312 Journal of Agricultural Research voi. iv, No. 4 



pears to be of greater value as an egg destroyer than as a parasite devel- 

 oping within the host. 



Mr. C. W. Prescott, of Concord, Mass., recently wrote that on May 23, 

 1909, he had noticed the parasite in the field feeding on the host eggs, 

 and that on the day of writing he had attempted to find "slugs" or 

 larv^ae, but could find neither slug nor egg except those absolutely dry, in 

 a field of 5 acres. 



During the season of 1912, the field of asparagus at Aquebogue, N. Y., 

 where this insect was found, received no treatment for the beetles, yet 

 these were so scarce that no damage resulted. Previous to this, according 

 to the owner, the field had been sprayed each year to prevent serious 

 injury. 



Without doubt this parasite was to a large degree responsible for the 

 scarcity of the asparagus beetles. Certain other factors may have 

 assisted, but there is little doubt that the parasites were the most 

 important factors in preventing damage. 



SUMMARY 



Previous to the time that Tetrasiichus asparagi was believed to be an 

 egg parasite, its life history had never been worked out. As the parasite 

 had been observed ovipositing in the host egg, it was supposed that it 

 developed in the egg. During the investigation of the life history it was 

 discovered that this insect presented one of those peculiar instances where 

 oviposition in the host's eggs and retarded development of the parasite 

 permitted the host to develop. In this case the following takes place : 



The parasite deposits her eggs in the egg of the asparagus beetle; the 

 beetle egg hatches; its larv^a feeds to maturity and entering the soil 

 forms a pupal cell, but does not pupate. The parasites have by this 

 time totally consumed the larva and emerge from it into the cell the 

 larva has constructed, where they pupate and later emerge as adults. 



Since the parasitic larva passes the winter in the soil in the pupal cell 

 of its host, it would appear that the parasite might easily be transported 

 from one place to another in the soil which might surround a shipment 



of asparagus roots. 



LITERATURE CITED 

 (i) Crawford, J. C. 



1909. Two new species of the genus Tetrastichus (Hymenoptera, Eulophidae). 

 In Proc. Ent. Soc. Wash., v. 11, no. 3, p. 150. 



Technical description of adult female of Tetrastichus asparagi, n. sp., from Amherst, 

 Mass. 



(2) Fernald, H. T. 



1909. A parasite of the asparagus beetle. Mass. Agr. Exp. Sta. Circ. 23, 2 p. 



Brief account of discovery and oviposition and observations on some of the habits of 

 the adult. 



(3) 



1909. A parasite on the asparagus beetle. 7n Jour. Econ. Ent., v. 2, no. 4, p. 

 278-279. 

 Substantially the same as preceding article. 



