THE POTATO TUBER MOTH. 35 
During 1915 the parasitism averaged slightly over 1 per cent, as 
two individuals of DibracJiys boucheanus were reared, while 172 
specimens of Habrobracon joliannseni issued in the parasite cages. 
Three or four specimens were commonly noted in one host, and 
in the material reared under laboratory conditions a single hyper- 
parasite was rarely reared from one host. 
The following record shows the development of a fall generation: 
1913. 
October 27. — D. boucheanus parasitizing mature larvae of H. johannseni. 
November 8. — D. boucheanus larvae mature. 
November 14. — D. boucheanus larvae pupating. 
December 7. — 2 D. boucheanus adults issued. 
December 8. — 7 D. boucheanus adults issued. 
December 10. — 4 D. boucheanus adults issued. 
December 11. — 1 D. boucheanus adult issued. 
Life cycle 40 days at average mean temperature of 62° F. 
ZAGRAMMOSOMA FLAVOLINEATUM CWFD. 1 
During 1914 and 1915 Zagrammosoma flavolineatum (figs. 18, 19) 
wasnoticed issuing from cages containing some Phthorimaea operculella 
Fig. 19.— Zagrammosoma flavolineatum: Adult female, with lateral view of head. 
Much enlarged. (Original.) 
material. Efforts to rear it from the tuber moth were failures at first,, 
so numerous tuber-moth larvae were taken from leaf mines and placed 
on tubers so that there might be no danger of getting mixed material. 
No specimens of this parasite emerged in these cages, and it was 
supposed that it was issuing from some other host. 
i Chittenden No. 2230<*. 
