affecting the Corn-Crops. 
483 
culturist, when combined with ihe facts recorded by my fellow- 
labourers in science. 
As the documents relating to these insects are very numerous, 
it may be as well to preface my narrative with an outline of their 
general economy. When the incipient ear is formed, but con- 
cealed in the sheath close to the first knot, or even at an earlier 
stage of growth, the wheat and other corn-plants often droop:* on 
opening the stem a maggot is found; this changes to a pupa 
higher up, from whence eventually emerges the legitimate fly, or 
some parasite which feeds upon the larva5. 'ITie earliest intimation 
we have of these pests is in the Stockholm Transactions, first by 
Linnseus, and secondly by Bierkander. Gmelin, Fabricius, and 
others have described the species in their woi'ks ; and subsequently 
we find an excellent paper in the Linnaean Transactions, as well 
as more recently the Memoir of MM. Herpin and Guerin- 
Meneville, besides notices in many other works, which I shall 
endeavour to embody in my narrative. 
8. OsciNis PUMILIONIS, Bierh. ; Chlorops glabra, 3[eig.? 
Bierkander | describes one of the species, which he calls the 
Ryeworm, and the following is his accurate accoinit of this insect, 
which he named Miisca jmmilionis :\ — " In the month of May, 
1778, I perceived some dwarf stems amongst the rye, from one to 
three inches lonof. On examininof them, I discovered that at their 
first joint there was a little worm, which caused this singular 
growth. In order to trace at leisure the metamorphoses of these 
worms, I took many specimens, which were put in a glass bottle. 
" The larva is white, two lines long ; it has ten segments ; the 
head is pointed, black at its extremity, forming a A. The first 
began to change to a pupa on the 25th of May. 
" The pupa; are yellow and sliining, a little more than a line 
long, depressed and annulated. They began to produce flies on 
the I2th of June. 
" The imago, or perfect fly, is a little more than a line long ; 
its head is yellow, and its eyes black ; it bears at the nape a black 
triangle : the black antennae are a little knotted, and produce some 
hairs : the thorax is yellow beneath, black upon the back, and 
marked with two slender yellow lines the whole length ; below 
and near to the abdomen is a yellow crescent- formed spot: the 
fore-legs bear two black spots: the abdomen is black above, yellow 
beneath, and is composed of four segments : the poisers are white : 
* This, it will be also remembered, is the case with the Wireworms. 
•!• Vide the Transactions of the Royal Academy of Stockholm, vol. 
xxxix. A.D. 1778, pp. 240 and 241 ; also the Transactions of the Linnaean 
Society of London, vol. ii. p. 79. 
X Thus named from its causing dwarf and abortive grains in the ears. 
VOL. V. 2 k 
