“26- 
during the light hours. Records of soil-temperature suggest one reason 
for this daily period of emergence. Simultaneous records of tempera. 
ture in shade, in sun at the surface of the soil, end at depths of 1, 
4, 6, 9, and 12 inches below the, surface have been made. Of these lo 
cations, the temnerature of the soil surface exposed to the sun is most 
veriable. It reaches the highest degree Curing the day and the lowest 
of any location during the night. Temperatures .at.15 inches deep are 
least veriable of any location mentioned. At a depth of 6 inches the 
doily variation in temperature is about 10° F. on a warm summer day. 
At this depth the highest temperature was observed from about 6 tame 
until about § p.m., that is, about sunset, and. at a time when shade is 
extending and soil temperatures on the surface are falling rapidly. 
At a depth of 12 inches, the highest temperature was recorded from 
{ p.m. to midnight, and the coldest period occurred from 11 a.m. to 
12m. The Heliothis pupae rest at depths averaging from 3 to 6 inches 
below the surface of the soil, For pupae of average depths the warn 
est periods to which they ore subjected during the day are, therefore, 
from late: afternoon to & or 9 p.m. n other words, the periods during 
which moths usually emerge are those shortly following the subjection 
of pupae to the highest temperatures of.the day in the positions where 
they rest." 
Harmless larvae of March flies associated with injurious:tipulid 
larvac.—--According to W. B. Cartwright, Sacramento, Calif.) “FPomeeeus 
eral years Bibio larvae have been found in habitats of tipulid larvae. 
Although easily “2istinguished, their presence causes some confusion in 
hasty examinations early in the season. In February several colonies 
of 45 to 250 larvae each were found with Tipula albocincta Doane at 
Sacramento. The Bibio larvae mass together and apparently do not mi- 
grate singly, and very little as a whole. Their food consisted entirely 
of dead vegetation and leaf mold. Under similar conditions, chance 
associations with Tipula simplex Doane at Altamont and Winters, and 
T. acuta Doane at Ukiah have been noted. Moist, rich spots under trees. 
anc. in the uncultivated strips alons streams and fields are favorite 
habitats." 
Wireworm activity at the end of February.--Mr. Cartwright reports 
that wireworms male a sudden attack on the plots of wheat hybrids at 
the Sacramento, Cealif., laboratory on Februery 27. The ground was wet 
from recent rains but warm. To prevent destruction of some mursery 
rows, hand picking was necessary. Two hundred larvae per day were re— 
moved by one person from the plants and the adjacent soil--a process 
not difficult, as the larvae were neor the surface of the ground. 
Wheat plants with early injury showed a deeper green coloration of in 
fested. tillers. Plants having severed parts were wilted or yellowed. 
The coloration of the plants gave clues to the rows needing immediate 
attention. The infestation was not uniform over the plots. 

