December, '10] pierce : weevil parasitism 451 



The length of the adult life is from 9 to 12 days. Adults died within 

 this period whether they were confined in a pill box with no food, or 

 under practically natural conditions. Thus far they have not been 

 seen feeding. It is possible that they feed on the surface tissue of the 

 orange or something else, but this has not been observed. But that 

 little food, if any, is taken in the adult stage seems likely, from the 

 fact that the adult life is the same whether confined without food or 

 in the 'presence of its probable food supply. 



The stages and abundance of Scutellista are very much dependent 

 upon the same conditions in the scale. Since the black scale is at the 

 height of egg laying in this section in June, it is then that Scutel- 

 lista larva or pupa will be most abundant. The period of greatest 

 emergence of adults is during July. Many fail to lay eggs at this 

 time because the scales are too young. It is necessary to find a scale 

 out of season with the ordinary brood which developed the Scutellista 

 in order for eggs to be deposited and the species perpetuated. 



The number of broods in a season is not well defined. One record 

 from egg to adult will serve to indicate the length of life and duration 

 of the different stages. Egg laid July 22; egg hatched July 27; 

 pupated August 12; adult emerged August 26; adult died September 

 4. The egg periocj is thus 5 days, larval 16, pupal 15, adult 9, or a 

 total of 45 days for the life cycle from the egg to the death of the adult. 

 If the scale were in the proper stage at the end of each generation 

 there would appear from 3 to 4 generations of the parasite during 

 the summer months, that is from May to September inclusive, and 

 there may be 2 or 3 generations also during the winter season, but on 

 account of the unfavorable conditions of the scale 4 or 5 will probably 

 be nearer the actual number. 



ON SOME PHASES OF PARASITISM DISPLAYED BY 

 ■ INSECT ENEMIES OF WEEVILS^ 



By W. DwiGHT Pierce, U. S. Bureau of Entoynology, Dallas, Tex. 



In a recent article Mr. W. F. Fiske^ has defined a certain phenome- 

 non as superparasitism, which has hitherto been recorded by the 

 present writer as accidental secondary parasitism .^ In defining this 



iPublished by permission of the Chief of the Bureau of Entomology. 



2W. F. Fiske, Superparasitism: An Important Factor in the Natural Control of 

 Insects. Joum. Econ. Ent., Vol. 3, pp. 88-97, February 15, 1910. 



'W. D. Pierce. Studies of Parasites of the Cotton Boll Weevil, U. S. Bur. Ent., 

 Bui. 73, p. 33, January 21, 1908. 



