210 Papers from the Department of Marine Biology. 



THE OCCURRENCE OF OTHER DIPTERA AT REBECCA SHOAL. 



Besides mosquitoes and house-flies several species of Diptera visited 

 Rebecca Shoal light-station during the period of observation. On 

 June 29, with a moderate east wind blowing, a Tabanid of the sort 

 commonly called greenheads settled upon the freshly painted railing of 

 the platform, where it was captured; another was taken on July 7. 

 Again the wind was blowing lightly from the east, indicating that these 

 large flies were borne westward along the reef and were able to cross 

 the 24 miles of open water between Marquesas and Rebecca Shoal 

 station. Tabanus is not uncommon on Loggerhead Key. 



Blow-flies of two species were also noted at the lighthouse and 5 

 were taken, 1 on June 27 and 2 on July 8, 1 on the 9th, and the last on 

 the 10th. It will be seen from the table on page 202 that on all these 

 days the winds were from the east. 



The only other Dipteran which visited Rebecca Shoal was a small 

 gnat taken just before dusk on July 2. Again the wind was in the east. 



OTHER INSECTS NOTED AT REBECCA SHOAL STATION. 



Other orders of insects were but meagerly represented at Rebecca 

 Shoal. As noted above, a single damsel-fly was caught in paint applied 

 to the building on June 21. A large dragon-fly was seen to approach 

 the station on July 5 ; it alighted on the roof of the lantern at the very 

 top of the structure, and when an attempt was made to capture it with 

 a hand-net it escaped and disappeared to the southwest. Although a 

 lookout was kept for it throughout the rest of the day nothing further 

 was seen of the specimen, thus indicating that its long flight from the 

 northward had not exhausted its strength. One specimen of the 

 Neuropteran called green-eyed lace-wing, Chrysopa, came to the station 

 on July 8. 



One Lepidopteran made the passage from Cuba to Rebecca Shoal on 

 the southerly winds which were responsible for the fhghts of mos- 

 quitoes and house-flies. On the morning of July 12, 1 had just reached 

 the platform on the southwest side of the station when a large moth 

 alighted upon one of the davits. Its capture proved it to be one of 

 remarkable beauty and strength, Syntomeida epilais. Its form, similar 

 to that of the Sphingidse, suggested such speed and endurance as 

 might well sustain it over a flight of 95 miles. 



EVIDENCE THAT ODONATA AND LEPIDOPTERA MIGRATE 

 TO TORTUGAS. 



Mention has just been made of a dragon-fly which visited Rebecca 

 Shoal station. At times these insects are numerous at Tortugas, both 

 on Loggerhead and East Kej^s, where vegetation is abundant. In 

 July 1914 within an hour I captured a score at East Key. On the 

 i sland, whose extent is about 6 acres, there were at that time at least 



