Andrena Bees of Norfolk Identification Guide Andrena Bees Occur in All Continents Except Australia and Antarctica
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Andrena bees of Norfolk Identification Guide Andrena bees occur in all continents except Australia and Antarctica. Over 1400 species have been described worldwide, with 67 in the British Isles. 44 Andrena species have been recorded in Norfolk, of which 41 have been seen post-2000. The term ‘mining bee’ derives from their habit of making nest holes in the ground. Pollen is carried by hairs on the hind legs and also within curved hairs under the propodeum. Some Andrena species collect pollen from just one plant family, such as Willows, and are termed oligolectic, whereas others use a wide range of pollen sources and are termed polylectic. The short tongue generally limits Andrenas to flowers with a short corolla as a nectar source. The time of year a bee is seen and the flowers it visits can often assist with identification. Bee Genera All bees, except for parasitic bees, carry pollen back to their nests for feeding larvae. In the British Isles, only Bumblebees and Honeybees have a true pollen basket on the hind tibia. A pollen basket is a broad shiny area with a row of long hairs on each side, which holds a pellet of pollen. Most other bees, including Andrenas, carry pollen on specialised areas of hair called a scopa, meaning a brush. The hairs of bees are unique amongst insects in being feathery, a feature which assists in trapping pollen grains on the scopa. Other Norfolk bee genera with a scopa on their legs (so could be confused with Andrena) are: Anthidium, Anthophora, Colletes, Halictus, Lasioglossum, and Melitta. Colletes and Melitta are the genera most likely to be confused with Andrena. Colletes bees differ from Andrena in having a small head with a bi-lobed tongue and most have distinctive marginal bands on the abdomen. There are also small differences in wing venation. Melitta are very similar to Andrena, but have a swollen final tarsus joint. Andrena also differ from Melitta in having a facial fovea: the face inside the eyes is depressed and lined with velvety hairs, though this does not always show in a photograph. Bee Genera cont. Halictus and Lasioglossum have a ‘rima’ on the end of the abdomen – a mark rather like a hair parting, though this can be hard to see. Anthidium and Anthophora are distinctive, large, round-shaped bees, mostly with long tongues. Chelostoma, Heriades, Hoplitis, Osmia, and Megachile bees are easily distinguished from Andrena because they carry pollen beneath the abdomen, while Bombus and Apis carry pollen on their hind legs but in a pollen basket. Hylaeus bees and the parasitic genera Coelioxys, Epeolus, Melecta, Nomada and Sphecodes and have no pollen-carrying hairs. Bee genera There are 27 genera of bees represented in the UK. The images below show examples of each of the 27 genera, of which 24 occur in Norfolk. Eucera is presumed extinct in Norfolk and Ceratina and Xylocopa have not yet been recorded in the county, but might soon turn up. The number of species of each genus currently present in the county is shown in brackets. Note that sizes of bees are not to scale. Andrena (40) Anthidium (1) Anthophora (4) Apis (1) Bombus (18) Chelostoma (2) Ceratina (0) T.Benton Coelioxys(4) Colletes (8) Dasypoda (1) Epeolus (2) Eucera (0) Halictus (3) Heriades(1) Hoplitis (1) Hylaeus (8) Lasioglossum (22) Macropis(1) Megachile (7) Melecta (1) Melitta (3) Nomada (19) Osmia (6) Panurgus (2) Sphecodes(13) Stelis (3) M.Fogden Xylocopa (0) Andrena bees compared with a Honeybee (Apis) Andrena bees often look superficially like a Honeybee and some are almost as large, being up to 15mm in length, whereas the smallest are only about 7mm. Size varies greatly even within a species depending on the supply of pollen to each larva. Females are generally larger than males. Andrena bees, along with some other solitary bee genera, carry pollen along the length of the hind legs and under the thorax (above), unlike Honeybees (below) and Bumblebees which have a well defined pollen basket on the hind tibia. Identifying Andrenas On first acquaintance all Andrena bees look rather similar. This guide attempts to introduce them to the general naturalist, based on the author’s studies in Norfolk over the past 5 years. With the assistance of a digital camera it is possible to identify a good number of the 40 or so Norfolk species, and some can be identified in the field, especially when they are newly emerged. Those who become really interested might take their studies further using a stereo microscope to study pinned specimens, using keys. Females are usually easier to identify than males. The Andrena illustrated is a female because she is carrying pollen. Females have shorter antennae than males with 12 segments as opposed to 