PARASITES OF GIPSY-MOTH CATERPILLARS. 



191 



Fig. 29. — Limnerium disparis: Cocoon. 

 Enlarged. (Original.) 



that country than were either of the two species already mentioned in 

 Europe. In the winter of 1909-10 a few specimens were received 

 from Mr. Kuwana, together with the statement that it was common 

 as a parasite of the gipsy moth in Nagaoka, but not in Tokyo in 1908. 

 Attempts to import it in 1910 were unsuccessful, and it is with the 

 hope of confirming its importance, at least locally, and discovering 

 some method of transplanting it to America, should such confirmation 

 come about, that the investigations are 

 undertaken in Japan in the year 1911. 



Limnerium disparis Vier. 



This interesting parasite was first re- 

 ceived in June, 1907, in a shipment of 

 small gipsy-moth caterpillars from Kief, 

 Russia. A total of 18 of its peculiar 

 cocoons (iig. 29) was received in June 

 and July of that year in boxes which contained only a relatively 

 small number of caterpillars when sent, and its importance as a 

 parasite appeared to be considerable. It seemed probable that the 

 larvae spinning them had issued from caterpillars in the fourth and 

 fifth stages. 



The cocoons usually approach more nearly the spherical than that 

 used as the type for the drawing. The walls are thin, but so dense 



as not only to be impervious 

 to moisture, but to prevent 

 the drying of the meconial dis- 

 charge for months. 



None of the cocoons was 

 hatched on receipt. A single 

 male adult (fig. 30) issued from 

 one of these cocoons in August. 

 No more adults appearing, 

 some of the cocoons were 

 opened from time to time dur- 

 ing the fall and found to con- 

 tain still living adults. Since 

 it is known that several of the 

 native species which spin sim- 

 ilar cocoons actually do hiber- 

 nate as adults within the cocoon, it is reasonable to suppose that the 

 same is true of this. 



No adults were reared, however, and their failure to emerge appears 

 to be due to the drying during the winter of the semiliquid meconial 

 discharge which effectually glued the adults to the sides of the cocoon 

 and prevented their further movement. 



Fig. 30. 



-Limnerium disparis: Adult male. Much en- 

 larged. (Original.) 



