INSECTS AND OTHER ANIMAL Pests Insgurtous To Fietp Beans 971 
could be found in the field. On August 26 one male of H. cilicrwra was 
taken, and this was the only fly seen in 1918 after July 22. The con- 
ditions at Perry in that year were abnormal, for this region suffered much 
more for want of rain than did the surrounding places. The reduction in 
the number of flies appearing at Perry in 1919 is possibly due to this pro- 
longed dry period. 
TABLE 6. TrmMpERATURE AND Morsture Recorps OF THE UNITED STATES WEATHER 
Bureau at Rocuester, New YORK, DURING THE SUMMERS OF 1917 To 1920, INCLUSIVE 
‘(Records of marked variations from the Rochester records found at Perry are given in bold- 
faced type) 
Mean temperature Rainfall 
(Fahrenheit) (inches) 
Month 
1917 1918 1919 1920 Normal 1917 1918 1919 1920 | Normal 
INI WA Bes Sees AON 228 | 6ily ae 56 .4° 55.8° 56 .7° 3.16 1.75 | 5.20 0.78 2.94 
2.01 
SUNG Mes senor: 62.8° | 62.6° | 72.8° | 65.7° | 66.1° 6.40 2.40 2.96 1.15 | 3.13 
LIVIN yoo eibe oo eral face Latte “OR 22 W222) 160 82 70.4° 4.23 2.70 3.40 2.93 3.09 
1.03 1.21 : 
PAI PUSGA seers = 69 .0° ileroe 67.8° 70.3° 68. 3° 2.51 1.83 3.60 ilepyl 2.96 
1.34 5.70 
In July of 1919, the rainfall at Perry was again below normal, and the 
flies in the cages died rapidly after July 1. Between July 1 and July 20, 
the rainfall was only 0.67 inch, and the maximum temperatures for this 
period ranged from 65° to 96° F. After July 15 no flies were seen for two 
months and the specimens in cages all died. August of that year had 
nearly twice the normal rainfall. 
The temperature early in the summer appears to have an influence on 
the abundance of H. cilicrura. In 1917 the mean temperature for May 
was 49.2°, which is several degrees below the average for the month and 
is the lowest recorded since 1871. The maggots and flies during that 
season were the most numerous in the history of the insect. June tem- 
peratures in 1917 also were lower than the normal, and had been each 
year since 1913. 
H. cilicrura is an insect which in the past has been injurious for one year, 
or for a few successive years, and has then become of negligible importance 
for an indefinite period. This variation is undoubtedly connected to some 
extent with the moisture and temperature conditions of the early summer. 
Moderately low temperatures with an abundant rainfall in the spring 
appear to be favorable to the insect, while dry, warm weather during the 
summer is detrimental to its successful development. A succession of 
cold, wet years brings forth the insects in greatest numbers. 
