• Sim Elliott

Agglomerations of Ivy Bees (Pett Level) and Sea Aster Bees (Rye Harbour) 13.09.21


Whist surveying Pett Level for the Bumble Bee Conservation Trust's Short Haired Bumblebee Reintroduction Project on Monday 13.08.32 we came across, in the morning, this agglomeration of Ivy Bees, Colletes Hederae on/in the sandstone outcrop (from the Ashdown Forest sandstone series) of Toot Rock, Pett Level. In the afternoon, two of the experienced surveyors, Peter Greenhalf and Morgan, showed me an agglomeration of Sea Aster Bee nests they had found last week at Rye Harbour


Ivy Bees Colletes Hederae


A recent addition to the list of European bees, being described as new to science in 1993. Previously this bee had been misidentified as both Colletes halophilus and C. succinctus by various authors. It is very closely related to both of these species, especially C. halophilus. Colletes hederae Schmidt & Westrich,1993 | BWARS

There were about 60 fresh males out.

T

hey only appear when the Ivy flowers - for a few weeks. Adults live for about 6 weeks. Females gather pollen to feed the larvae that will emerge from their eggs. They lay multiple eggs in nesting tubes - in separate chambers. Once they have mated the males will die, and once the females have collected enough pollen and laid their eggs they die.


The tubes for the eggs are mined in soft rock - in this case sandstone from the Ashdown Forest outcrop which enters the sea at Fairlight Cliffs. When the pupae pupate the young bees will remain in their holes eating the pollen until the ivy blooms again in 10 months time.


Ivy and ivy bees have a symbiotic relationship. Ivy bees migrated from Europe about 4 years ago and our now spreading north. Ivy is pollinated by other insects - otherwise there wouldn't be any Ivy - mostly hoverflies, other flies, late bumble bees (e.g Buff-tailed Bumblebees) and late-appearing Butterflies.

A recent arrival in Britain, with the first confirmed records from Dorset in 2001. By 2016, the bee had spread across Southern England and South Wales, northwards and eastwards to colonise most of East Angla, the Thames and Severn Valleys. The species is now well established in South Wales and in 2014 was recorded in north Wales for the first time. Since the 2016 season, there has seen expansion northwards with new records from Nottinghamshire, Yorkshire, County Durham (Whitburn) and southern Cumbria. Also well known from the Channel Islands with confirmed records from Alderney, Guernsey, Herm, Jersey and Sark. It is widespread elsewhere in western Europe and it appears to be spreading rapidly, with records from Austria, Belgium, Croatia, France (including Corsica), Germany, Greece, Italy (including Sardinia), Luxembourg, The Netherlands, Serbia, Slovenia, Spain and Switzerland. Previous reports from Cyprus are likely to be of the close congener C. brevigena Colletes hederae Schmidt & Westrich,1993 | BWARS


Male Colletes Hedera




[In] “The Imperial Dictionary of the English language” published in 1883, several interesting and different definitions can be found. Toot; Saxon – totian – to project, Icelandic/Norse tota or tuta – a teat or teat like protuberance, these may give us an insight into the origins of the name. References to “Toot Hills” (natural or artificially created) can be found elsewhere, it seems they may have been used as lookout points. Much of Pett level is on low lying land; the Toot stands out quite clearly above this. 8,000 years ago the land was 40ft lower than it is today, moving on a few thousand years and the level had risen by 40ft with the area being covered by forest. At around 2,000 years ago the land was sinking again but this time the inhabitants were reclaiming it from the sea. This sheer cliff face of Ashdown sands shows that Toot Rock was eroded by tidal action. Looking at the surrounding flat land I wonder if the Toot would have once stood by itself as a small island in the sea.


In the second world war a battery was built on Toot Rock

Photo above from Toot Rock – Pett Level Preservation Trust


Aggregation of nest holes


Ashdown Formation: Siltstones and silty fine-grained sandstones with subordinate amounts of finely-bedded mudstone and mudstone arranged in rhythmic units ("cyclothems") commonly divided by thin pebble beds. In southeast Sussex, around Hastings, the argillaceous parts of the "cyclothems" are well-developed and a series of clay seams, the informally named Fairlight Clays, is well exposed in the cliffs at Fairlight Cove. Here, this argillaceous part of the Ashdown Formation comprises dark grey finely-bedded mudstones and mudstones, commonly patchily red-stained, with abundant iron carbonate pellets (sideritic mudstones and sphaerosiderite nodules) at some levels. British Geological Survey BGS Lexicon of Named Rock Units - Result Details



Views from Toot Rock




Sea Aster Bees Colletes halophilus






BWAS record: This bee is particularly common in East Anglia and by the Thames estuary, but it occurs more sporadically along the southern coast of England. Records for the Channel Islands were misidentifications for This bee is particularly common in East Anglia and by the Thames estuary, but it occurs more sporadically along the southern coast of England. Records for the Channel Islands were misidentifications for Colletes hederae (Schmidt & Westrich).


