The Diptera of Suffolk: Family xv, Stratiomyidae

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THE DIPTERA OF SUFFOLK. (Cont. from vol. vi, p. 174.)

FAMILY xv: STRATIOMYIDAE. (sec. Verrall, Brit. Flies 1909, pp. 51-229—Brit. spp. 54. List 1945 has only 52.)

Pachygaster ater, Panz.—Generally distributed on bushes: Melford and beside the Stour at Sudbury in 1916 (Harwood), Ipswich 1908 (Bennett), Foxhall, Bramford, Shrubland, Barham Oak Wood, Parham Wood, Monks Soham garden and windows, Frostenden, Kessingland, Barnby Broad; Tostock 1900 (Tuck), Timworth and Livermere (Nurse), Tuddenham Fen, Eriswell, Brandon.

P. Leachi, Curt.—Much rarer, usually quite scarce and local: not uncommon near Orford in 1908 (Bloomfield), occasionally on Monks Soham windows and poplar in lanes in July, on flowers at Farnham; one at Livermere in 1913 (Nurse), Brandon Oxycera analis, Mg.—A single $ swept from Sparganium in the River Deben at Cretingham on the warm and dull 6 June 1943 at 2.30 p.m. (P. J. Burton).

O. pygmaea, Fln.—Found in numbers at Tuddenham Fen on 29 July, 1880 (Verrall, p. 93) and never again.

O. formosa, Mg.—Extremely local, but gregarious when it occurs : Orford (King), numerous on bracken and Spiraea flowers at Foxhall 10 Aug., 1902 and 21 July, 1904, several in Barnby Broad, 1906. Sucking honey-dew on Butterburr leaf by Deben at Brandeston, 11.30 a.m. 25 July 1942.

O. tenuicornis, Mcq—Very scarce about Sudbury (Harwood), sparingly in marshes near the Deben 1 July 1907 (Verrall, p. 100), Orford (King). [Swept from Galium verum, Gosfield in Essex, 24 July 1902.—Morley.]

O. pulchella, Mg.—Rare, usually found singly: in Sudbury garden (Harwood), one in Suffolk and probably at Felixstow (Piffard) where two or three occurred at the harbour in 1923 ; in spiders-web on Cypress in Monks Soham garden 13 Aug. 1917, and on Burr-reed in R. Deben at Brandeston 17 July 1943 ; Bramfield 1942 (Hocken); in any numbers solely in the Frostenden brick-fields 14-30 July 1922-6.

O. 2-lineata, Fab.—Not uncommon nor always in estuarine marshes: Suffolk (Verrall, 113), not rare about Sudbury in 1916 (Harwood), Felixstow in Aug. 1896 (Piffard), Brandeston, Blythbro Heath, Frostenden, Oulton, Barnby Broad; common in Burgh and Bradwell marshes before 1834 (Pagets), still occurs in former; Beccles, Shipmeadow; Bungay (Tuck), Timworth (Nurse), Barton Mills 1915 (Harwood), on Brandon pales 1937 and staunch.

Nemotelus pantherinus, L., uliginosus, L., notatus, Zett.—All three are nearly equally common on herbage in our salt estuaries from Felixstow up the coast to Burgh Castle, though

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THE DIPTERA OF SUFFOLK

much more numerous in certain years and the last seems restricted from Hemley as far only as Southwold. The other two also occur in fresh-water marshes : the former at Cornard Magna (Harwood), Bungay Common ; Timworth and W. Stow (Nurse), Tuddenham and Barton Mills (Verrall), Brandon; the latter at Foxhall, Ipswich, Butley Ferry, Oulton, Bungay; Thetford (Curtis).

N. nigrinus, Fln.—Less numerous than the above and never in salterns, wide spread in marshes : Suffolk (Verrall), Cornard Magna (Harwood), Ipswich, Bramford ; Orford (Bloomfield), Blythbro Wood ; common about Timworth (Nurse), on dry heath at Knettishall in July, 1941, in Tuddenham Fen, Barton Mills, Mildenhall, Brandon in June.

