ete 
JAPANESE AND sSIaTIC BEETLES 
Japanese beetle (Popillia 
Effect of abnormally cold weather upon Jap beetle larvae.—— 
Extraordinsrily | low temperatures orevai led “throughout , February. H. 
Fox and T. N. eae Mocrestown, &. J., report that during the 
month air temperatures below freezing were expr erienced on every: day; 
below 20° F. on 24 days; below 10° F. on 15 days; and below €° F. on 
4 days. In 1933, February had 22 days with températures below 32° F., 
8 days below 209 F., and 2 days below 10°F. The lowest air temper- 
ature recorded in February 1954 at the Jaboratory at Moores Vania N. 
Je, was -13° F., although at »oints within a few miles of the labo- 
ratory temperatures as Low ag ~18° F. were reported. The extremes 
and total range of temperatures guage 5 during February 1934 in the 
air and at certain soil depths are shown in the following table: 
ne nn + + +. 


of . 7 Of soil at ¢ depths of BAP i 
Temperature air pee be le GU ty git ae eee “Se 
Highest FS 6 ae SU Ry = BO «: cee “Sore oa7'O 36.4 38.2 
Lowest ee Wa at ee © Cee 2a 29.4 30.4 55.0 54.50 
Range ST U0 9.8 7.8 ar a.o Soe pe: K 4.2 
From what is known of the ability of the 1 arvae of the Japanese 
A Be i 
beetle to withstand cold, it is believed tet é pg et ‘to a teupera- 
ture of 15° F. or lower would ordinarily be fatal. © Examinations of 
soil samples iudicate.that there mey have ‘beén some mortality among 
the larvae close to the surf face; however, there is nO indication of 
any material reduction of ae larval population. The cold weather 
was accompanied by unvesually- heavy snowfall, and a snow cover of 
varying thicimess. on every day of the month probably accounts for’ the 
relatively light mortality. 
Effect of lack of food én derval mes tenorphosis .--Two series of 
emer 

25 third-instar larva have been reared by H. Fox and T. N. Dobbins 
in the incubator ie determine whether they would complete their 
development in the absence.cf an external source of. food. Larvae 
used in the aes were confined in individual salve boxes with sifted 
sterilized soil. Larvae for one series were collected from an 
asparagus Tield at Hamilton Square, N. J... All of these died. The 
other scries of larvae were taken from. grass sod ¢ et Princeton and 
four individuals were alive at the cad of January. One of these 
changed to a papa, which became: an adult (female) on February 8, 
the durution of the pupal. stage.in this instance being 10 days, which 
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