19 



was received no traces of the plague locust were left ami a further 

 attempt to secure more of their parasites had to be abandoned. These 

 fly-papas must have hatched alter leaving San Francisco, as up to 

 the time of their arrival there they had been kept on ice. By some 

 mistake they were sent to Los Angeles first, and from there, no doubt, 

 over the southern route to Washington, as they would not have come 

 out over the central route in January. 



I I.l I ISLANDS. 



On April 28, 1892, I left Sydney for a trip to the Fiji Islands, and ar- 

 rived at New Caledonia on May 4. Here a few hours could be spared 

 in search of insects, to which I refer elsewhere. The most interesting 

 thing found here were dipterous parasites upon a large species of grass- 

 hopper, Pachytylns micratorioides Reich., according to Mr. Bruner, who 

 informed me that it is closely related to the migratory species of Europe, 

 Asia, and Africa. These latter were but sparingly met with in the dry 

 hillsides near Neumea, yet the ground was noticed to be full of dead 

 and empty individuals. In living specimens examined dipterous larva' 

 were found, and from these two species of flies were bred in course of 

 time. Upon some of the locusts, as well as upon their larvae and pupa?, 

 dipterous eggs could be found. Upon one of the pupa? eight of these 

 were found upon the hind legs, the wings, and pronotum. The locusts 

 are always more or less numerous upon this island, with its bare hills, 

 and in consequence sugar-growing had to be abandoned, as they devour 

 most of the young cane. About a week previous to my arrival some 8 

 tons of the locusts were collected in traps, such as are in use in Algiers. 

 I met with large numbers of them along the road some 8 miles from the 

 city, at about 3 p. m. For a half mile in length the road was com- 

 pletely covered with the locusts, which came from the adjoining loAvand 

 swampy land, which supplied abundance of food, and the air was cloudy 

 with them to a height of some 300 feet. Their flight appeared to be in 

 an easterly direction. Xo doubt they left their feeding ground to re- 

 pair to the bare hills to deposit their eggs, or probably, to evade the 

 dipterous parasites which must have been present in countless num- 

 bers, as was noticed on the hills near Neumea, where within a space of 

 some 20 square yards some two hundred and fifty Sareophaga were col- 

 lected within less than one hour's time. The flies were sitting around 

 the plants at rest, or were, as it appeared, in search of the locusts near 

 the ground where these were hidden. With the exception of the nu- 

 merous dead and a few living locusts no other insects were present upon 

 which these Hies could breed, and the occasional Lepidopterous larva? 

 met with were all in a perfectly healthy condition. I concluded 

 that the countless number of Tachina present could only have devel- 

 oped within the grasshoppers, and the numerous dead and eaten out 

 specimens were proof to me that these Hies had done the work. I col- 

 lected these Hies with a view to introducing them, if possible, upon 



