486 
Observations on the various Insects 
sown wheat was sprung out of the ground : consequently it could 
not lay its eggs in that. The soil is rather stiff, with a gravelly 
bottom." 
I shall now proceed to give the observations made on the ravages 
of these insects, and their economy, in France. In 1812 the 
Societe d'Agriculture de la Seine was officially consulted by the 
Minister of the Interior upon the subject of the considerable 
ravages made in divers parts of France, especially in the environs 
of Paris, by the destructive insects attacking the corn-crops. 
These insects lodged between the leaves of the corn, and ate the 
young stems at the termination of winter. The greater part of 
the attacked plants withered and perished upon the spot towards 
the end of the following April. The celebrated naturalist, Olivier, 
was charged by the Society of Agriculture to study and pubhsh 
the history of these insects in their Transactions, but his death 
prevented their completion, and the premature demise of M. 
Audouin again retarded this work; and it has been resumed by 
Dr. Herpin and M. Guerin-Meneville. 
9. Chlorops lineata? 
"In 1812 it was observed that the corn recently planted pre- 
sented, both before and after winter, alterations, occasioned by a 
birva situated above the roof, which ate the leaves in the centre of 
the plant, causing it to turn yellow^, and then to perish.* 
" In 1839 Dr. Dagonet, at Chalons-sur-Marne, and M. 
Pliilippar, detected again some larva? which caused in the spring 
a considerable swelling of the young wheat-plant above the joint, 
destroying the central leaves and the plant itself. Towards the 
end of April or in May these larva? were changed to the fly named 
Chlorops. Olivier was perplexed to explain how the eggs laid in 
May could be preserved and transported to the young wheat- 
plants, which are only sown in the October following. The 
pairing of the sexes takes place towards the end of May or the 
beginning of -lune, and the female is soon occupied in laying her 
eggs upon the stem of the wheat, which then commences to show 
the car ; the egg is deposited towards the lower part of the ear, 
at the bottom of the sheath of the leaves. About fifteen days 
after, there issues from the egg an oblong larva, yellow, and with- 
out legs, which attaches itself to the stem of the corn, imme- 
diately under the ear; it nourishes itself by nibbling apart of 
the surface of the straw, whicli is then very tender ; it there traces 
and excavates an external groove about two millimetres broad 
and one or two at most in deptli, but whicli never penetrates uito 
* Vide Dr. Herpin"s paper in the Memoirs of the ' Soc. Iloyale et Cen- 
tiale d'A{jiiculture,' 1842. 
