THE PAEASITE SEASONS. 65 



pecan, collected April 2, 1907, at Victoria, Tex., and was reared June 

 5, 1907, from material collected May 4 at Dallas. 



SigalpJius curculionis was reared in considerable numbers between 

 April 28 and May 7, 1907, from Conotraclielus nenuphar in plums 

 gathered at Texarkana, Ark., March 26; and between April 29 and 

 May 17, 1907, from Conotraclielus elegans in galls of Phylloxera devas- 

 tatrix on pecan, collected at Victoria, Tex., April 2; also between June 

 5 and 14, 1907, from the same species in material collected at Dallas, 

 Tex., May 4. 



Ceramhycohius cyaniceps was studied very carefully at Victoria, 

 Tex., by Mr. J. D. Mitchell during the winter of 1909-10 as an 

 enemy of Trichoharis texana in stems of Solanum rostratum, and of 

 Lixus scrohicoUis in stems of Ambrosia trifida. Mr. T. T. Holloway 

 conducted experiments in longevity by feeding sugared water to the 

 parasites. Emergence began, in the lots of Trichobaris, on February 

 1 and continued until April 8. The last parasite lived until May 31. 

 The total period of activity was 119 days and the average period 

 lasted from March 11 to April 1. The longest record of longevity 

 was 71 days and the average 21 days. Emei^ence began from the 

 lots of Lixus on March 2 and continued until March 24. The last 

 parasite lived until May 11. The total period of activity was 70 

 days and the average period was between March 13 and April 4. 

 The longest record of longevity was 67 days and the average 22. 



Eurytoma tylodermatis was reared from the same lots and treated 

 in the same manner. Emergence began from the lots of Trichobaris 

 on February 3 and continued until March 21. The last parasite 

 lived until April 30. The total period of activity was 86 days and 

 the average period was between March 10 and March 30. The longest 

 record of longevity was 42 days, and the average 20 days. Emergence 

 began from the lots of Lixus on February 22 and lasted until April 17. 

 The last parasite lived until June 1. The total period of activity 

 was 99 days and the average period lasted from March 16 to April 11. 

 The longest record of longevity was 79 days and the average 26 days. 



III. THE SUMMER SEASON. 



Tlie first boll-weevil parasites of the year are reared late in May or 

 early in June in southern Texas, but in a very short time squares are 

 forming all over the entire cotton belt and parasites may be found 

 everywhere in smaU numbers as the summer progresses. The per- 

 centage of parasitism increases rapidly and generally becomes very 

 high after August 1. Most of the important parasites may also be 

 found on their normal summer hosts. 

 16844°— Bull. 100—12 5 



