430 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 5 



was very astonishing, as this insect had been looked upon as an egg 

 parasite. However, it confirmed the opinion of the senior writer 

 that, inasmuch as the adult was twice as large as the host egg, it could 

 not develop to maturity in the egg. It seems that, unknown to the 

 writers, Mr, W. F. Fiske of the Bureau of Entomology had held the 

 same view, for he suggested to Doctor Chittenden last fall that, as the 

 parasite was so much larger than the egg of the asparagus beetle, it 

 could not possibly breed from it, but must come from a much larger 

 beetle. He thought that a species of Trirhahda which feeds on Soli- 

 dago sp. was most likely to be the true host of this insect and that its 

 habit of feeding on eggs of the asparagus beetle was an acquired one. 

 Mr. Fiske, however, also missed the connection in the curious life 

 history of this insect, possibly because he had not observed it in the 

 field. 



As true oviposition had been noted in the eggs of the asparagus 

 beetle, and as this parasite refused to feed on the eggs of the potato 

 beetle {Leptinotarsa 10-lineata) and of the elm leaf -beetle {Galerucella 

 luteola), even when confined with nothing else, the senior author held 

 to the view that the asparagus beetle, in some stage, must be the true 

 host. Dissection of the eggs of the host, by the junior author, revealed 

 the eggs of the parasite and it appears as if this insect must develop 

 in the larva of the beetle. 



On June 10, when this insect was first observed, the senior author 

 collected a number of nearly mature beetle larvse and brought them 

 into the laboratory. These entered the ground on June 21 and formed 

 pupal cells. These cells were dug up on July 2 and examined. Many 

 contained the pupae of the beetle, but one was found to be packed 

 with six white parasitic larvse and nothing remained of the host but 

 the black larval skin. These larvse were about mature and some days 

 later changed to pupae, but all died in that stage. Thus, for a second 

 time this life-history problem failed of being solved, as it was not 

 proven that the insect that parasitized the egg of the host belonged to 

 the same species as the larvae that developed in the host larvse. The 

 writers, nevertheless, felt encouraged to continue the investigation. 



About July 10 another lot of asparagus-beetle larvae was collected 

 by the junior author and placed in large vials in the laboratory. When 

 examined July 24, many had changed to adults of the asparagus beetle, 

 but in one vial there were three pupae of a parasite similar to those 

 previously observed. On August 1 and 2 the adult parasites emerged 

 and were identified by Mr, J, C, Crawford as Tetrastichus asparagi. 



During the last half of July, after an absence of several weeks, the 

 adult of this parasite was again discovered in the asparagus fields 

 feeding and ovipositing in the eggs of the beetle. At that time the 



