JOURNAL 



Jlf\a "Sinvk ^nj^omologiral %m'it'^^. 



Vol. XV. SEPTEMBER, 1907. No. 3. 



Class I, HEX APOD A. 



Order I, HYMENOPTERA. 



TRICHOGRAMMA PRETIOSA RILEY. MISCEL- 

 LANEOUS HABITS OF THE ADULT, WITH 

 A LIST OF HOSTS. 



Bv A. Arsene Girault, 

 Washington, D. C. 



The following is a conclusion of the publication of observations 

 made on this egg-parasite during the Cotton BoUworm Investigations 

 in Texas in 1904 by the National Bureau of Entomology. The more 

 important of these have already been published, or presented for publi- 

 cation, and this brief paper records especially those details of its life- 

 history which are of minor consideration or of interest solely from the 

 biological standpoint. The observations were made at Paris, Texas, 

 latitude 33° 45', and the host was Heliothis obsoleta Fabricius, the 

 common boUworm of cotton. 



Emergence. — The little parasites issue from the host eggs as adults 

 through one or several holes cut by their jaws generally in the upper 

 side of the egg. The hole is usually rounded in outline, but with 

 jagged edges. Quoting from a general note made in 1904: "Out 

 of 36 cases of emergence, 32 were from single holes in various parts 

 of the host ^^^^ ; the remaining 4 were from 2 holes in the host. In 

 the latter cases, in 2 hosts, there were 2 large, equal, round holes, side 

 by side in the upper end ; in the third, 2 unequal round holes, one 

 on each and opposite sides of the host, and in the fourth case, exit 

 was made through a small round hole at apex and a large jagged rent 



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