13 – sometimes possible to see in a good image. Behaviour often gives a clue to the sex of a bee, with females collecting pollen and making nests, while males patrol for females or wait to mate at nest sites. Naming Andrenas Very few Andrenas have a Tawny Mining Bee Andrena fulva female on common name. One exception apple blossom, Weybourne 7th May 2010 is the attractive Tawny Mining Bee, Andrena fulva, which is often seen making a nest on lawns or visiting blossom. Names have recently been invented for many solitary bees, but here only scientific names will be used. Index and Phenology of Norfolk's Andrenas. A dark square denotes overlap of first and second broods. Brackets = not recorded post-2000 Norfolk Cuckoo bee parasites (ref BWARS & Bees of Slide status F M A M J Jy A S O N Notes Surrey, Baldock) Andrena alfkenella 12 RDB3 Chalk ? None recorded Andrena angustior 14 Rare Nomada fabriciana (Andrena argentata) 16 Extinct? Calluna Nomada baccata Andrena barbilabris 17 Sphecodes pellucidus Andrena bicolor 20 harebell (2nd) Nomada fabriciana Andrena bimaculata 24 Scarce Nomada fulvicornis Andrena chrysosceles 28 Scarce Apiaceae Nomada fabriciana Andrena cineraria 30 Nomada lathburniana & goodeniana Andrena clarkella 33 Sallow Nomada leucopthalma Andrena coitana 36 Rare Nomada obtusifrons & roberjeotiana Andrena denticulata 39 yellow Asteraceae Nomada rufipes Andrena dorsata 41 ? None recorded Andrena flavipes 44 Nomada fucata Andrena fucata 47 Scarce Nomada panzeri Andrena fulva 49 Nomada panzeri & signata Andrena fuscipes 51 Calluna Nomada rufipes Andrena haemorrhoa 55 Nomada ruficornis Andrena hattorfiana 58 RDB2 Scabious Nomada armata (extinct Nfk?) Andrena helvola 62 Scarce ? None recorded Andrena humilis 64 Asteraceae Nomada integra [not recorded Nfk] (Andrena labialis) 68 Extinct? Fabaceae Sphecodes rubicundus Andrena labiata 69 Na Germander Speedwell Nomada guttulata Andrena marginata 72 Na Scabious Nomada argentata Andrena minutula 78 Nomada flavoguttata? (Andrena minutuloides) 80 Scarce Nomada flavoguttata Andrena nigriceps 81 Scarce ? None recorded Andrena nigroaenea 83 Nomada flava, fabriciana, goodeniana Andrena nigrospina 87 Rare Nomada goodeniana Andrena nitida 89 Nomada goodeniana Andrena ovatula 91 Heathland/sandy soils ? None recorded (Andrena pilipes) 87 Rare ? None recorded Andrena praecox 96 Sallow Nomada ferruginata Andrena proxima 99 RDB3 Apiaceae Nomada conjugens Andrena scotica 100 Nomada flava, goodeniana, marshamella Andrena semilaevis 104 Nomada flavoguttata Andrena subopaca 106 Nomada flavoguttata Andrena synadelpha 108 Nomada panzeri Andrena tarsata 111 Tormentil Nomada roberjeotiana [not recorded Nfk] Andrena thoracica 113 Nomada goodeniana & fulvicornis Andrena tibialis 115 Willows Nomada fulvicornis Andrena tridentata 117 Extinct UK? Asteraceae ? Andrena trimmerana 118 Scarce Nomada marshamella Andrena varians 121 Rare Blackthorn etc Nomada fabriciana, ferruginata, panzeri Andrena wilkella 124 Nomada striata Oligolectic species Blakeney Point Kelling Heath Buxton Heath Mousehold Heath Beeston Common (FF) Royden Common (MA) Abbey Farm Flitcham (EC) Warham Camp Cut off channel Foulden Common Stanta Caudlesprings (GN) Cranwich Sheringham Park Swanton Novers Great Wood Norwich Rosary Cemetery (TS) Strumpshaw Fen (TS) Holt Hall Ditchingham garden (DC) Weybourne garden (Author) Brundall garden (TS) Overstrand/Mundesley cliffs Weybourne Camp (MS) Caistor Quarry Outwell Fens Andrena alfkenella 4 Andrena argentata Heather 1 Andrena angustior 1 Andrena barbilabris 9 Andrena bicolor 19 Andrena bimaculata 12 Andrena cineraria 5 Andrena clarkella Sallows 9 Andrena coitana 2 Andrena chrysosceles 4 Andrena denticulata Yellow Asteraceae 8 Andrena dorsata 21 Andrena flavipes 13 Andrena fucata 4 Andrena fulva 14 Andrena fuscipes Heather 5 Andrena haemorrhoa 19 Andrena hattorfiana Scabious 6 Andrena helvola 2 Andrena humilis Yellow Asteraceae 5 Andrena labiata 2 Andrena marginata Scabious 5 Andrena minutula 18 Andrena minutuloides? 1 Andrena nigriceps 2 Andrena nigroaenea 18 Andrena nitida 15 Andrena ovatula 4 Andrena praecox Sallows 10 Andrena semilaevis 12 Andrena scotica 16 Andrena subopaca 10 Andrena synadelpha 7 Andrena tarsata Tormentil 1 Andrena thoracica 9 Andrena tibialis 9 Andrena trimmerana 3 Andrena varians 2 Andrena wilkella 6 Total spp. 1 20 9 18 19 14 15 7 16 10 12 17 20 10 12 14 17 8 7 11 17 7 18 13 4 Dunes Heathland Andrena species recorded at various Norfolk sites Calcareous grassland Wet commons Mixed acidic and alkaline heaths Woodland Silt fen farmland Gardens River valley dry woodland Soft cliffs & quarries In the species accounts below, ease of identification of the female is given by • F = identifiable in the field • P = identifiable from a good image • M = only identifiable using a microscope A guide to size is given as: very small, small, medium or large.