COTTON BOLL WEEVIL IK THE MISSISSIPPI VALLEY. 3 



Thus it is seen that these studies embrace a wide range of time 

 and conditions. In fact, the conditions of humidity, rainfall, tem- 

 perature, altitude, soil, etc., include practically all extremes found 

 in the cotton belt. 



The various breeding series of 1914 and 1915 were conducted in a 

 large insectary located at the Delta Laboratory, Delta, La. (fig. 1). 

 This was provided with screen sides to furnish free air circulation, 

 and the curtains were so arranged that the direct sunshine did not 

 reach any of the breeding cages. Practically all of the breeding 



Fig. 1.— liiSLTku y at llii' LiboiMtur) ,iL J> lia, L i , fm btuilic^ ou tli'' boll \\eL\ j1. (.Oiitiiiial ) 



work was done in glass tumblers partially filled with moist sand and 

 covered with a double thickness of cheesecloth. 



LONGEVITY OF ADULT WEEVILS. 



A considerable number of observations were made on the adult 

 longevity on different foods. The data secured are separated by 

 seasons. 



SEASONS OF 1913 AND 1914. 



Table I gives the observations made during the seasons of' 1913 

 and 1914. The maximum record of longevity in 1914 was made by 

 a first-generation female fed on cotton squares. This female emerged 

 July 13 and died October 28, with a total life of 107 days. The 

 maximum length of life of male weevils fed on cotton squares was 

 100 days; this individual emerging July 14 and dying October 22. 

 The average longevity was 9.8 days on cotton leaves, 10.5 days on 

 cotton bolls, and 46.3 days on cotton squares. 