Status (in Britain only) Listed in Falk (1991) as Nationally Notable (Na).


Habitat Associated almost exclusively with coastal habitats. Found on both dunes and the firmer soil behind beaches.


Flight period Mid-August to mid-October, and occasionally into early November.


Pollen collected Nest cells are mainly provisioned with sea aster (Aster tripolium) pollen (C O'Toole, pers. comm.).


Nesting biology Nesting aggregations, which are sometimes very large, occur in bare soil (e.g. surfaces exposed by land slippage), in artificial mounds of soil, and even in the sides of rabbit burrows. Nesting sites may be subject to occasional inundation by the sea. A nesting aggregation at Scolt Head Island, Norfolk, was reached by the highest spring tides, and the bees were observed trying to reach their burrows, which were submerged in about 7 cm of water (Field & Foster, 1988). On the Norfolk coast, bees have been seen emerging from waterlogged mud (D B Baker, pers. comm.). The nest architecture is similar to that of C. succinctus and has been illustrated by O'Toole and Raw (1991): a cluster of five to six cells radiates from the end of a short, curved burrow. Males may occasionally be found roosting in groups of up to a dozen on grass stems (P Kirby, pers. comm.).(Schmidt & Westrich).


Status (in Britain only) Listed in Falk (1991) as Nationally Notable (Na).


Habitat Associated almost exclusively with coastal habitats. Found on both dunes and the firmer soil behind beaches.


Flight period Mid-August to mid-October, and occasionally into early November.


Pollen collected Nest cells are mainly provisioned with sea aster (Aster tripolium) pollen (C O'Toole, pers. comm.).


Nesting biology Nesting aggregations, which are sometimes very large, occur in bare soil (e.g. surfaces exposed by land slippage), in artificial mounds of soil, and even in the sides of rabbit burrows. Nesting sites may be subject to occasional inundation by the sea. A nesting aggregation at Scolt Head Island, Norfolk, was reached by the highest spring tides, and the bees were observed trying to reach their burrows, which were submerged in about 7 cm of water (Field & Foster, 1988). On the Norfolk coast, bees have been seen emerging from waterlogged mud (D B Baker, pers. comm.). The nest architecture is similar to that of C. succinctus and has been illustrated by O'Toole and Raw (1991): a cluster of five to six cells radiates from the end of a short, curved burrow. Males may occasionally be found roosting in groups of up to a dozen on grass stems (P Kirby, pers. comm.). Colletes halophilus Verhoeff, 1943 | BWARS






Female


The Sea aster mining bee (Colletes halophilus) is a rare bee restricted to the margins of salt marshes in East Anglia and the Thames Estuary, with occasional populations along the south and east coasts. The UK supports nationally important populations, with the bee restricted globally to the North Sea coastline.


The bee is named after its preferred food source, Sea aster (Aster tripolium), which flowers at the same time as the bee’s August emergence when they collect pollen and nectar for their young. However, climate change and sea level rise are causing their saltmarsh habitats to be lost, with further impact on the bee from development pressure in their Thames Estuary populations.

Habitat loss has led to mitigation for various invertebrates, creating features such as beetle bunds, scrapes and bee banks, while unplanned opportunities can be created in rock piles, sand pits, road embankments and sea walls. Sea Aster Mining Bee | Buglife projects





Sea Aster, Tripolium pannonicum\ is not only pollinated by Sea Aster Bees; here is a Hoverfly of the Eristalis genus; mimicking a bee


Here is a Sea Aster being pollinated by a Buff-tailed Bumblebee at Cuckmere Haven on 10.09.12


Distribution

Sea aster can be found scattered across the coast of the UK, although it is much sparser in the north-east of Scotland.

Habitat

Often found in salt-marshes and estuaries and occasionally on cliffs. Sea aster is scattered throughout the British coast, although is absent from parts of north-east Scotland.

Best time to see

Flowers from July to October.

Did you know?

Asters are also known as Michaelmas daisies due to their late flowering period. Sea Asters particularly are a valuable source of nectar for late butterflies like the Red Admiral. This fact may also explain a traditional name given in Dorset and Somerset: Summer's Farewell. Plantlife :: Sea aster



Here is a Sea Aster being pollinated by a Sea Aster Bee at Cuckmere Haven on 10.09.12


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