143 
The Furple Scale of the Orange in Montserrat. 
The Icerya insect has not reappeared in our lime orchards which is the reason why 
Mr. Hamilton has not written to you for the ladybirds. We are, however, overrun 
with the Purple Scale (Mytilaspis citricola) and our emulsions do not seem to pene- 
trate the egg covers. It is impossible to keep up a continuous succession of striving 
to kill each brood of insects as it hatches out, and the spraying does not therefore 
seem to meet the difficulty. My object in writing to you is to ask whether you know 
of any parasite which we could introduce to prey upon the Purple Scale as the lady- 
bird does upon the Icerya. These natural antidotes seem to be the best, if only one 
can get hold of them.—[Joseph Sturge, England, July 4, 1891. 
REPLY.—No satisfactory enemy of the Purple Scale is known to this country. 
Very few insects seem to attack it, and it will not be worth while to attempt to im- 
port any of these into Montserrat. I do not know how the climate of Montserrat 
differs from that of the orange growing regions of Florida, but in the latter State the 
kerosene emulsion spray is only to be applied during the time of year when the young 
lice are hatching. The periods are rather irregular, and hatching is more or less 
continuous throughout the year. As a rule, however, in Florida, new generations 
begin in March, June, and September, and at the end of each of these months the 
application of insecticides meets with the greatest success. A similar state of affairs 
will, probably, upon close examination, be found in Montserrat.—[July 17, 1891.] 
Notes on Buffalo Gnats. 
During the winter of 1890 we had the water in Red River and its swamps higher 
than ever known before in its history, just the condition most favorable for the 
breeding of the Buftalo Gnat, yet we had very few of them as compared with pre- 
ceding springs. I account for this apparent paradox by stating that the winter 
of 1890 was such a mild one that the gnats kept on hatching out during the months 
of December, January, February, and March. They made their appearance so grad- 
-ually as not to give much trouble at the regular time, which is the latter part of 
February and during March. 
We also had comparatively few of them last spring, although the water conditions 
were favorable during the winter and spring months. I account for this from the 
fact that during last fall the water in our bayous became so low as almost to cease 
flowing. No current at all could be noticed in the vicinity of the raft, which is the 
home of their larve. I think that all the larve in these regions must have died, 
owing to the stagnant water, and that the gnats that we did have came from larve 
that were brought down from upper Red River when that stream rose during the 
winter. If this is a fact, then we can predict that we will not be troubled with 
many of them the coming spring, because Red River is at present about as low as it 
was at this time last year. No current can be noted now about on rafts, and I hope 
that the larve are all dead. 
I took a trip along the region of rafts a few days ago, and found that owing to the 
very low stage of water quite a number of fish were dying, and millions of shrimps 
were putrefying on the banks of the streams, causing a great stench for miles. I 
think that every shrimp in this part of Bayou Pierre must be dead. These shrimp 
are dead by the barrelful in a bayou where there is still some current. 
The water in Bayou Pierre where they have died in such numbers is from 10 to 20 
feet deep. Now, if the lack of current can cause the death of shrimps in such vast 
numbers, why should the larve of the Buffalo Gnat not perish from the same cause? 
Can you tell me why the shrimp die in this way? They do not need the current to 
bring them their food as do the Buffalo-gnat larve.—[G. A. Frierson, Louisiana, 
‘September 27, 1891. 
REPLY.— * * * Weare very much obliged to you for this information regard- 
ing Buffalo Gnat matters in your vicinity. We are pleased that you have been so 
fortunate the past two seasons and are of the opinion that your explanations are 
