34 
Prior to ruy arrival in the valley the citizens of Grand Junction sent to the Col- 
orado oil region at Florence and secured a 1,000-gallon tank of crude petroleum oil 
for use in destroying the 'hoppers. This, I ascertained, it was intended to use by pour- 
ing it into the irrigating ditches, and in that manner spread it over the country. In 
my address I insisted that this would only he wasting the material and destroying 
the vegetation wherever the oil reached, and that the 'hoppers would be mostly all 
left unhurt. We tried the oil in the "hopper d<>z< j rs " and were surprised at the 
results. It worked much better than the refined oil does, and its cost was so very 
much less, being only 4 cents per gallon delivered at Grand Junction. 
There are several species of locust concerned in these injuries in and about Grand 
Junction. I found Mdanoplus atlanis, M. bivittatus, and M. differentialis. There were 
also several other species of locusts that were very numerous in the valley. One of 
these was what appears to be an undescribed species of Pezotettix, bearing some resem- 
blance to 21. turnbulli, only with very short and narrow tegmina. Like that insect, 
this Pezotettix also seems to confine its attention almost entirely to the various spe- 
cies of Chenopodiacesej of which there are quite a number of forms common to the 
region. It is especially fond of the grease-wood (Sarcobates rermicularis). Pecu- 
liarly enough was the fact that on my arrival in the valley all the plans that were 
then under way were for the destruction of this "native" species of Pezotettix that 
did none or very little of the injury that had thus far occurred in the region. 
If the instructions which I gave and insisted upon being carried out be followed 
by this time the valley could be practically free from this pest. I would also state 
that aside from the price paid for labor the cost for this extermination would not 
be above a couple of thousand dollars; while, if nothing be done, there are or were 
hoppers enough in the valley to destroy a half million dollars' worth of crops and 
trees. Last year the pest might have been handled for even less than this amount, 
and the $200,000 and more of injury that was sustained might have been saved. I 
even went so far in my remarks as to state that if one-tenth of the amount lost on 
the one orchard referred to above had been properly expended at the right time last 
year there would have been no need of worry and fighting the present year, and 
nearly all the loss sustained might have been avoided. — [L. Brunei', Nebraska. July 
10, 1893. 
A Peculiar Gad-fly. 
I inclose sample of a species of Tabanus that is very annoying to stock after sun- 
down. They do not appear during the day, except rarely on very dark days, but in 
June and the early part of July they swarm upon cattle and horses after sunset and 
render them well-nigh frantic in their efforts to escape. As soon as darkness comes 
on, or say about half-past eight now, all the flies disappear. One hour each evening- 
is about the extent of their feeding time, and as they all come at once they make 
lively times in the cowyard. Milk cows, etc., can be protected by stabling in dark 
place every evening, but this is impracticable with herds in pasture. — [G. M. Dodge r 
Missouri, June 18, 1893. 
Reply. — * * * Your account of the habits of the species which you send — 
Tabanus tectus — is very interesting. Can you not ascertain the breeding habits? 
You have a good chance to try the effect of fish oil and other repellants which act 
fairly well against the Horn Fly. I should be interested to know whether they will 
keep off the gadflies.— [June 21, 1893. 
Second letter. — Tabanus tectus is now nearly gone. I got one specimen to-night 
at about 8 p. m., considerably worn. Saw no others. It usually lasts about one 
month, and is single brooded. I did not learn its breeding habits. 
As advised in your letter I tried fish oil as a preventive. Mixed it with bacon fat 
and put it on in the evening, when the flies were most plenty, which was about 8 
o'clock. It seemed to have no effect. The flies would alight and draw blood where 
the hair was shining with grease. There were but one or two cows in the herd that 
