82 
such parts of the rows as had received two applications were cleared 
of the insects. 
On red clover I have seen this aphid multiply in spring until its 
numbers threatened the life of the plant, and then disappear, practi- 
cally, thru natural agencies ; this for five successive seasons. A heavy 
rain did the work assisted by the fungus Empusa aphidis and, second- 
arily, by the numerous and important — tho somewhat lagging — pre- 
daceous and parasitic insect foes of the aphid. Were it not for these 
influences the louse would become a pest of the first magnitude in 
spite of the vigor of the clover plant. Occasionally and locally it does 
become such a pest, as already related. 
Unfortunately, it can not be predicted whether the clover will be 
killed or not, and if one is unwilling to take the chances, the safest 
thing to do is to cut the clover just as soon as possible. Cutting and 
drying the clover will kill most of the lice at any time during the sea- 
son. 
The hordes of lice are for the most part the progeny of the fewer 
lice of May, in the same field. So it follows that spring pasturing or 
clipping back the clover would check the multiplication of the louse. 
The lice of April and May are the progeny of a comparatively 
few wintered females that entered the field the preceding year, and 
also of a few eggs laid the previous autumn in the first-year clover. 
Therefore it is advisable to cut or pasture the clover in the lattdr part 
of its first season — and this will not hurt the plant if done intelligently. 
Macrosiphum pisi Kalt. 
18Q9. Johnson, W. G.— Bull. No. 20, N. S., U. S. Dept. Agr., 
Div. Ent., pp. 94-99. 
1900. Johnson, W. G.— Can. Ent., Vol. XXXII., pp. 56-60. 
Chittenden, F. H.— Bull. No. 23, N. S., U. S. Dept. Agr., 
Div. Ent., pp. 33-37. 
Johnson, W. G.— Bull. No. 26, N. S., U. S. Dept. Agr., 
Div. Ent., pp. 55-59. 
Sanderson, E. D.— Bull. No. 26, N. S., U. S. Dept. Agr.. 
Div. Ent., pp. 69-72. 
Sanderson, E. D. — Bull. No. 49, Del. Agr. Exper. Sta., pp. 
14-24. 
Fletcher, James. — Rep. Exper. Farms Canada, 1899, pp. 
170-174. 
1901. Sanderson, E. D.— Can. Ent., Vol. XXXIII., pp. 31-39. 
Sanderson, E. D. — Twelfth Rep. Del. Agr. Exper. Sta., 
1900. pp. 169-186. 
Fletcher, James. — Rep. Exper. Farms Canada, 1900, pp. 
211-213. 
Chittenden, F. H.— Circ. No. 43, U. S. Dept. Agr., Div. 
Ent., pp. 1-8. 
1902. Sanderson, E. D. — Thirteenth Rep. Del. Agr. Exper. Sta.. 
1901, pp. 168-172. 
I 
