710 
peared withered, tough, and brown, yet not 
wounded: at this period the larve were trans- 
formed into pups, which were found in clusters 
inside of each leaf-sheath, at the first joint next 
to the crown of the root. On the estates of the 
Duke of Saxe Coburg, at Weikendorf and in 
other parts of that neighbourhood, whole fields 
were destroyed. The larve were found to live 
in society, forming a sort of nest between the 
straw and the sheath. They are said to pene- 
trate into the tube of the straw: however that 
may be, they deprive the stem of the sap, and it 
consequently withers and dies. The larve are 
of a pale green colour, with a minute black dot 
above; they do not exceed two lines in length; 
and they live from about three weeks to a 
month: the pupa is brown, and enclosed in a 
case. It was several weeks before the fly hatched ; 
it is extremely small and delicate, scarcely so 
large aS a common gnat; the body is clothed 
with short black hairs; the thorax is very con- 
vex, smooth, and shining; the scutellum pro- 
jects, and is rounded behind; the breast being 
sometimes of a golden yellow colour, the abdo- 
men brownish ; the wings are blackish; the 
deep yellow of the base sometimes extends to 
the nervures, where it is gradually softened off: 
the poisers are yellowish white ; the base of the 
thighs is golden yellow. The female has a black 
streak on the abdomen. The above descriptions 
do not agree with Say’s; and I see, by a para- 
graph in the Entymological Transactions, Mr. 
Herrick, of New Haven, North America, had in- 
formed Mr. Spence that the accounts hitherto 
published concerning the natural history of the 
Hessian fly were very erroneous: he considered 
it to be referable to Meigen’s genus Lasioptera ; 
and it is attacked by five parasites, two of which 
belonged to the genera Hurytoma and Platygas- 
ter. Mr. Spence also observed, at a previous 
meeting of the Entomological Society, that Dr. 
Hammerschmidt’s Cectdomyta, which is the Hun- 
garian one, is specifically distinct from Mr. Kir- 
by’s C. triticz; and that Say’s C. destructor, called 
the Hessian fly, is different from either. The 
female of the American species lays in the au- 
tumn not more than eight eggs, which are intro- 
duced by her ovipositor between the sheath and 
the stem, close to the base, where the larve feed 
as soon as they hatch, and are said to live 
through the winter with their heads downward ; 
but the mischief they cause is not discoverable 
until the wheat is more advanced. A parasite, 
called by Mr. Say Ceraphron destructor, but which 
may possibly be a Pteromelas in the opinion of 
Mr. Westwood, though smaller than the Cecido- 
mya, proves so formidable an enemy, by depo- 
siting its eggs in the larvee, that few of them 
become pupz; otherwise, Mr. Say believes that 
their wheat-crops would be totally annihilated. 
Kollar also found the majority of his pupae so 
full of a similar parasite that he felt convinced 
the crops would not be attacked by the wheat- 
WHEAT-FLY. 
midge the following year; which Prediction was 
completely verified.” 
The Chlorops pumilionis injures the young 
stem or central shoot of the wheat plant after it 
has risen a considerable way above the ground. 
The genus to which it belongs comprises up- 
wards of twenty British species, which may often 
be observed in great numbers on umbelliferous 
plants, and not rarely in houses, during the 
months of autumn; and it is characterised by 
the face being naked, the forehead tomentose, 
the seta of the antennee distinctly two-jointed, 
the abdomen oval, the feet naked, the costal 
nerve of the wing extending to the tip of the 
submarginal, and the prevailing colour, in most 
cases, being brown with various stripes and spots 
of bright yellow. The wheat-fly species bears 
the name of pumilionis or ‘dwarfish,’ in conse- 
quence of its dwarfing the wheat-plants which it 
attacks, destroying their proper stems, and 
causing them to throw out many lateral shoots 
which seldom attain any considerable height. Its 
predominant colour is black; the under side of 
the head and two longitudinal lines on the thorax 
are yellow; the under side of the body is pale 
yellow, with two black spots on the mesoster- 
num; the halteres are white; the legs are ash- 
grey with black tips. The maggot is small and 
white, the body composed of eleven well-defined 
rings, the head pointed at the end, black at the 
tip, and resembling the letter V in shape. The 
pupa is yellow, smooth, and shining, and rather 
more than the twelfth part of an inch in length. 
The Chlorops pumilionis caused great alarm in 
Britain about 50 or 60 years ago, in consequence 
of being mistaken for the American wheat-midge ; 
and it was first noticed in a scientific way, about 
that time, by Bjercander in Sweden and by Mr. 
Markwick in Britain. It attacks ryemuch more 
frequently than wheat in Sweden and other 
northern countries. Byjercander did not succeed 
in observing it deposit its eggs; but he found 
its larve in great plenty from the 23d of April 
till nearly the end of May, when they became for 
the most part fully grown. He could not dis- 
cover any holes in the stems of the plants; and 
he thence inferred that the eggs or larve must 
enter at the top of the leaves, and that the fly 
when matured forces its way upwards and es- 
capes. Mr. Markwick found the larvee lodged 
in the centre of the stem of wheat plants just 
above the root; and he observed that, by the 
end of March, many of them were full grown and 
passing into the state of pupe. He did not see 
the deposition of the eggs any more than Bjer- 
cander; and he indulges in some conjectures as 
to the manner in which they had been intro- 
duced into the field, concluding that it could not 
well be by means of the manure, as that consisted 
entirely of lime. What we know of the pro- 
ceedings of other insects, in similar cases, leaves 
little room to doubt that the eggs were placed on 
the plant by the fly itself. “ The larva and chry- 
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