THE POTATO TUBER MOTH, 35 



During 1915 the parasitism averaged slightly over 1 per cent, as 

 two individuals of Dihracliys houcJieanus were reared, while 172 

 specimens of Hahrohracon johannseni issued in the parasite cages. 



Three or fom' 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 larvse of H. johannseni. 

 November 8. — D. boucheanus larvse mature. 

 November 14.^ — D. bouchsanus larvse pupating. 

 December 7. — 2 D. boucheanus adults issued. 

 December 8. — 7 D. boucJieanus 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.^ 



During 1914 and 1915 Zagrammosoma flavoUneatum (figs. 18, 19) 

 wasnoticed issuing from cages containing some Phthorimaea operculella 



Fig. W.—Zayrammo.wma flavolinmlum: Adull, female, with lateral view of head. 

 Much enlarged. (Original.) 



material, EfTorts to rear it from the tuber molJi were failures at first, 

 -o inimcrous tuber-mot]i Lirvir; wen; tak<'ii from leaf mines and placed 

 Mil tubers so that tliere migJii be no danger of getting niixiul material. 

 So specimens of Ibis ])anisil(^ emerged in these cages, and it was 

 supposed that it was issuing from some other host. 



« Chittenden No. 2230»». 



