g4 
The following paper was next presented: . 
THE DESTRUCTIVE PEA LOUSE, A NEW AND IMPORTANT ECONOMIC 
SPECIES OF THE GENUS NECTAROPHORA. 
By W. G. JOHNSON, College Park, Md. 
I have to report here one of the most remarkable instances of the 
sudden appearance of an undescribed species of insect over a wide 
area, Which has ever come to my notice, and which is, perhaps, one of 
the most unique in economic entomology. For centuries hidden in 
obscurity, a little green louse appears suddenly over wide areas, 
destructively attacking the field pea, a plant, heretofore, practically 
exempt from the ravages of insect foes. My attention was called to it 
May 18, 1899, by Mr. C. H. Pearson, one of Maryland’s largest oyster, 
fruit, and vegetable packers, in the following communication: 
One of my pea fields is entirely covered with a small green louse, which is sapping 
the life out of it, and if anything can be done to prevent it I want to do it at once. 
I made a personal inspection of Mr. Pearson’s place, containing about 
1,000 acres, Known locally as the **Susquehanna farm,” situated along 
the Chesapeake Bay, in St. Mary County, at the mouth of the Patux- 
ent River, May 24, 25, and 26. Upon myreturn to my office, the 27th, 
and after a careful consideration of the conditions and facts. I summed 
up the situation in a letter to my friend, Dr. L. O. Howard, United 
States entomologist, which I quote in part, herewith, as follows: 
I have just returned from southern Maryland, where I have been making an 
examination of the outbreak of aphids attacking peas in that section. 
I write you this statement knowing that you are interested in anything of this 
kind, and at the same time to give you an opportunity to see with your own eyes 
what I have attempted to describe below. The place can be reached within a day’s 
ride down the Potomac, and I am satisfied you would be well repaid for the visit 
to see the conditions existing. At the same time we would not care to have a public 
announcement made at the present time, as it might militate against the owner 
in a way that would be unpleasant for him, as his loss is estimated now at between 
$20,000 and $25,000. 
Without a question of doubt the destruction caused by this insect ( Nectarophora = 
Siphonophora) is the most complete I] have ever experienced. It is certainly a sad 
sight to look over a 100-acre field of peas and see them literally incrusted and coyv- 
ered with this insect. There is practically no hope to save even a fractional part of 
the crop in this field. Itis one of desolation. As far as one can see the plants are 
shriveled, withered, and in many instances the leaves are blackish, looking as if 
a fire had gone over the surface of the ground, scorching them. The whitish cast 
skins of the insects stuck to the drooping leaves in the honey dew, which has been 
excreted by the insects everywhere over the entire field, gives one the impression 
that a terrible plague has surely visited that section. The attack is not confined to 
this particular 100 acres, but is present in adjoining fields. The owner of this estate 
has planted this season 1,800 bushels of peas, besides using with them 130 tons of 
commercial fertilizers, covering an area of 600 acres of land in all. 
To say that the condition is discouraging to the owner is not necessary, in view of 
the fact, that at present, we are helpless so far as a practical remedy is concerned. 
It is safe to say that if the present weather conditions prevail very much longer, a 
