Dec, '12] RUSSELL AND JOHNSTON: BIOLOGY OF TETRASTICHUS 429 



THE LIFE HISTORY OF TETRASTICHUS ASPARAGI CRAWF.i 



By H. M. Russell and F. A. Johnston, Bureau of Entomology, United Stales 

 Deparlmenl of Agriculture 



Tetrastichus asparagi was first recorded in July, 1909, as an enemy 

 of the common asparagus beetle {Crioceris asparagi Linn.), by Dr. 

 H. T. Fernald,^ who published another short article on the same insect 

 in August of that year.^ In these papers Doctor Fernald described 

 the habits of the female in ovipositing in the egg of the host and stated 

 that it appeared as if this insect would be an efficient egg parasite of 

 the asparagus beetle. Unfortunately, through press of other matters, 

 he could not devote sufficient time to this insect so that he did not rear 

 the adult, and so failed to observe the strange life cycle, and the 

 equally interesting feeding habits of the mature insect. This species 

 was described bj^ Mr. J. C. Crawford, of the United States National 

 Museum, in October, ,1909.^ 



While the writers were located at Riverhead, Long Island, N. Y., 

 during the summer of 1912, this insect was observed in large numbers. 

 The observations here recorded were made on its life history and habits 

 at that time. The junior writer by his careful manipulation was 

 successful in carrying this insect through its complete life cycle. 



On June 10 the writers were inspecting a field of asparagus at Aquo- 

 bogue, that was being cut for market. This field had a few uncut 

 rows that had been left as a trap to attract the asparagus beetles and 

 on these rows the asparagus beetle was verj'- abundant and the eggs 

 M^ere found on the plants in large numbers. Associated with these 

 beetles in noticeable numbers were the adults of this parasite, often 

 from five to, seven occurring on a single stalk. Observation revealed 

 that these were ovipositing repeatedly in the eggs of the asparagus 

 beetle and at the same time destroying many of the eggs by feeding 

 on them. This feeding was so extensive that out of 2,097 eggs counted 

 on 28 stalks of asparagus, 1,495 had been destroyed. 



A number of adults of this parasite were brought into the laboratory 

 and allowed to oviposit in the -eggs of the asparagus beetle. Instead 

 of the adult parasite emerging from these eggs, however, the larvae of 

 the beetle came out, but died from lack of tender food. This result 



» Published with the permission of the Chief of the Bureau of Entomology. 



2 A parasite of the Asparagus Beetle, Cir. 23, Mass. Agr. Exp. Sta. (1909). 



3 A Parasite of the Asparagus Beetle, Journal of Economic Entomology, vol. 2, pp. 

 278-279 (1909). 



' Tetrastichus asparagi n. sp. Proc. Ent. Soc. Wash., vol. 11, p. 150 (1909). 



