417 
We have recently received an interesting letter from Mr. William H. 
Crane, of Steele City, Nebr., in which he tells of a large prismatic- 
tinted black wasp locally known as the grave-digger which preys upon 
a green katydid. This wasp, we are informed, also has an enemy which 
pursues it as relentlessly as it does the katydid. One day our corre- 
spondent observed a wasp with a katydid and seemingly annoyed by 
something - . Soon two flies not much larger than house flies, "with 
wings that stood out from their bodies like a dragon fly." were seen. 
Their motions were so swift that they were lost sight of repeatedly, but 
they had a habit of " standing still on the wing watching for an oppor- 
tunity to deposit an egg on the wasp or his prey if he relinquished his 
vigils for an instant; but the wasp interrupted them, fluffing up his 
wings like a hen protecting her brood. Then one would approach from 
the rear and endeavor to deposit an egg at the base of the wasp's wing or 
on the back of its head. Once a fly succeeded in placing an egg on its 
victim's head, but it was promptly clawed off' by the wasp." The fly in 
question is doubtless one of the Tachina flies, but we know of no record 
of any of these insects being parasitic on adult digger wasps. 
MIGRATION OF THE GREAT PLAINS CRICKET. 
The same correspondent mentioned in the preceding note writes us 
that he has seen an insect which he calls the army cricket marching in 
innumerable numbers, destroying everything green in their path. A 
swarm was seen on the Bear River on the boundary of Utah and Idaho. 
It was 10 miles in length and a quarter of a mile in width. " In front 
of this army." writes our correspondent, --the landscape was green, 
behind a brown waste. Large streams deflected their course, but small 
creeks they crossed with impunity, jumping in and swimming. They 
climbed the willows that grew over the brook and by their combined 
weight bent them over, thus bridging the stream. After the crickets 
had crossed, the willows appeared as if scorched by fire. These streams 
were filled with trout, and as the vanguard of the army plumped into 
the water they were pounced upon by the hungry fish, but when the 
tens of thousands followed, so as to almost dam the current, the gorged 
trout sought the deepest pools, feeling no doubt like the Hebrews after 
their feast of quails." 
The insect referred to is undoubtedly the Great Plains cricket. Ana- 
brus simplex* a species to which we have frequently had occasion to 
refer in past issues of the publications of this division. 
NOTE ON THE CHICKEN TICK (ARGAS AMERICANTJS PACK). 
During the kitter part of December of the past year we received 
specimens of the above-mentioned insect from Mr. 0. H. T. Townsend. 
who found it infesting chickens at San Diego, Tex. It will be 
remembered that we published, on pages -*i7 and 348 of volume v of 
INSECT Life, some interesting correspondence on this species and its 
