THE CODLING MOTH IX MICHIGAN. 



69 



week of the month, when a pronounced warm spell set in, which 

 advanced rapidly the growth of vegetation. The mean temperature 

 for May was decidedly above normal, and an abundance of sunshine 

 prevailed. The United States Weather Bureau pronounced the heal 

 for the month unprecedented. Thunderstorms were frequent , accom- 

 panied by high winds and excessive rainfall. This weather condition 

 continued without interruption throughout the greater part of June, 

 when severe storms occurred, which caused great damage to orchards 

 and the fruit crop. During the period from the 11th to the 18th, at 

 the height of the emergence period of the spring brood of moths, a 

 markedly low temperat ure prevailed, accompanied by frequent rains, 

 which caused a sudden and prolonged delay in the appearance of the 

 moths. The weather conditions during July were also very excep- 

 tional. The first week of the month was marked by excessive heal 

 and great dryness, while during the latter half of the month decidedly 

 cold weather prevailed, with frequent local showers. August in most 

 respects was normal, while September was marked by sharp alterna- 

 tion of warm and cold periods and a frequency of rainfalls. During 

 October, and particularly during November, cool weather prevailed, 

 which delayed considerably the time for the maturity of many 

 second-brood codling-moth larvae. 



Table LXIX. — Temperature records taken in the outdoor rearing shelter, showing maxi- 

 mum, minimum, and average daily temperatures, Douglas, Mich., 1910. 



Note.— The records from Apr. i to 20, Inclusive, were taken from Mr. Tillinghast's records al Douglas, 

 Mich. 



