affecting the Corn- Crops. 
495 
and iridescent, but sliglitly sniok)^ ; the costal nervure extending 
beyond the submarginal one to the mediastinal nervure (tig. 
31, 7i) ; all the nervures are pitchy, the two transverse ones are not 
very remote ; balancers with an oval ochreous club ; legs six, 
longish and slender, base and tips of the four anterior tibiae ferru- 
ginous ; the base of the first joint, in all the tarsi, is of the same 
colour: length J line, breadth 2 lines (fig. 31 ; r, the same magni- 
fied). Obs. — Some specimens are smaller and more slender; pos- 
sibly they are the males. 
This appears to be a much more formidable enemy than the 
Chlorops tccniopus, for the ten or twelve stalks I opened were filled 
only with powder at the base, every portion of the young ear being 
consumed ; indeed the destruction was complete. 
Let us now pause for a moment, and reflect upon the extra- 
ordinary fact, that our corn, the staff' of life, is placed in the power 
of this pigmy race ; and that, destined as man is to earn his bread 
by the sweat of his brow, yet famine, accompanied by its conco- 
mitants disease and death, may overtake him, notwithstanding 
his industry, and let his prospects be ever so promising, througli 
the united operations of the insect race. How wonderfully dis- 
played, therefore, are the wisdom and goodness of the Creator, in 
so nicely balancing the destroyer and his parasitic enemies as to 
keep man, naturally prone to indolence, ever on the alert ; and yet, 
when the countless hordes of noxious insects fall like an irresistible 
plague upon his crojjs, that hand which is ever ready to befriend 
mankind, arrests the scourge. Myriads of parasitic insects are let 
loose, multiplying as their prey increases — the threatening scourge 
passes over with less loss than could have been anticipated, and 
the succeeding year, to the astonishment of the farmer, instead of 
the mischief being increased, not an insect enemy is to be seen. 
1 may now be permitted to show, with regard to these little flies, 
the way in which the Creator himself has devised the means of 
arresting their multiplication. In rearing the Chlorops and Oscinis 
I often found that even more parasites than legitimate flies issued 
from the infested stems, and their history I shall lorthwilh relate. 
I bred a kind of Ichneumon from the Canada wheat, which suf- 
fered from the maggots of the Chlorops in 1841, and the grower of 
it transmitted another specimen. Likewise, on opening the spikes 
of barley from Sarsden in October, I invariably found, on the inside 
of the inner spathe enclosing the incipient ear, an empty j)upa- case, 
from 1 to 3 inches from the base, which had either produced the fl)'^ 
(^Chlorops tcBniopus), or this Ichneumon, called Coclinius,* one of 
* This is the genus Chccnon of my works ; but Nees ab Esenbeck having 
previously characterised the group under the above name, mine is super- 
seded. 1 should not have referred my insect to Nees's genus had not Mr. 
