1 WNE 2019 18 Species Are Social Species. Remaining 6 Species Are
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Bumblebees There are currently 24 species of bumblebee resident in Britain and 250 worldwide Bumblebees evolved in the Himalayas around 35 million years ago, and all species are quite closely related. The old English name for a Bumblebee is a Dumbledore just in case you ever wondered where JK Rowling got the name Another, the Short-haired bumblebee (Bombus subterraneus), is currently being reintroduced after going extinct in 1988. Britain also has two extinct bumblebee species: Cullum’s bumblebee (Bombus cullumanus) last recorded on the Berkshire Downs in 1941, and the Apple bumblebee (Bombus pomorum), a short-lived establishment on the south coast in the mid-1800s. They are wild, form short-lived social colonies (typically up to 3 months) and construct their own nests in cavities in hedgerows, under rocks, in disused mouse or birds’ nests, or in cavity walls. Bumblebees have the longest tongue of all UK bees reaching just over 2 cm at full stretch. The old English name for a Bumblebee is a Dumbledore just in case you ever wondered where JK Rowling got the name Seven species of bumblebee (the ‘Big 7’) are widespread across most of Britain. These are: . Red-tailed (Bombus lapidarius) . Early (Bombus pratorum) . Common carder (Bombus pascuorum) . White-tailed (Bombus lucorum) . Buff-tailed (Bombus terrestris) . Garden (Bombus hortorum) . Tree (Bombus hypnorum) The Heath bumblebee (Bombus jonellus) sometimes joins the group above, to form a ‘Big 8’, although it is absent from much of the English Midlands. There are 8 bumblebee species listed on at least one of the English, Welsh and Scottish conservation priority species lists. Many of these are endemic species can be abundant in small areas. Others are more widespread, but at a very low population density. 18 species are social species. They make nests, collect pollen and have a worker caste. Remaining 6 species are Cuckoo bumblebees They have a parasitic lifestyle, taking over existing nests established by other species. They don’t have workers, just queens and males. They tend to be widespread but only at a comparatively low abundance. British bumblebees can be divided into three groups based on queen tail colour and their rarity status. 1 WNE 2019 Bumblebees have the longest tongue of all UK bees reaching just over 2 cm at full stretch Similar species There are many other flying insects which resemble bumblebees! Sometimes these are deliberate mimics (such as the hoverfly (Volucella bombylans)) exploiting their predator’s reluctance to take on something which could fight back. Some look similar because they are closely related to bumblebees eg.Hairy-footed flower bee (Anthophora plumipes)) Sometimes it’s just convergent evolution eg. Spring-flying parasitic fly (Tachina ursina)) where the traits that help bumblebees thrive (large size, bulky shape, hair, etc.) also favour the survival of other species. Usually, it is relatively easily to recognise the mimic species. Bumblebees are bigger, hairier and fly more deliberately with a lower-pitched buzz than most of the similar fly species. However, sometimes the mimics can be very similar to bumblebees, and short of examining a specimen the best way to separate the groups is to examine the heads. Bumblebees have long, multi-section tubular antennae, long tubular mouthparts (though these are often folded up), and relatively small eyes. 2 WNE 2019 Top tips for bumblebee ID Bumblebees can be very difficult to identify at first, although they are often relatively straightforward! There are 24 species in Britain, but with queens looking different to males (and sometimes to workers), as well as different colour forms for most species, there can be a bewildering array of different-looking bees. When, later in the year, sun-bleached and worn bees are prevalent, identification can be very tricky indeed! The first thing to be aware of is that only seven or eight bumblebee species are both widespread and abundant: these species are likely to make up around 95-99% of your bumblebee sightings. There are a further six species (the cuckoo bumblebees) which are parasitic in the nests of these common species and so are largely similarly widespread, but at a much lower abundance. The remaining 11 species tend to be localised or habitat-specific, and are correspondingly rarer, though they can be abundant where present. Generally, though, even when the rare species are present, the common species will still be more abundant and must be ruled out first. Consequently getting to grips with the Big Eight (Common carder, Red-tailed, Early, Tree, Garden, Heath, Bufftailed and White-tailed bumblebees) is the major step Bumblebees have a tendency to hide their distinguishing features by curling up – generally views of the face, tail, stripes and legs are all useful Step 1. Tail colour Bumblebees fall into three rough groups based on tail colour – white-tailed (includes off-white through to yellow), redtailed, and ‘uniform-tailed’ bees, where the tail is the same colour as the rest of the abdomen (usually ginger). This is the most important thing to start identifying your bumblebee. Step 2. Banding The next step is to look at the banding patterns, especially for the white-tailed species. A large number of bumblebees have the classic white-tail, black-and-yellow-bands look, but they vary from one to three thick yellow bands according to species. Buff-tailed bumblebee (left image) has two yellow bands, whereas Garden bumblebee (right image) has three yellow bands. Step 3. True or cuckoo bumblebee? 