Megachile Megachile Are Commonly Known As Leaf- Cutter Bees
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Megachile Megachile are commonly known as Leaf- cutter Bees. Seven species are found in Norfolk. Their mandibles work like scissors to cut pieces out of leaves or petals to form their nests. Several species make their nests in crevices or holes in timber whereas others use holes in sandy ground. Those requiring timber tend to be absent from the coastal strip, whereas those which nest in the ground often have a coastal bias in their distribution. All have two submarginal cells on the forewing and the tongue is quite long. Their name comes from the long tarsal claws which lack an ariolum between. Their characteristic posture, with tail in the air on alighting, makes these bees easy to spot. Megachile centuncularis female. It is often possible to identify Leaf-cutter Bees from good photographs. The scopa hairs beneath the abdomen differ in colour between species, but the scopa needs to be seen without pollen. Males can be distinguished from females by the male’s lack of a scopa and their longer antennae. They emerge about a week earlier than females and for the first few days, before it fades, their hair is bright ginger-brown. The males of three species have distinctive white swellings on the front tarsi and the male of another species has very green eyes. Bees in the genus Coelioxys are brood parasites of Megachile. Megachile ligniseca female cutting a leaf. Thriplow Cambridgeshire 13th August 2014 Megachile centuncularis ‘bee hotels’. Rose leaves or petals are often Females have pale hair on the clypeus and used in gardens. thorax, but there are some dark hairs on top of the head. The abdomen has pale marginal Parasites Coelioxys inermis. bands at the edges of tergites 1-5, with hair length decreasing from T1-T5. There are bands of sparser, longer hairs on T1 and T2. The scopa is entirely orange and the hairs protrude outwards making them visible from above. Males have pale hair on the clypeus, a mixture of dark and pale hairs on the top of the head and thorax. The abdomen bears similar marginal bands to those in females. Flight times June-August Distribution One of the commonest Leaf- cutters in the county, but there are few records from the west. Scarce on the coast, Megachile centuncularis female taking nectar nd though reported from Scolt Head. from a garden Coneflower. Weybourne 2 August 2015 Megachile centuncularis 4 3 2 1 0 9 2000 – 2014 8 1980 – 1999 Pre 1980 5 6 7 8 9 0 1 2 3 4 5 Habitat Heathland, commons, gardens, waysides, Breckland rides. Megachile centuncularis male on garden Marigold. Weybourne 3rd July 2013 Flowers visited Garden Agyranthemum (Asteraceae), Alkanet, Bramble, Crown Daisy, Fleabane, Green Coneflower, Hemp agrimony, Lamb’s-ear, Lesser Knapweed, Meadow Cranesbill, Meadow Vetchling, Purple Loosestrife, Ragwort, Nesting Nests are made in a variety of cavities in wood, buildings or hollow stems, including Megachile cirumcincta Females have long body hair which is black on the head and also on tergites 4-6. The scopa is brown at the base and black at the tip. Males have white clypeal hairs and an expanded white area of cuticle on the front tarsi. Flight times May-August Distribution This is the rarest Leaf-cutter in the county, but there are recent records from dunes at Caister and at Great Yarmouth (TS 2007 & 2015). There are also records from Horsey Dunes 1958, Scolt Head 1975 and from the Brecks 1998. Megachile circumcincta 4 3 2 1 0 9 2000 – 2014 8 1980 – 1999 Pre 1980 5 6 7 8 9 0 1 2 3 4 5 Habitat Coastal dunes Flowers visited Bird’s-foot Trefoil. Nesting Nests in sandy ground. Not observed in Norfolk. Parasites Coelioxys spp. Megachile leachella Females have pale body hairs with a tint of Distribution This is largely a coastal species, brown on the head and top of the thorax. but there is a record from Roydon Common There are complete white marginal bands on 1996 and one from Santon Warren 1986. all tergites and a characteristic pair of white hair patches on the last tergite. The small size Megachile leachella of this species is also a clue to identification. 