June, '13] TOWXSEXD: COTTOX SQUARE WEEVIL 305 



Ica and the foothill valleys represent six very distinct and conspicu- 

 ously contrasted sets of climatic conditions. 



Guayaquil is hot-humid throughout the year, with heavy tropical 

 rains. 



Piura is hot-arid from December to May, and cool-subhumid dur- 

 ing nights and mornings from June to November; practically with- 

 out rain, at most with irregular slight sprinkles or showers during the 

 warm season which very exceptionally become heavy rains known 

 only at long intervals. 



Lima is hot-subhumid to dilute subarid from December to May, 

 and cool-humid with continuous cloud-blanket and almost daily 

 drizzling mist from June to Xovem-jjer; practically never with heavy 

 rains, and very exceptionally with slight sprinkles or showers in the 

 warm season. 



Chosica is hot-arid with a ver}- low relative humidity from December 

 to May, and bracing cool-arid from June to November; with continual 

 clear sky practically throughout the year. 



Ica is hot-arid from December to Maj', hot-arid during days and 

 cool-subhumid during nights from June to November; without rain, 

 drizzle or mist, but with some cloudy weather in the afternoons dur- 

 ing August to October, aside from which the sky is practically clear 

 during the day throughout the year. 



All of the above localities are practically but little above sea level, 

 except Chosica which is 2,800 feet. Just a little farther back in the 

 foothills from Chosica and a little higher up lies a region of valleys 

 which are hot-humid from December to May with considerable rain 

 fall, and cool-arid from June to November with clear sky. The cli- 

 mate of the Ica cotton districts is markedlv distinct in character" 

 from that of all the immediately surrounding districts, clue to wide 

 rainless deserts on both sides of the valley, and approaches that of 

 Piura to such an extent that it is only in the Piura and Ica districts 

 that the native tree-cotton or pais variety can be profitably grown. 

 Ica is just nine degrees farther from the equator than Piura and its 

 nights during the cool season are colder, but on the other hand it 

 has less atmospheric humidity during the cool season than Piura. 



The weevil is quite certainly active at practically all times of the 

 year in the humid tropical Guayaquil district. It is known to be 

 practically inactive in the Piura region from December to May, which 

 season is truly arid in this region; and very active from June to No- 

 vember, which months show considerable atmospheric humidity. It 

 was known to be very active in March and April in the Casma region 

 in 1912. during a period of considerable atmospheric humidity. It 

 seems quite certain that it is more active during the warm season in 



