. TEMPERATURE AND APPEARANCE OF BEETLES. 119 
The effect of temperature in these records is obscured to a con- 
siderable extent by other conditions that affect the number of beetles 
caught by jarring, as winds, rains, proximity to hibernating grounds, 
and number of beetles previously caught. But the data seem to show 
that some beetles will become active at a mean temperature of 55 to 60° 
extending over three or four consecutive days, and that a mean 
temperature above 60° for several successive days will bring out the 
beetles en masse. After the beetles have once come out of winter 
quarters they may be jarred from the trees following periods with a 
mean temperature much below the degree required to bring them 
into activity, though such periods of cold weather greatly reduce 
the numbers caught. In Table LXVII is given a summary of the 
data in Table LXVI, showing the number of beetles caught at 
different temperatures for all five localities. 
It will be seen from this table that beetles have been jarred in 
considerable numbers following days with an average mean tem- 
perature below 55° and even below 50°. But by a study of Table 
LXVI it would seem that these beetles had been brought out by 
earlier spells of warmer weather and were already on the trees when 
the temperature dropped immediately preceding the jarrings. Prob- 
ably a mean temperature of between 55 and 60° is required to cause 
the beetles to leave their hibernating quarters. 
Taste LXVII.—Number of beetles of the plum curculio jarred at different temperatures, 
. all localities combined. 
Svereee ores 
ay, Average ZIM Average 
mean mean 
. 1 le: . Beetles I 
emp Jarrings. pen j ame tempera- | Jarrings. Cau ant, ee F nee 
. es ring _ tures ring 
since last 3 since last i 
jarring. jarring. 
ng? ig ett 
39 | Se Re Ie ei aed 57 3 69 23 
40 2 1 4 TROP eee cice| AAS Gaeee] MOREE cere 
41 ele seen cnc |aee ceeee ae 59 6 706 118 
PE eres ee | ein niern oct sea 60 4 351 88 
43 2 4 2 61 2 22 11 
44 2 76 38 62 3 221 7 
45 3 3 1 63 2 334 167 
46 4 38 9 64 6 361 60 
47 1 1 1 65 3 342 114 
48 2 68 34 66 5 301 60 
49 | 1 7 Te 67 6 991 165 
50 9 166 18 68 3 258 86 
51 4 102 25 69 4 1,212 303 
52 6 98 16 70 5 1,122 224 
53 3 95 32 71 4 1, 426 356 
54 4 99 25 72 2 138 69 
55 2 99 49 7 2 113 56 
56 5 124 25 74 2 303 151 
75 1 103 103 
| 
