The Progress of the Hessian Fly. 
437 
recent years, but it seems impossible that such tiny flies could 
be carried so far by the wind. Curtis was of opinion that the 
turnip STiw-^y, At Italia spinartim," might have been transported 
to our shores by the winds settino^ in from Norway, Holland, or 
France." * Curtis also quotes Mr. Marshall, a careful observer, 
who calculated that " the turnip saw-flies might be transported 
from the southern cape of Norway to the coast of Norfolk in 
ten hours, and as they can live five or six days without food 
they could cross from the most eastern confines of Russia 
probably before they were exhausted." The turnip saw-fly is a 
much larger and stouter insect than the Hessian Fly, and has 
a considerably longer life. It may perhaps appear absurd to 
entertain the notion that the Hessian Fly is wind-borne, but it 
must not be forgotten that the prevailing wind in Great Britain 
in the spring is from the east, generated in the Arctic Ocean, 
and passing through Russia. 
The annexed table shows the counties in England which are 
known to be infested, the districts or parishes in which the 
insect has been discovered, and the extent of the injury 
occasioned by it. 
Table I. 
Name of County. 
Bedfordshire 
Berkshire 
Buckin crhamshire 
Cambridgeshire .. 
Essex 
Hampshire . . 
Hertfordshue 
Huntingdonshire . 
Kent 
Lincolnshire . . 
Norfolk 
Northamptonshire 
Northumberland . . 
Nottinghamshire . . 
Oxfordshire .. 
Somersetshire 
Suffolk 
Wiltshire 
Worcestershire .. 
Yorkshire 
District or Parish infested. 
("Ampthill, Dunstable, Houghton ■! 
\ Eegis, Potton, Sandy, WobarnJ 
Basildon 
Stony Stratford 
iDuxford, Foulmire, Long Stan-'j 
ton, Meldreth, Royston, Steeple I 
Slorden, Trumpington, Wil- j 
lingham j 
Great Wakering, Halstead 
Lyraington, Peterstield .. .. 
IBuntiugford, Hertford, Hoddcs- 
1 don, Ware 
Oflbrd d'Arcy, St. Ives 
Extent of Injury. 
Considerable in places. ' 
Slight. 
Very slight. 
Not much injury, but 
a general attack in 
these parishes. 
Slight. 
Very slight. 
II (Serious, especially at 
/\ Hertford. 
Slight. 
Halstead, Higham Very slight. 
fAneaster, Billingboro', Deeping.Vf Somewhat serious, par- 
\ Donington, Grimsby, Sleaford ) i\ ticularly near Grimsby. 
(Long Stratton, Morningthorne,! -vt j. i • • 
I Tiireston .. ^ot much injury.. 
Kettering, Sutton, Wansford . . Not serious. 
Alnwick. Belford Slight. 
Newark Slight. 
Goring Heath Very slight. 
Bridgwater 1 Very slight. 
Long INIelford, Sudbury . . . . ! Slight. 
Dowaton I Slight. 
INIalvern, Redditch i Slight. 
Goole, Hull, Holderness . . . . 1 Serious in plac3s. 
* Of. cit. 
2 G 2 
