Some interesting aculeate Hymenoptera records for 1999-2000
sometimes in large numbers, such as at East Tilbury silt lagoons, and collects pollen from composites,
especially yellow-flowered species such as ox-tongues Picris. It is confined in Essex to the East
Thames Corridor and several other coastal locations. It has recently been collected by Adrian
Knowles at Old Heath Cliff Paddock (TM0123) on 15 August 2000, by the author at Thorney Bay
(TQ7982) on 5 July 1999 and on several occasions in 1999 and 2000 at Northwick, Canvey (TQ7683).
Leal-cutter bees and cuckoo bees (Subfamily Megachilinae)
Cuckoo bees in the genus Stelis are generally scarce. The author collected one female of the Nationally
Rare (RDB3) Stelis ornatula at Northwick, Canvey (TQ7683) between 19 July and 3 August 2000.
The species should be considered endangered in Essex. The only other county records are from Mill
Wood Pit (TQ5978) and West Thurrock PFA lagoons (TQ5876), where females were collected by
the author in 1994 and 1996 respectively. The species is a cleptoparasite of Hoplitis claviventris,
itself a very rare and threatened bee in Essex, with recent records by the author from the Mill Wood
Pit site in 1994, St Clements Church tract in West Thurrock (TQ5977) in 1996, Temple Mills
(TQ3786) between 17 and 25 June 1999, Wennington silt lagoon (TQ5279) on 10 August 1998 and
Barking (TQ4682) between 27 July and 14 August 2000. The only locality where the bee was
present in any numbers was Mill Wood Pit. All the other sites are either threatened, or have also
been destroyed or severely damaged by development.
The important discovery of a single male Heriades truncorum (Insuffiently Known. RDBK) has
come to light when the author identified material collected by Colin Plant near South Ockendon
(TQ6081)on 13 August 1999. This is the first modern record for Essex, an old unconfirmed record
from Hainault Forest (Smith, 1846) being given in Falk (1991).
The Silvery Leaf-cutter Bec Megachile dorsalis (leachella) is a Nationally Scarce (Notable B)
species which nests in loose or friable sandy substrate fully exposed to the sun. It is present in large
numbers at East Tilbury silt lagoons (TQ6977) and formerly at Barking PFA lagoons (TQ4682)
where the weathered PFA ''dune' habitat has now been completely destroyed for development and
the bee appears lost. Adrian Knowles collected one female at Fingringhoe Wick (TM0419) on 18
June 1999, one female at the Tilbury EWT Centre (TQ6576) on 10 July 2000, and one male at Colne
Point (TM0912) on 19 July 2000. The author collected one male at the Wennington silt Lagoon
(TQ5279) in June 1999, one female at Thorney Bay (TQ7982) on 5 July 1999, and one female at
Pitsea (TQ7387) on 20 July 2000. He also found the bee to be numerous at Northwick, Canvey
(TQ7683) between 23 June and 24 August 2000, as well as still present at East Tilbury silt lagoons
in large numbers.
Nomad, flower bees and bumblebees (Subfamily Apinae)
The Nationally Scarce (Notable B) Nomada flavopicta, a cleptoparasite of the mining bees Melitta
leporina and M. tricincta, is restricted in Essex to the East Thames Corridor. Females were collected
by the author at Northwick, Canvey (TQ7683) on 21 August 1999, Anchor Field in West Thurrock
(TQ5977) on 25 July 2000 and Barking (TQ4682) on 27 July 2000. The Nationally rare (RDB3)
Nomada fulvicornis is a cleptoparasite of several mining bees in the Andrena carbonaria group, A.
spectabilis, A. bimaculata, A. nigrospina and A. tibialis. It also has a distribution concentrated along
the East Thames Corridor, but also with records in Matching, the Colchester area, Walton Naze and
Foulness (TR0393), where Roger Payne collected one female on 17 August 1998. Adrian Knowles
also collected one male at the Tilbury EWT Centre (TQ6576) on 10 July 2000 and one female at
Old Heath Cliff Paddock (TM0123) on 27 July 2000. The species was present in some numbers at
Wennington riverside (TQ5379) on 19 May and 14 June 1999 and, despite the loss of most of this
habitat, the author collected one female at the adjacent Aveley Bay (TQ5379) on 16 May 2000.
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Essex Naturalist (New Series) 18 (2001)