9254 Insects. 
cocoon. Thorax and wing-cases transparent yellowish green. Abdomen reddish yellow. 
Abdominal divisions and tip dark red.— H.. Harpur Crewe. 
Description of the Larva and Pupa of Eupithecia lariciata of Frey.—Var. 1.— 
Ground colour bright grass-green, somewhat darker on the centre of the back. Central 
dorsal line dark green. Anal tip of central dorsal line reddish. Subdorsal lines wanting, 
or so faint as to be searcely visible. Spiracular line whitish or pale straw-colour. Seg- 
mental divisions yellowish. Belly whitish, with a dark green central line. A long, 
slender larva, tapering towards the head. Resembles in appearance the larva of 
E. fraxinata of Crewe. 
Var. 2.—Ground colour yellowish red or reddish buff. Central dorsal line brownish 
olive. Subdorsal lines brownish olive, occasionally very faint. Spiracular line pale 
greenish yellow. Anal tip of central dorsal line reddish. Belly whitish, with a dusky 
central and two broad Jateral lines. Strongly resembles the larva of E. indigata of 
Hiibner. Feeds on larch and spruce fir. Full-fed the end of July. Pupa enclosed 
in a slight earthen cocoon. Rather long and slender. Thorax yellowish olive. Wing- 
cases deep green. Abdomen yellowish green, tinged with red. Abdominal divisions 
and tip red. This insect, which has only lately been ascertained to be British, was 
first taken, some three three years since, in Kent, by Mr. Eedle. During the present 
season Mr. Edward Hopley and Dr. Gill have again taken it in Surrey. The former 
gentleman most kindly sent me a small batch of impregnated eggs, from which I reared 
about ten larve. From these the foregoing descriptions were taken. The perfect 
insect appears at the end of May and beginning of Juve.—Jd. 
Immense Swarms of Syrphus Pyrastri-—Enclosed are some species of Diptera that 
are swarming here in countless thousands. My attention was first drawn to them on 
Sunday, the [4th inst., the walls of my house being literally covered with them. 
Yesterday they passed over this place in an eastward direction in large masses. At 
the Rey. C. Pritchard’s and other places they were seen passing continuously for six 
hours. One old lady in this place, the owner of a fine orchard, declares it to be a blight 
upon her apples, as they completely covered her trees yesterday in their eastward 
migration. Every house in this place is infested with them. No doubt you will receive 
notices of their occurrence in other places. I certainly think such an unusual occurrence 
worth recording.—H. Rogers; Freshwater, Isle of Wight, August 16, 1864. 
Postscript.—Since writing the foregoing communication I have gained the follow- 
ing additional particulars. I went to Freshwater Gate yesterday: there the dead bodies 
of these flies formed a line on the shore and under the cliffs more than four miles in 
length, viz., from the Needles to the Monument. Colwell Shore presented the same 
appearance, and millions were still flying about there, to the annoyance and discomfort 
of our lady visitors, many of whom seemed quite alarmed at the unusual occurrence. 
I then visited Yarmouth Bridge, where men are employed at the present time painting 
the rails, this being the direction the swarm had taken the day before. For fifty yards 
the rails were completely covered with flies firmly fixed to the wet paint. There were 
stragglers to the right and left, but this seems about the width of the main body. If 
you consider a mass fifty yards wide passing over for six hours, the number seems almost 
incredible-—H. Rogers ; August 18, 1864. 
[The flies sent are Syrphus Pyrastri. Mr. Rogers is quite right in supposing I 
should receive similar announcements from other quarters : I have been inundated with 
correspondence on the subject, generally accompanied with a demand for a remedy for 
this destructive pest. The history of the fly is on this wise : it is sent by an allwise and 
