143 



The Purple Scale of the Orange in Montserrat. 



The Icerya insect has uot reappeared iu our lime orchar<l.s whidi is the reason why 

 Mr. Hamilton has not written to you lor the la(lyl)ir(ls. We are, however, overrun 

 with the Purple Scale (MtftilaHpis ritricola) and our emulsions <lo not seem to pene- 

 trate the eg<5 covers. It is imi)ossil)le to keep up a continuous succession of atrivinj? 

 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 8turge, 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 

 difters 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, liowever, iu 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 Buffalo 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 ti'ouble 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 larvae. I think that all the larvae in these regions must have died, 

 owing to the stagnant water, and that the gnats that we did have came from larvae 

 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 uot 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 larvae 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 larvae 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 larva;. — [G. A. Frierson, Louisiana, 

 September 27, 1891. 



Reply. — * * * ^^ ^^^.^ 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 



