36 



BULLETIN 427, U, S. DEPAKTMENT OF AGRICULTURE. 



Finally a parasite pupa was noted in a leaf mine "witb. the remains of 

 a tuber-moth larva. When the adult issued it proved to be Zagrammo- 

 soma jiavolineatum. More experiments were carried on, using only 

 material where the tuber-moth larvae occurred as leaf-miners and 

 were less than half grown. The parasite was seen to oviposit in 

 these larv93, and it was successfully reared through to the adult. 



This parasite thus far has not proved to be of much importance, 

 and seems unpromising, as the adult is so slow and deliberate in its 

 movements that a tuber-moth larva in a large mine can move about 

 and often escape the ovipositor of the parasite. 



The following record gives the length of its life cycle: 



1915. 

 August 17. 

 August 29.- 

 August 30. 

 August 31. 



■Zagrammosoma Jiavolineatum ovipositing in tuber-moth larva. 



1 Zagrammosoma Jiavolineatum adult issued. (Male.) 



2 Zagrammosoma Jiavolineatum adults issued. (Males.) 

 •1 Zagrammosoma Jiavolineatum adult issued. (Male.) 



September 1. — 1 Zagrammosoma Jiavolineatum adult issued. (Female.) 

 September 2. — 2 Zagrammosoma Jiavolineatum adults issued. (Male and female.) 

 Life cycle 13 days at average mean temperature of 75°F. 



SYMPIESIS STIGMATIPENNIS GIRAULT.^ 



During 1914 and 1915 tuber-moth material collected at Pasadena 

 during late fall gave great numbers of a small parasite, the male of 



which (fig. 20) had 

 ¥\ <r ■¥ r .<^ branched antennae. 



At about the same 

 time an examination 

 of mines on potato 

 leaves often showed 

 a parasitic larva (fig. 

 21) feeding extern- 

 ally on a partially 

 grown larva of the 

 tuber moth. When 

 these were reared 

 they proved identi- 

 cal with those issuing 

 in the parasite cages. 

 The parasite was 

 reared with ease in 

 the laboratory, and 

 it oviposited readily in leaf-mining tuber-moth larvse when half grown 

 or sHghtly smaller. The host is soon killed and within a short time 

 becomes semiliquid, and the development of the larva is very rapid. 

 When matin-e (fig. 22) it crawls into a corner of the mine and, without 

 spinning a cocoon, pupates. 



Tig. 20. — Sympiesis stigmatipennis: Male. Much enlarged. (Original.) 



1 Cluttenden No. 2230''2. 