Odontomyia argentata, Fab.—" One old specimen on my co bears the label ' Kirby' " (Verrall, 134), extremely local: a series at Henny, within ten yards of Suiffolk, in 1928 (Harwood), a few on Kingcup leaves in sun by Deben at Brandeston, in N.E. air, 15 May 1943 (Burton); both sexes at Ampton in May 1911 (Nurse), one in Tuddenham Fen on 28 May 1924; Barton Mills 1911 (Collin), by Dr. Sharp probably at Mildenhall about 1901 (Verrall, 134); a halfdozen sitting on reeds to avoid water then infloodrendering the Brandon staunch, where they occurred, a temporary island on 25 May, 1923.

O. tigrina, Fab.—Not nearly as rare as the last, with which a halfdozen were on Brandon reeds in 1923 : one among Junci beside stream in Bentley Woods 18 May 1921, two only (in forty years) sitting on plants beside Monks Soham moat, 1-13 June 1912-4, and common at a Cratfield pond on Alisma, May 1943 ; two on reeds by Drinkstone pond, 17 June 1896 (Tuck) ; Ampton and Bamham (Nurse), a $ at Tuddenham, 20 July 1880 (Verrall, 139).

O. ornata, Mg. et angulata, Panz.—Both these rare kinds certa occur in our extreme bogs, as they do in Essex, Cambs. fens and Norfolk broads : the former was detected in Monks Soham moat on 14 June 1947; and the latter rests upon a single $ caught by Verrall in Tuddenham Fen on 20 July 1880 [though common at Shapwick, Somerset, July 1933 and Catfield, Norfolk, August 1936].

O. viridula, Fab.—Locally quite common in marshes, more usually salt ones on coast, sometimes on Cnicus palustris flowers Suffolk (Verrall, 146), Cornard Magna, common in Felixstow salts 1898, Ipswich, Bramford, Blythbro Wood, Southwold salts, Kessingland, Oulton Broad, Herringfleet, Burgh Castle, Shipmeadow; Tostock (Tuck), Tuddenham June (Nurse).

Stratiomys Chamaleon, Linn.—One female on Heracleum in lane bordering Letheringham-park Wood at noon, on 6 August 1918 (Elliott).

THE DIPTERA OF SUFFOLK

13

S potamida, Mg.—Rather rare and found always singly in woods or marshes, July-Aug. : in Sudbury garden (Harwood), on Heracleum flower at noon in Raydon Wood 1941, Ipswich district, 1894 ; Battisford (W. Baker); $ on moat of Hannings in Framlingham 1917 (Vinter), Brandeston, one in Monks Soham paddock ; Barnby Broad 1898 ; Bungay and Tostock (Tuck), Timworth and W . Stow (Nurse).

S furcata, Fab.—Oar least rare species, subgreganous, 6 June-21 Aug • Felixstow (Piffard), considerable numbers near Bawdsey ferry, 7 July 1894 (Verrall, 157), Southwold (Stanley) several on Heracleum flowers at Easton cliff, 1901-27 and Kessingland, 1949; Benacre Broad (Tuck), Oulton Broad, 1898 (Bedwell) and 1922, Burgh Castle, on Angeltca flower Barnby Broad, Shipmeadow, 1928 ; two by pond at Bamham, 1910 (Nurse). , ,. , S. longicornis, Scop.—Yery rare here and confined to brackish ditches—all Brit. loc. (except Wicken) seem coastal: Suttolk (Piffard), Felixstow (Verrall, 161); one sitting on an oaktrunk by brackish ditch beside the salt Orwell River at Wherstead, on 5 June 1897.

Chrysonotus bipunctatus, Scop.—Several Suffolk localities (Verrall, 170), but singly and quite rare, 13-27 Sept. only : on umbelflower at Foxhall, 1896; Glemham Magna circa 1860 (Bloomfield), Aying four feet high among hazel and hornbeam bushes in sun at 4 p.m. in Sotterley Wood, 1935, at moth-light at 9 p.m. in Wangford Wood, 1938 ; three or four at Tostock circa 1897 (Tuck).

Sargus flavipes, Mg.—Bury district in 1897 (Tuck), Ampton (Nurse), one on oak in Holborn marsh near Beccles, 25 Aug. 1898 ( M l y : Verrall, 175).

