) invertebrates we see, which means they have immense potential for imbuing youngsters with enthusiasm for nature.

Unlike birds, butterflies and dragonflies, there is no consistency in English namings for bumblebees nationwide, so the scientific name is best applied. Two of the commonest visitors are Bombus terrestris (Buff-tailed Bumblebee, 22mm) and Bombus lapidarius (Red-tailed Bumblebee, 20mm) shown above nesting in the ground. Sadly like many nests in such a location this one was dug up by Badgers. Other regulars are Bombus hortorum (Garden Bumblebee, 20mm), Bombus pratorum (Early Bumblebee, 16mm), Bombus pascuorum (Common Carder Bee, 20mm) and Bombus lucorum (White-tailed Bumblebee, 23mm).

Bombus terrestris can vary in colour, with the ‘tail’ covering all hues between whitish and red-orange, and together with Bombus pratorum is one of the first bumblebees seen each year. Nests of this species and of Bombus lucorum can be large, with up to 300 workers in the former and 200 in the latter. Both are always made under cover of some sort. The tongues of both species are too short to gather nectar from long-tubed flowers but they can cut their way in to achieve the desired objective.

The various cuckoo bees from this family which take over bumblebee nests, killing the queen, are often easily seen in gardens, especially in flower and nectar-filled borders. They have no need of pollen. Bombus vestalis (20mm) is one of the commonest in southern England and uses Bombus terrestris as the host.

Certain species of British bumblebee are in decline or facing problems, including Bombus ruderarius, Bombus sylvarum and Bombus ruderatus, so the arrival of the newcomer Bombus hypnorum (Tree Bumblebee, 20mm) from Europe is welcome. They are easily distinguished from our other bumblebees because uniquely they have an orange thorax and white tail.

The first colonist was found here in 2001 near Southampton and Bombus hypnorum was identified sporadically in the following years, including at Kew Gardens as well as a disused sandpit 50 metres from my Reigate garden in 2007. The pace of colonisation is pretty rapid northwards and westwards and there is no reason on the face of it why this bumblebee shouldn’t end up being found in most of Britain.

Bombus hypnorum is suited by open woodland, and that is effectively what gardens amount to in many instances. They have been turning up increasingly in that setting and in 2011 there were significant numbers on Cotoneaster flowers. Nesting occurs in aerial cavities, sometimes on buildings and often old bird boxes are ‘recycled’. Colonies are fairly large and, unlike a number of other fauna and flora colonists, this species poses no threat to native wildlife.

Some mining bees nest in gardens and many more visit well-stocked borders to take nectar or gather pollen. These are often not noticed since many are small, with a huge variety. One of these is the little Andrena labiata (8mm), a nationally scarce species which is able to take pollen from a wide variety of plants including in gardens Cotoneaster, Star of Bethlehem and Rock Rose cultivars. With such a range of pollen sources it will be no surprise to see this species expand in numbers over the next few years, a comment which may also apply to its very rare and even smaller cleptoparasite Nomada guttulata (6mm).

Other solitary bees are larger and much brighter in colouration, particularly when they emerge as adults looking fresh as paint before the natural wear and tear of a busy life on the surface take their toll. The mining bee Andrena nitida (14mm) is a case in point. This common species is seen from April to June nesting in grassland of all kinds (including lawns) and collecting pollen on various plants such as Dandelion (Taraxacum officinale). The pictured female, with jet black abdomen and lovely reddish thorax, is clearly only just ‘out’. The same applies to the female Andrena nigroaenea (14mm) pictured on Garden Star-of-Bethlehem. Lasioglossum bee species generally are smaller and less brightly coloured but a number have an appealing bronzy or greenish shading, such as Lasioglossum smeathmanellum (8mm).

Andrena nitida is one of the host species of the handsome cuckoo bee Nomada goodeniana (11mm), which can be seen from April through to August. Even more striking than Andrena nitida is the female Andrena fulva (13mm) with her bright red thorax and slightly paler abdomen. This is a relatively common species from March to June, and may be found nesting in lawns in decent aggregations providing there is some bare ground, often on the margins. The male, in contrast, has more subdued though still impressive colouring.

In the spring of 2005 I photographed a female Andrena fulva and a couple of days later on May 5 a female of the cuckoo bee Nomada signata, which parasitises the nests of that species, turned up. Nomada signata (10mm), which has beautiful colouring, is rare, to the extent of being designated a Red Data Book 2 species, and has not been seen in more than a handful of places since 1990.

Nothing ventured, nothing gained, I did some work on the lawn in the vicinity of where both bees had been sighted, in the hope of encouraging more Andrena fulva to nest. In 2006 there were at least 13 nests in an area of five square metres, and on a warm day (May 4) two Nomada signata females turned up to take advantage. The action came after 5pm, both times within 15 minutes of the host leaving the burrow. The same thing, at the same time, occurred with one female on May 5. In the warmer spring of 2007 a female appeared in mid-April but sadly, and for no treason, there was no sign of Andrena fulva or the parasite in 2009, 2010 or 2011.

Another cuckoo bee which is less species specific in its requirements is the tiny Nomada flavoguttata (6mm), seen from March to August. The pictured female was searching in the lawn but it is a common species in more open areas including the heathland nearby.

