﻿THE CATTLE GEUBS OR OX WARBLES 



73 



LONGEVITY OF ADULTS 



Owing to the fact that the adults of Hypoderma are very rest- 

 less when in captivity and since there seems to be no means of 

 keeping records of specimens in nature, the writers' observations 

 on the length of life of the adults may give erroneous ideas. The 

 longevity of reared adults of //. lineatum is shown in Table 10. It 

 ranged from 1 to 25 days and averaged somewhat longer for males 

 than for females. The markedly greater longevity observed among 

 about 50 adults reared in the laboratory during the spring of 192-1 

 than had been noted previously indicates clearly the probability 

 that certain individuals which emerge prior to periods of uniformly 

 cool weather may live for a considerable time. The specimens re- 

 ferred to were hastened in their emergence by being kept in a 

 warmed room. After emergence the adults were transferred to 

 lantern-globe cages and kept in an unheated room. The tempera- 

 tures given in Table 10 for these records for 1924 were those re- 

 corded in a standard weather shelter out of doors, and hence un- 

 doubtedly show a much greater range of temperature than was 

 actually experienced. There is no question but that in nature the 

 flies would seek the sunshine and warmer places which would stimu- 

 late activity, and thus we should not expect to find such long periods 

 of existence as those referred to above. The writers' observations 

 in the field also bear out this assumption. It seems certain that 

 when the weather is warm and the adults are active their lives are 

 uniformly very short. 



Table 10. — Adult longevity of Hypoderma lineatum, at Dallas, Tex. 



Date 



adults 



emerged 



Num 



bar 



of 



males 



Num 

 ber 

 of 

 fe- 

 males 



Record of death 





Temperature 



Lon- 

 gevity 





Min. 



Max. 



Aver- 

 age 



Days 



7 



°F. 

 48.0 



°F. 

 83.5 



"F. 

 67.6 



3 



54.0 



82.0 



69.0 



1 to 3 



61.5 



97.9 



80.2 



1 to 7 



38.0 



88.0 



61.7 



1 to 2 



39.5 



88.0 



66.3 



2 to 3 

 2 to 3 



38.0 

 38.0 



97.5 

 87.0 



66.2 

 58.2 



2 

 3 to 8 



38.5 

 33.7 



87.0 

 90.0 



56.2 

 60.9 



2 to 6 



33.7 



90.0 



56.5 



7 to 9 



30. 



87.0 



63.4 



4 to 9 



3(1.0 



H7.0 



64.0 



1 to 8 



51.0 



87.0 



71.7 



Remarks 



1915 

 Apr. 12 



Apr. 19 



1916 

 Mar. 20 



Mar. 22 



Mar. 27 



1918 

 Feb. 25 

 Feb. 26 



Feb. 27 

 Mar. 11 



Mar. 13 



1921 

 Mar. 7 



Mar 8 



Mar. 12 



1915 

 Apr. 19, a.m 



Apr. 22, p.m- 



1916 

 Mar. 21, 2 9 ; Mar. 22, 1 9 ; 



Mar. 23, 1 cf. 

 Mar. 23, 1 9 ; Mar. 24, Icf , 



2 9; Mar. 25, Zd": 59; 



Mar. 27, 29,1 cf; Mar. 



28, 2c?'; Mar. 29, Scf. 

 Mar. 28,1 9;Mar.29, 2 cf , 



1 9. 



1918 

 Feb. 27, 1 cT; Feb. 28,1c?- 

 Feb. 28, 1 cf , 3 9 ; Mar.l, 



2 9. 



Mar.l 



Mar. 14, 2 cf, 1 9; Mar. 



19, 1 cf . 

 Mar. 15, 1 9 ; Mar. 19, 2 cf 



1921 

 Mar. 14, 2 cf; Mar. 15,4 c?, 



1 9; Mar. 16, 2 cf. 

 Mar. 12, 1 9 ; Mar. 13, 1 cf ; 



Mar. 15, Id'; Mar. 16, 



4 rf'; Mar. i7,2d'. 

 Mar. 1.3, 1 d'; Mar. 1.5, 1 <f; 



Mar. 18, 7 d', 8 9 ; Mar. 



20,1c?'. 



In cage 1 foot by 1 foot 

 by 1 foot, with leaves. 

 In small cage, with 

 leaves. 



In cage 1 foot by 1 foot 

 by 1 foot in sun. 



In small and large 

 cages and on cow. 



Do. 



In laboratory. 

 Do. 



Do. 



In 1-inch tubes (9 de- 

 posited) . 



In 1-inch tubes with 

 leaves. 



In liintern globes with 

 leaves. 



In cage 1 foot by 1 foot 

 by 1 foot, with loaves. 