S. minimus, Zett. et nitidus, Mg.—Found nowhere but at Oriord in 1908 by M r . King of Glasgow.

5 . nubeculosus, Zett.—Found nowhere but a few in his Newmarket garden by M r . Verrall (Brit. Flies, 182).

S. cuprarius, Linn.—Less frequent than the next species 16 June-18 J u l y : fairly common at Sudbury (Harwood); Levincrton creek 1923, rare in Monks Soham garden and windows, Gorleston; Tostock in Aug. 1898 (Tuck) not uncommon on shrubs in Newmarket garden (Verrall, 184,755).

S. iridatus, Scop.—Common in country lanes and gardens 21 May-11 A u g . : fairly common at S u d b u r y ; Ipswich district r a r e ; Otley, Framlingham, frequent in Monks Soham garden, T h o r n d o n ; not common round Yarmouth (Pagets), Tostock in 1899-1900, Timworth.

Cloromyia formosa, Scop.—Among our most numerous Flies, from Bentley to Burgh Castle and Southwold to Newmarket, 11 June-27 July : sometimes at Monks Soham light in July ; prone to lay eggs promiscuously. I t breeds in Monks Soham tennis-court: a larva dug u p at roots of Plantago lanceolata

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THE DIPTERA OF SUFFOLK

there on 15 May 1916, produced a $ the next or following month, which laid sterile eggs.

Microchrysa polita, Linn.—No rarer than the last from Sudburv to Thetford and Lowestoft to Newmarket, 18 May-7 Aug., sometimes at light in July at Monks Soham ; where on 2 Aug. 1912, dozens were larvipositing, in cut kwn-grass that was three days old, and found upon dissection to be füll of maggots, not eggs.

M. flavicornis, Mg.—Widespread but never numerous, 30 May-10 Aug. : fairly common about Sudbury (Harwood), Felixstow and Orford (King), Monks Soham garden and windows in June, Dunwich, Reydon, Sotterley Park ; Tostock (Tuck), Timworth and Ampton (Nurse), Tuddenham Fen, Brandon ; Newmarket garden (Verrall).

M. cyaneiventris, Zett—Very rare : Orford in 1908 (King) ; one $ at Monks Soham light on 11 Aug. 1935.

Bens vallata, Forst.—Uncommon, 29 June-24 Aug. : Foxhall on ragwort flower, Bentley Woods, common on Theberton marshes at E. Bridge on 10 July, 1900 ; Barnby Broad on fir-trees ; Bury and Tostock (Tuck), Ampton and Bamham.

B. clavipes, Linn.—Common everywhere from Cornard to Yarmouth and burdock leaves on the Orford coast to Brandon staunch, late May-early Sept.

B. geniculata, Curt.—Rarer than in Norfolk : one beaten from sallow in Fritton marshes on 11 May, 1939.

B. chalybeata, Forst.—Most numerous of the genus from Sudbury to Gorleston and Blythbro to Wordwell, 16 May-11 June only, in cop. at Benhall Wood, 17 May 1935 and Foxhall, 27 May, 1907 ; bred on 14 March, 1900, at Ipswich from a small rat-tailed puparium taken there (doubtless in moss, like Curtis) the previous year.

B. Morrisi, Dale—Mixed with the last, apparently infrequent: three or four on Monks Soham windows, sometimes at 6 p.m., on 15 June, 1921 and 24 May, 1936.

Chorisops tibialis, Mg.—Generally distributed and not rare, 12 July-18 Sept.; never observed hovering in Suffolk (as many were at Thirsk in July 1937) : Sudbury, Ipswich at bryony flower, Staverton, Rendlesham, Snape, Monks Soham in cop. at noon on 5 Aug. 1918 ; Wangford Wood, Frostenden, Lowestoft, on umbel-flowers in Barnby Broad, Bury, Timworth, Tuddenham Fen. Xylomyia marginata, Mg.—Excessively rare : one on drawingroom window at Monks Soham, on 10 July 1924 (sole one in forty years there); one at Exning on 11 Aug. 1882 (Verrall, 227); Exning on 22 Sept. (Collin): tili found in small numbers, sitting on Black Poplar bark at Thorndon Fen in July, 1944.

Hence we possess 39 of the 52 British species.