3 WNE 2019 Cuckoo bumblebees, like male ‘true’ bumblebees, have hairy hind legs with no pollen baskets, but they also have relatively dark wing membranes, a v-shaped or gently-scalloped edge to the top of the tail colouration, a small brush of black hairs at the end of the abdomen, and short faces (if your bee has a long face then it’s definitely not a cuckoo). Step 4. Caste Working out what caste (queen, worker or male) your bee is can sometimes be easier than getting it to species, and is always helpful in that process. Queens and workers are generally very similar to each other, with a couple of exceptions. Queen Buff-tailed bumblebees have an orangey-buff tail, whereas workers of the same species have white tails (and are thus often indistinguishable from worker White-tailed bumblebees). Additionally, worker Early bumblebees often lose the yellow abdominal band of the queen, looking much darker than their parent. Generally, male bumblebees have hairy hind legs without a pollen basket (though beware female cuckoo bees, which also have hairy hind legs). Males also usually have more facial hair than females (either queens or workers) – and in several species this is a bright, obvious yellow. Males also generally have longer, more straggly hair, so if your bee has hairy legs, a moustache, and looks slightly unkempt it’s probably a male. Early bumblebee males have yellow facial hair. Behaviour can be a useful tool to separate males from workers and queens: because males do not have to collect pollen for the nest, they tend to sit lazily on flowers. They may also be observed flying along hedgerows searching for a mate. They do not feed during this time, so will land briefly on a surface, and then fly off again. 4 WNE 2019 They often patrol the same area for a while, so you may see the same bee repeating the circuit over and over again. In contrast, females tend to be much busier, flying quickly from flower to flower, and rarely wasting time by resting on flowers. The time of year can also be helpful – males become common in late summer and autumn, whereas females are present throughout the whole lifecycle. Other features to watch out for… Some bumblebees also produce melanic individuals. These produce much larger quantities of a black pigment, melanin, than normal, and so look much darker. Some species produce entirely-black individuals (such as the Ruderal bumblebee), while others only produce partlymelanic bees (such as the Tree bumblebee, where the thorax is black but the white tail remains present). However, there are often the remnants of the ‘normal’ markings, though it may take a strong light to see them! Above all, identifying bumblebees takes patience. Identification sites: https://www.bumblebeeconservation.org/white-tailed-bumblebees/short-haired-bumblebee/ https://www.naturespot.org.uk/taxonomy/term/19396 https://www.bumblebeeconservation.org/identify-a-bumblebee/ Species Listed: ***SPECIES MOST LIKELY IN NORTH EAST LINCOLNSHIRE Social bumblebees ***Buff-tailed bumblebee (Bombus terrestris) ***White-tailed bumblebee (Bombus lucorum) ***Tree bumblebee (Bombus hypnorum) ***Garden bumblebee (Bombus hortorum) Heath bumblebee (Bombus jonellus) Ruderal bumblebee (Bombus ruderatus) Broken-belted bumblebee (Bombus soroeensis) Red-tailed bumblebees ***Red-tailed bumblebee (Bombus lapidarius) Red-tailed cuckoo bee- Bombus rupestris ***Early bumblebee (Bombus pratorum) Red-shanked bumblebee (Bombus ruderarius) Bilberry bumblebee (Bombus monticola) Ginger-yellow bumblebees Social bumblebees ***Common carder bee (Bombus pascuorum) Brown-banded carder bee (Bombus humilis) Moss carder bee (Bombus muscorum) Great yellow bumblebee (Bombus distinguendus) Shrill carder bee (Bombus sylvarum) Social bumblebees Buff-tailed bumblebee (Bombus terrestris) Short haired bumble bee – Bombus subterraneus Cryptic white-tailed bumblebee (Bombus cryptarum) Northern white-tailed bumblebee (Bombus magnus) Social bumblebees Buff-tailed bumblebee (Bombus terrestris) 5 WNE 2019 Status This bee is not regarded as being scarce or threatened. **Bombus terrestris is one of the main species used in greenhouse pollination in certain countries Identification Lengths, queen 20-22, worker 11-17, male 14-16. Forewing lengths queen 18 mm, worker 13 mm, male 14 mm A large species with dark yellow bands at the front of the thorax and middle of the abdomen Queens are the only caste which actually have buff-coloured tails In workers and males the tails are white, although males in particular often have a narrow but distinct yellow-buff band at the front of the tail.