Osmia caerulescens, the Blue Carpenter Bee (10mm), is around from April to July and can be found in gardens nesting in wood, stems and sometimes mortar, but is nothing like so common as the Red Mason Bee (Osmia bicornis, 12mm). Both these species and Osmia leaiana (10mm), are dealt with in detail in the Insect Boxes page of this section. However, it is worth noting here that Osmia caerulescens and Osmia leaiana have significant dimorphism in colouring between the sexes.

Osmia bicornis can be a nuisance to householders when nesting in mortar and the same applies to Anthophora plumipes (14mm). This species takes advantage of house walls as well as vertical banks of soil of varying kinds and is one of a group of superbly effective hovering bees regularly seen in gardens. The pictured Anthophora plumipes female was nesting in a large wall on the side of a cottage not far from Burford and with around 15 at work in the location this offered an interesting test case.

Even without regular visits by the pollen-clad females, the nests were easily spotted. Up to five of the bee’s cleptoparasite Melecta albifrons (13mm, and not so chunky) were visible at any one time on the wall waiting for the host to go pollen gathering. Once inside, none of the intruders showed any urgency and twice they were still on the premises when the Anthophora plumipes returned.

Predictably, the resident tried to eject the invader but seemingly this proved difficult since there was considerable buzzing inside for about two minutes. The bees then appeared, covered in mortar grains, with Anthophora plumipes holding the parasite by a leg.

The Melecta albifrons was shooed away but did not travel very far and settled down to wait for another chance. Understandably, the Anthophora plumipes did not use her sting as this would be fatal and destroy her chances of breeding successfully. Mind you, this bee’s chances of success probably had already been totally compromised, and her nest was visited at least once more while I was watching.

The male Anthophora plumipes is strikingly marked, especially round the face, and is another example of sexual dimorphism, being much harder to reconcile with the female in appearance than many bee species. It is exactly the same with Anthophora furcata (12mm), which exceptionally among the genus nests in decayed wood. This is a later species, emerging in June, and consequently is even more likely to be seen hovering above garden flowers for nectar.

To some extent these males resemble another species found in gardens on occasions, Anthidium manicatum or Wool Carder Bee. At 15mm the male is larger than the female, a rare status in bees, and they can be aggressive in protecting nectaring/mating areas to the point of killing intruding invertebrates on occasions. That is extremely rare if not unique among our bee fauna.

The species, which is fairly common and most easily seen in June and July, is found in various habitats besides gardens, such as woodland, downland and coastal dunes. Nests, which are lined with hairs gathered from plants, occur in existing cavities in plants, dead wood, soil and masonry.

Even a species as large and aggressive as Anthidium manicatum has a cleptoparasite. This is Stelis punctulatissima, which at 10mm or so is the largest and most robust of the Stelis genus of cuckoo bees in Britain. Stelis punctulatissima also parasitises two other types of Megachilid bee including Osmia aurulenta. Officially a nationally scarce species, it appears to be getting scarcer.

The results of the activities of leaf-cutter bees (Megachile spp) are seen quite frequently since using the jaws, they cut neat sections of leaf from various plants, including Roses, and carry these off slung underneath to fill the nest. Pollen is carried on hairs beneath the abdomen rather than on the legs as with most bee species. The nests can be in pre-existing cavities in almost any setting, or burrowed into soil.

There are seven species of Megachile bees in Britain and four are seen every year in the garden, notably gathering pollen but also nesting in mortar or wood. Megachile centuncularis (10mm) has always been a pretty common species seen from June to August but it has been undergoing something of a decline lately, for no apparent reason. They usually construct their nests in wood but the pictured female with part of a leaf she has just cut built her nest in brickwork. Megachile versicolor is similar in size and behaviour but the pollen brush is black at the apex rather than entirely orange.

Megachile willughbiella (up to 17mm) is much larger, and besides dead wood and soil this species has been found nesting in a length of rubber hose. They make a formidable sight in flight with their size and dark colouring. Larger still is Megachile ligniseca, which is widely distributed in southern Britain but is generally uncommon. The female has pale golden pollen hairs underneath the abdomen, with black ones on the last two segments. They nest in holes in dead wood, fly from June to August and forage from many different plants.

Like all bees, the Megachilids have parasites preying on them, principally the Coelioxys genus which is rather elusive but does appear now and then. These are striking banded bees, with the female having an abdomen that tapers to a definite point as can be seen clearly on the accompanying image of Coelioxys elongata (to 15mm). Coelioxys females use this device to cut a slit in the host bee’s cell, through which an egg is laid. The very long curved jaws of the second instar larva are used to destroy the egg or young larva of the host bee. Later instars have normal jaws and feed on the host bee’s provisions.

Coelioxys bees are infrequently seen and never in numbers – two of the images on this page were taken in the garden, where Escallonia in bloom is a popular plant for the genus. Coelioxys elongata, the largest, is known to attack the nests of Megachile willughbiella. The same applies to Coelioxys rufescens (12mm) while Coelioxys inermis (12mm), one of the commonest nationally, goes for the the nests of Megachile centuncularis, Megachile versicolor and possibly Megachile ligniseca as well.

Images © Jeremy Early. All rights reserved.

In 2013 I published My Side of the Fence – the Natural History of a Surrey Garden. Details may be found, and orders placed, via this hyperlink My Side of the Fence. In November 2015 Surrey Wildlife Trust published the atlas Soldierflies, their allies and Conopidae of Surrey, jointly written by David Baldock and me. Details are on this web page: Atlas.

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