Further Records of Empididae

130

A REVIEW OF BRITISH

MACROLEPIDOPTERA

great rarity from the Scilly Islands, in a specimen of the Slender Burnished Brass (Plusia aurifera Hübn.) of which only two other authentic examples have been recorded this Century in the British Isles.

The autumn months brought several surprises. Not only were a good many of the Scarce Bordered Straw (Heliothis armigera Hübn.) noted, but by far the most interesting event was the remarkable abundance locally of Blair's Pinion (Graptolitha lapidea Hübn.). In the Isle of Wight this insect, of which there had only been a handful taken since its discovery in 1951, suddenly appeared in quantity both at light and at sugar in mid-October, while an increased number were also recorded from the coast of Sussex.

This phenomenon definitely gave indication that the species was breeding now over here, probably on different kinds of cypress.

A most interesting Observation was that, unlike its near relatives, this insect does not hibernate, but lays its eggs in the late autumn.

Most of the usual autumn moths were fairly numerous in the later months of the year, but the Vanessid butterflies were distinctly scarce. Very few Commas (Polygonia c-album Linn.) were to be seen. One of the final rarities of the year was a specimen of the Yellow-underwinged Pearl (Uresiphita polygonalis Schiff.) which was taken on the Essex Coast. It is almost our scarcest Pyrale.

So ended quite a productive and interesting season in spite of the very unpropitious conditions during the summer months.

FURTHER RECORDS OF EMPIDIDAE (DIPTERA, FAMILY XXIII) IN SUFFOLK

By C. GARRETT-JONES, M.SC., F . R . E . S .

In 1951 Claude Morley compiled a list of 142 flies of this family known to occur in Suffolk (see Trans. S.N.S. Vol. VII p. 108).

It seems that he overlooked a paper of mine in the Ent. Mon. Mag. (1950) Vol. LXXXVI p. 260, which recorded seventeen species of the genus Hilara, all found Aying at Fiatford in the first fortnight of July, 1946. Nine of these are not included in Morley's list. In the notes that follow, a few records of Empididae from Iken (R. Aide) are included also, making a total addition of 12 species to the previous county list. Clearly, many more species of this large family await collection, for example by anyone visiting Fiatford for the purpose at another season. The species now added to the list are marked with an asterisk.

FURTHER RECORDS OF EMPIDIDAE IN SUFFOLK

Genus:

131

RHAMPHOMYIA.

Species : *Rh. maculipennis Zett.—Iken, 23 - 26.V.47. One pair, no prey collected.

Rh. tarsata Mg.—Iken, 23 - 26.V.47. Males (1 with prey), 1 female.

Genus:

HILARA.

Species : H.fuscipes F.—Fiatford, 1 - 14.vii.46. The commonest species, often clouding surface of R. Stour in vast numbers. Probably the staple diet of dragonflies.

Mating mostly in evening. Iken, 30.vi.46 and 6.viii.46. Both sexes resting under bridge.

H. ängulata Strobl.—Fiatford, 8.vii.46.

One male at 6 a.m. Iken, 31.V.40. Two males. *H. aeronetha Mik.—Fiatford, 6 and 13.vii.46. Males with prey above small brook through meadows; females swept from grass. Not seen to skim water.

H. thoracica Mg.—Fiatford, 4, 5 and 14.vii.46. Over pool and brook, flies at dusk or in deep shadow by day. Pair taken with prey.

H. litorea Fln.—Fiatford, 13.vii.46. Swarms over brook, including pairs which dropped their prey into bottom oif n e t ; rarer over river. Iken, 6.viii.46. One female over a dyke. *H. anglodanica Lbk.—Fiatford, 1 - 14.vii.46. Over pools and brook, males with prey in mornings, mating pairs afternoons only; appears to roost high in trees. *H. nigrina Fln.—Fiatford, 12 and 13.vii.46. Females swarming over river, morning; mating occurs evening and probably morning. Iken, 6.viii.46.

Over river and dyke. *H. cornicula Lw.—Fiatford, 2 - 10.vii.46. Over pools and brook, in shade ; mating seen in evening.

H. monedula Coli—Fiatford, 1 - 14.vii.46. Common over all waters, females swarming some feet up and mating occurring throughout day. Iken, 30.vi.46.

H. maura F.—Fiatford, 2 and 7.vii.46. Singlespecimens in afternoon, over brook and in lane. Iken, 4.vi.40. A pair with prey. This species occurs away from water more than others of the genus. *H. griseifrons Coli.—Fiatford, 2 and 9.vii.46. By day singly, over mill-pool and brook. Not taken in cop. or with prey.

132

FURTHER RECORDS OF EMPIDIDAE IN SUFFOLK

*H. chorica Fln.—Fiatford, 2.vii.46. One of each sex over mill-pool. Iken, 6.viii.46. Over dyke. (Also occur in urban areas.)

H. lurida Fln.—Fiatford, 1 - 14.vii.46. On all waters, preying and mating from 7 to 10 p.m., and perhaps later.

(But a male seen at Chiswick appeared to imbibe honey-dew from an alder leaf.)

H. rejecta Coli.—Fiatford, 1 - 14.viii.46. Over river only, males swarm just over water and may not skim it for prey as other species do. *H. morata Coli.—Fiatford, 5 and 13.vii.46. Single males in evening, over brook and river ; may be crepuscular in habit, as H. lurida. *H. apta Coli.—Fiatford, 12.vii.46. One male over river among swarm of H. rejecta. Previously not recorded from counties East of Oxfordshire. *H. manicata Mg.—Fiatford, 1 - 14.vii.46. Males swarming over brook, without prey. Iken, 6.viii.46.

A male and a pair with prey, over dyke. *H. obscura Mg.—Iken, 6.viii and 27.ix.46. Swept from undergrowth by dykes ; male and female swarms over river. Pairing seen, but prey not found.

H. quadrivittata Mg.—Iken, 6.viii.46. Males with prey, over river. Not common.

H. hirtella Coli.—Iken, 25.ix to 2.X.46. Heavy swarms over river, preying and mating in progress.

Also seen over dykes and resting on herbage.

H. primula Coli.—Iken, 14.V.40. One male.

H. fulvibarba Strobl.—Iken, 30.vi.46. One male, one female.

Genus:

CLINOCERA.

Species : *Cl. stagnalis Hai.—Iken, 30.ix.46. One male taken as prey to H. hirtella, over river.

The prey recorded with many of these species are listed in the earlier paper mentioned above. These are fascinating flies to study, for not uncommonly as many as six species of Hilara may swarm together over suitable water, the stronger preying on the weaker. Prey-relationship " chains" of three or four links, all within the genus Hilara, can occur. I do not know whether the male flies of most species suck the prey which they pick up from the water, or whether they catch it and parcel it up only in order to present it to a hovering female. Another most interesting line of study would be to find the larvae of these Empids (presumably in earth, leaf mould or rotting wood), and to find out what roles they play as predators.