4 3 2 1 0 9 2000 – 2014 8 1980 – 1999 Pre 1980 5 6 7 8 9 0 1 2 3 4 5 Habitat Sites with loose sand or sand dunes where small sandy cliffs are present for Megachile leachella female on Wild nesting. The north-east cliff faces are not used Mignonette. Weybourne Camp 12th August but places with loose sand at the cliff-top can 2015 be, for example West Runton beach car park. Males have white hair on the clypeus and orange-brown hair on the top of the head, Flowers visited Greater Bird’s-foot Trefoil, thorax and abdomen. There are complete Bramble, Catsear, Charlock, Crucifer sp., marginal white bands on the tergites. T6 has a Fleabane, Haresfoot Clover, Hawkweed, covering of pale hairs and bears short Heather (Ling), Oxford Ragwort, Ragwort, terminal spines. The eyes are a vivid pale Restharrow, Sheepsbit, Wild Mignonette. green. They are often observed basking on sandy ground close to nest sites. Nesting Nests are made individually on sloping or level sandy surfaces. Parasites A small form of Coelioxys mandibularis attacks this species in large dune systems on the coasts of Kent, Sussex, South Wales and Lancashire but it has not been recorded in Norfolk. Megachile leachella males showing green eyes; Holkham 8th Jule 2009. Flight times June-September Megachile ligniseca Megachile ligniseca male (faded) at nest hole Females are large with pale brown hair on the in bee hotel. Thriplow Cambridgeshire 19th clypeus and thorax and black hair on the top July 2015 of the head. There are long pale hairs on T1 Flight times June-September and T2 and pale marginal bands. The scopa is white anteriorly, grading to pale orange at the Distribution Moderately common in the east back. The dark hairs on the surface of the last and in the Brecks. No records from the north- tergite are flattened against the body and the west or the Fens. tip of the abdomen has a small indent. Males Megachile ligniseca have pale hairs on the clypeus, pale brown hairs on the top of the head and thorax and 4 pale marginal bands on the abdomen 3 consisting of moderately long hairs. The 2 abdomen is almost parallel sided and has a 1 notch at the tip. 0 9 2000 – 2014 8 1980 – 1999 Pre 1980 5 6 7 8 9 0 1 2 3 4 5 Habitat Commons, heathland, river valleys, mature dunes, gardens, open Breckland and brownfield sites. Flowers visited Garden Aster, Bramble, Burdock, Creeping Thistle , Dandelion,Field Scabious, Fleabane, Bell Heather, Lesser Knapweed, Melancholy Thistle, Purple Loosestrife, Spear Thistle. Megachile ligniseca female. Thriplow Nesting Nests in hollows in wood or stems. Cambridgeshire 11th August 2014 Parasites Coelioxys elongata observed at a garden nest site in Cambridgeshire. Megachile maritima which he often clung to as the pair fell to the Females are large and broad with brownish ground. hairs on the clypeus and thorax and varying amounts of black hair on the head, thorax and Flight times June-August abdomen. The scopa has whitish hairs. Males are large and broad with ginger-brown hair Distribution A coastal species also occurring when fresh. The fore tarsi are expanded with at sandy inland sites near Norwich and in the a white cuticle fringed by white hairs. The Brecks. hind tibia and tarsi are swollen. Males move Megachile maritima rapidly from flower to flower and sometimes defend territories. 4 3 2 1 0 9 2000 – 2014 8 1980 – 1999 Pre 1980 5 6 7 8 9 0 1 2 3 4 5 Habitat Coastal dunes and inland sites with bare sand. Nesting Nests in sandy ground, sometimes in Megachile maritima male on Bramble. aggregations (SF) Weybourne Camp 9th July 2015 Flowers visited Bramble, Haresfoot Clover, Sheepsbit, Restharrow, Ragwort, Vipers Bugloss, Greater Knapweed. Parasites Coelioxys conoidea (qv). Megachile maritima male (faded), grooming antenna. Winterton Dunes 17th August 2015. This bee repeatedly returned to the stem from which he launched attacks on other bees when they alighted on nearby Bramble flowers. His target included bumblebees Megachile versicolor Females are similar in size and appearance to Habitat Found in areas of flowery grassland M.centuncularis. The scopa is orange but with with scrub, including mature dunes such as dark hairs on sternites 5 and 6. The marginal Scolt Head and Winterton. It also occurs in bands on the abdomen are less prominent woodland rides including Swanton Novers than in M.centuncularis and the hairs on T6 Great Wood and shrubby heathland such as are flattened against the body rather than Kelling Heath. being erect. Males are also very similar to Megachile versicolor M.centuncularis and need microscopic 4 examination of the sternites to separate. They have more reddish apical tarsal segments (SF). 3 2 1 0 9 2000 – 2014 8 1980 – 1999 Pre 1980 5 6 7 8 9 0 1 2 3 4 5 Flowers visited Alkanet, Bird’s-foot trefoil, Meadow Vetchling, Spear Thistle. Nesting Usually uses hollow stems (SF). Megachile versicolor female on Spear Thistle. Parasites Coelioxys inermis is known to be a Kelling Heath 15th August 2011. cleptoparasite. Megachile versicolor (probably) male on Alkanet. Kelling Heath 29th June 2013 Flight times Late May-August Distribution Widespread but not common. Megachile willughbiella Flight times June-September Females are large and broad with brownish hair. They differ from M. maritima in Distribution Widespread and fairly common. generally having less dark hair on the thorax Megachile willughbiella and abdomen.