148 JOURNAL OF ECONOMIC ENTOMOLOGY \Yo\. 9 



other place where they can breed. They would in this case have to 

 jfly continuously across the lake. 



Mr. T. J. Headlee : It was noted in England where flies had come 

 from five miles away. 



President Glenn AV. Herrick: The next paper will be b}" ]\Ir. 

 Joseph H. Merrill. 



LIFE-HISTORY AND HABITS OF TWO NEW NEMATODES 

 PARASITIC ON INSECTS 



By Joseph H. Merrill, Manhattan, Kans. 

 (Withdrawn for publication elsewhere) 



President Glenn W. Herrick: It is interesting to find that there 

 are some nematode forms that seem to be of some use in life. 



I did not understand Mr. Merrill to say whether they actually killed 

 the insects. 



Mr. J. H. Merrill: A tent was placed around the trunk of an 

 elm tree so that all emerging insects might be secured for breeding 

 purposes. There were 121 Saperdn fridentata which emerged from 

 this tree and were placed in breeding cages, but in no instance did any 

 of these insects deposit eggs. Not only was the vitality of the insects 

 lowered but their natural functions were so interfered with that eggs 

 did not even start to develop within their bodies. The death rate, due 

 to nematode parasitism, was 100 per cent. Several experiments were 

 carried on by placing termites in soil known to contain nematodes. 

 In twelve days all of the termites had died, due to this nematode 

 parasitism. 



Mr. Don C. Mote: I would like to inquire whether these nema- 

 todes are truly parasitic. I take it from the paper that j\Ir. ]\Ierrill 

 was able to rear them from the egg to the adult stage in cultures. This 

 fact would seem to indicate that they are not necessarily dependent 

 upon taking up their abode in the insects' intestines for their develop- 

 ment. Generalh' nematode parasites attain a certain point in this 

 development outside the host beyond which they cannot go unless they 

 reach their normal habitat within their host. 



Mr. J. H. Merrill: These nematodes were found to be parasitic 

 on Saperda tridentata and Leucotermes lucifugus. The nematodes found 

 in S. tridentata were fed in cultures on the macerated bodies of insects, 

 while those found in the termites were fed exclusively on termites as 

 we could easily secure a plentiful supply of these insects. 



Mr. Don C. Mote: At what time during the developmental stage 

 did infestation occur? 



