April, ’18] 
BECKER: WOOLLY APHIS 
245 
or the covering over the entrance to the infested single seed less im¬ 
penetrable than they were made by the larvae. The action of the cot¬ 
ton gins may result in loosening the silk spun by the larvae sufficiently 
to allow for the entrance of the mites. 
Any larvae that come out of the seed in a mass of seed where Pedi- 
culoides occurs abundantly are almost certain to be attacked and killed 
by this mite, especially late in the season. 
The two principal natural enemies are then Pimpla and Pediculoides. 
Pimpla occurs in some numbers but the bollworm campaign in Egypt 
should result in all the bolls remaining in the field after the crop being 
destroyed before the time of the greatest emergence of the parasite, 
and Pediculoides occurs in numbers only in the storehouses later in 
the season. When the ginneries are equipped with machines for treat¬ 
ing the seed as it leaves the gins, the predaceous mite will cease to be 
of any importance in connection with the control of pink bollworm in 
cotton seed. 
NOTES ON THE WOOLLY APHIS 
By Geo. G. Becker, Fayetteville , Ark. 
Owing to the war and to the uncertainty of concluding investigations 
as planned, the writer is submitting in this paper the results of investi¬ 
gations with the woolly aphis, Eriosoma lanigera Haus., which had 
as their aim (1) the working out of the life-history of the insect in the 
Ozarks, (2) studying the relative immunity of various hosts of this 
insect and of the relationship of these hosts to the species, (3) studying 
the immunity of Northern Spy stock to the attacks of this species, 
and (4) determining whether Eriosoma cratcegi Oestlund is a synonym 
of Eriosoma lanigera Hausmann. 
In the Ozarks the species winters on elm in the egg stage and on the 
roots of apple and in wounds, knots and rough places on the trunk 
above the ground, of apple and Crataegus as apterous vivipariae. The 
occurrence of overwintering apterous vivipariae above ground on apple 
or Crataegus is uncommon in this latitude as the aphids seem unable 
to withstand the low temperatures. 
The overwintering eggs on elm probably hatch sometime between 
the first and the middle of March. In 1916 we found stem-mothers 
in about the third instar by the 30th of March. At this time the 
buds, with the exception of the infested ones, had not pushed through. 
The second generation begins to make its appearance by the first 
of April. In 1915 a stem-mother was found on April 20 with about 
20 or more young, in 1916 we found a stem-mother on April 6 with 
