affecting the Corn-Crops. 
479 
(lant in one district, in all probability it will make its appearance 
simultaneously over the kingdom ; and this has been the case 
even with species that had up to a given period been very rarely 
seen. Such was the case with these caterpillars, as will be evident 
by comparing the following dates with the previous ones : for in 
the beginning of September I received examjiles from a friend in 
Surrey, saying that the rubbed out produce of some rye from seeds 
found in a sample of Spanish wheat in 1839, was full of them ; 
again, in August, 1841, the same party transmitted me more spe- 
cimens, the size of fig. 16, which I will describe, as they differed 
at this stage of tiieir growth from Dr. Calvert's fidUgrown ex- 
amples: one of t^em was pale green, with four reddish brown 
stripes formi^ three yellowish green lines down the back ; the 
head and pectoral feet were brown, the first thoracic segment 
slightly horny and shining, and each of the abdominal segments 
had four black dots between the stripes, as in the larger ones; a 
black dot characterized the spiracles, and there were three or 
four black dots on the thighs and feet, on the pale green, which 
extended under the body ; down the centre of the belly were 5 or 
6 dusky spots. I should not omit to mention, that I also received 
this caterpillar in the beginning of last June, from Mr. M. Saul, of 
Garstang, Lancashire, who discovered it upon the young wheat, 
but it did not appear to be very abundant : it was three-quarters of 
an inch long at that early period. 
Dr. Calvert also informed me that he was preserving the seeds 
of grasses, and consequently the grass is not cropped ; and as he 
finds these caterpillars feed upon the seeds, he suspects that they 
are thus nurtured imtil they are attracted by the wheat-crops; 
they are by far most abundant on the heads of grass in seed, par- 
ticularly the fescues and cock's-foot, and the grass seeds matured 
by the end of July and beginning of August are not infested by 
them. 
It seems probable that these caterpillars do not generally appear 
in great numbers, and only in their first skins, until the wheat-crops 
in many parts are harvested in good seasons ; but in the more 
northern counties they may prove very destructive to the standing 
corn, where the crops are later in arriving at perfection, and as 
they must often be carried into the barn or stacked with the wheat, 
their presence may be dreaded anywhere, especially when we find 
them injuring the corn to the extent observed by Dr. Calvert, who 
states that Colonel Le Couteur's improved Talavera, and many 
other wheats, had suffered to an extent of about one-third of the 
crop, and what is remarkable, they had not been detected in the 
neighbouring fields. Many of the ears I examined were very much 
more injured than the one represented at fig. 15; some of the 
grains had only a small hole in them, but multitudes were nearly 
