affecting the Corn- Crops. 
487 
the interior canal of the straw. This furrow reaches from the base 
of the ear to the first superior knot, with some exceptions; for 
example, wlien the larva perishes, or when it is full-grown before 
having attained the first joint. 
" When nearly arrived at this spot, the larva has usually ac- 
quired all its growth ; it is then transformed into a pupa, and 
fixes itself generally towards the middle of the furrow which it 
has scooped out on the exterior surface of the stem. In the fol- 
lowing September the Chlorops hatches, which would live during 
many weeks, and then deposit her new eggs upon the rye and the 
corn quite recently sown. 
" The stems of the wheat attacked by the larva; proceeding 
from the second laying of the Clilorops present some differences 
so singular and remarkable, that it is surprising no one has up to 
the present time ascertained the cause ; these alterations are 
gciierally attributed to a defect of vegetation, occasioned by cer- 
tain uncongenial variations of the seasons. The stalks thus 
attacked are scarcely more than half the height of those which 
are healthy ; their maturation is retarded considerably ; they are 
still very green when the others have become yellow from the 
effect of ripening ; the ears have not yet emerged from between 
the leaves which sheath them ; they are short, small in bulk, and 
contain but few grains ; these, moreover, are starved, concealed, 
and curved; lastly, all the series or files of grains situated on the 
side where one finds the longitudinal channel hollowed out by the 
larva are entirely abortive, and contain no grains." 
It appears that in July, 1840, the pupa and perfect insect were 
alive, and in May the infected stems were abundant, and, from 
the number of ears which were injured where the researches were 
made, the loss was estimated at one-seventieth part of the wheat- 
crop. Dr. Dagonet says, " The number was at least as consider- 
able in our country, where one could not set a step without meet- 
ing with some ears not disengaged from their envelopes. If we 
add to these ravages of the second laying, the considera\)le num- 
ber of young plants which perished in consequence of the attacks 
of the Chlorops prior to and after winter, we shall be convinced that 
this insect is a very formidable Fcourge to agriculture." 
10. Chlorops Herpinii, Guer. 
Dr. Herpin also obtained a 3fusca from larv8e which only 
attack the ears of the barley, antl which Guerin has named Clilorops 
Herpinii,* and he says that it resembles the C. glabra oi Meigen,| 
* Guerin's Memoirs, p. 30, pi. 2, fig 9. 
t System. Beschr., v. G, p 149, No. 20. 
