
i Ts 
Tests of the influence of soil moisture in fumigation with hydro- 
cyanic acid are reported by J. W. Lipp, Moorestown, who says: "Exami- 
nations were made on November 2 of two soil balls treated on October 
26 with 1/2 pound of 'Zyklon Discoids' per1,000 cubic feet for 2 hours 
(one tree was dry and one damp when treated). The treated trees stood 
outdoors the night following the treatment, were dampened and brought 
into a warm room the following afternoon where they remained until exa~ 
mined, when the soil ball, which was dry at the time of treatment, showed 
3 living and 22 dead larvae and the damp soil 18 living and 5 dead. 
A check tree showed 23 living larvae. Under the conditions mentioned 
it is evident that soil moisture is a decidedly limiting factor in HCN- 
fumigation." 
L. B. Parker, reporting on emergence of Tirhia malayana Cam. at 
Yokohama, Japan, says: "On October 30 nine adult Tiphia were noticed to 
have emerged from cocoons that had resulted from experimental rearing 
with adult females of Tirhia malayana (Japanese var.). Forty-three co- 
coons of the same lot, from which 200 cocoons were shipped to Moorestown 
on August 15, were placed in a glass jar with moist sphagnum moss and kept 
under laboratory conditions. It was from these 43 cocoons that the 9 
adults emerged (5 females, 4 males). The exact date of emergence is not 
known but must have taken place between October 20 and 30. The remain-— 
ing 24 cocoons were dead, having been killed by fungus. * * * The emer— 
gence of this species, not only in the laboratory but also in the field, 
would indicate that this species has two generations per year, at least 
an this locality. 
TRUCK AND GARDEN CROP INSECTS 
C. H. Popenoe, of the bramble insects investigations, Arlington, 
Va., reporting on studies of Aphis rubicola Oestlund, says: "Reproduc- 
tion, both asexual and sexual, maintained itself throughout the month 
of November. There was a heavy frost on November 7, the temperature 
reaching 26° F., but the plants in cages were not seriously injured, 
and there were no signs of damage to the aphids, which continued to pro-— 
duce both viviparously and oviparously. Both types of reproduction con- 
tinued throughout the month, although the peak of oviposition was reached 
during the first week. * * * There was a heavy frost the night of No- 
vember 27, the temperature dropping to 20° in the cages, but without in- 
juring the aphids." 
Life-history studies of the pea aphid (Illinoia pisi Kalt. ) at Mad— 
ison, Wis., according to John E. Dudley, jr., "were rapidly closed out at 
the end of November. From 25 stem mothers (which hatched from the win- 
ter eggs in the spring of the year) two direct lines completed the six-— 
teenth generation and eggs were laid for the beginning of the seven- 
teenth. For the whole season there were 234 mothers which produced 13,3556 
young and eggs, an average of 57 per mother. One hundred and fifty-eight 
