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Conditions Just Prior to June 26

wind, paint, northeast, gnats and station


In order to account properly for the presence of certain insects found upon Rebecca shoal light-station on June 26 it is desirable to acquaint the reader with the conditions obtaining there in the period just preceding. From the lighthouse journal it was learned that on June 13 the keepers began painting the station, working that day upon the southeast side. At that time the wind was blowing freshly from the northeast. In other words, the air-current passed swiftly across the painted surface of the building; it was not on the lee side. Follow ing several hours of calm on June 14 a light north wind sprang up and continued until June 15, when it became somewhat westerly, finally dying out, to be followed by 36 hours of calm.

It is of interest to note than on June 15 a coat of white paint was applied to the southwest side of the dwelling, and particularly that 100 or more small gnats were later found stuck in this paint. Now, it will be seen that this southwest face of the building was, in the period following the application of the paint, in the lee of the north and north west winds; therefore, the insects seeking a resting-place on this surface were caught. Since they are not species that would have been brought in stores, it seems a fair conclusion that they were carried by the nor therly wind from the coast of Florida. The possibility is not excluded that these gnats were brought to the station on the northeast breeze of June 13 and harbored there until the application of the paint.

On June 17, following the 36 hours of calm, a light northeast wind held until June 18, when it became north-northeast. During June 19 its direction was from the east. After a day's calm, on June 21, a light breeze blew from the northeast, while that side of the dwelling was being painted. Here a single insect was later found in the paint,

a strong-flying damsel-fly which may have come down the wind and been able to make a landing, even though the air-current were sheering off across the surface painted.

An examination of the station on June 26 and 27 disclosed 6 living and 1 dead house-flies, Mut= domeatica, in the lower rooms ; one mutilated damsel-fly and one pentatomid on the balcony beneath and outside the lantern, and three dead gnats on the sills of the storm panes inside. The gnats no doubt ascended from the dwelling below and had been unable to find their way out. In addition to these—which, in all probability, reached the station by flight—many larder pests were discovered, including two species of moths, one breeding in stale wheat flour and the other in packages of raisins, bean weevils (Bruchus obtectu8) in dried beans, and a heavy infestation of weevils in two cases of the pilot bread which the keepers are required to keep on hand as a provision against want during possible prolonged periods of inability to secure their usual provisions from Key West. Each biscuit con tained upward of two dozen larva and adults.

Upon inquiry of the keepers it appeared that on June 19 "one or two mosquitoes" had been observed by them in their living quarters, but that this was a rare occurrence. The wind on the two preceding days had been from the northeast and north-northeast, so that the source may well have been the coast of Florida. It is probable that had a careful lookout been kept at that time several other specimens would have been noted.